commit 68fb3ca0e408e00db1c3f8fccdfa19e274c033be upstream.
In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with
outputs") I did the gcc workaround unconditionally, because the cause of
the bad code generation wasn't entirely clear.
In the meantime, Jakub Jelinek debugged the issue, and has come up with
a fix in gcc [2], which also got backported to the still maintained
branches of gcc-11, gcc-12 and gcc-13.
Note that while the fix technically wasn't in the original gcc-14
branch, Jakub says:
"while it is true that no GCC 14 snapshots until today (or whenever the
fix will be committed) have the fix, for GCC trunk it is up to the
distros to use the latest snapshot if they use it at all and would
allow better testing of the kernel code without the workaround, so
that if there are other issues they won't be discovered years later.
Most userland code doesn't actually use asm goto with outputs..."
so we will consider gcc-14 to be fixed - if somebody is using gcc
snapshots of the gcc-14 before the fix, they should upgrade.
Note that while the bug goes back to gcc-11, in practice other gcc
changes seem to have effectively hidden it since gcc-12.1 as per a
bisect by Jakub. So even a gcc-14 snapshot without the fix likely
doesn't show actual problems.
Also, make the default 'asm_goto_output()' macro mark the asm as
volatile by hand, because of an unrelated gcc issue [1] where it doesn't
match the documented behavior ("asm goto is always volatile").
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2]
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Requested-by: Jakub Jelinek <jakub@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 21528c69a0d8483f7c6345b1a0bc8d8975e9a172 upstream.
Documentation/filesystems/ramfs-rootfs-initramfs.rst states:
If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by
default. To force ramfs, add "rootfstype=ramfs" to the kernel command
line.
This currently does not work when root= is provided since then
saved_root_name contains a string and rootfstype= is ignored. Therefore,
ramfs is currently always chosen when root= is provided.
The current behavior for rootfs's filesystem is:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs
unspecified | tmpfs | tmpfs
unspecified | ramfs | ramfs
provided | ignored | ramfs
rootfstype= should be respected regardless whether root= is given,
as shown below:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs (as before)
unspecified | tmpfs | tmpfs (as before)
unspecified | ramfs | ramfs (as before)
provided | unspecified | ramfs (compatibility with before)
provided | tmpfs | tmpfs (new)
provided | ramfs | ramfs (new)
This table represents the new behavior.
Fixes: 6e19eded36 ("initmpfs: use initramfs if rootfstype= or root= specified")
Cc: <stable@vger.kernel.org>
Signed-off-by: Rob Landley <rob@landley.net>
Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/
Reviewed-and-Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8001f49394e353f035306a45bcf504f06fca6355 upstream.
The code that checks for unknown boot options is unaware of the sysctl
alias facility, which maps bootparams to sysctl values. If a user sets
an old value that has a valid alias, a message about an invalid
parameter will be printed during boot, and the parameter will get passed
to init. Fix by checking for the existence of aliased parameters in the
unknown boot parameter code. If an alias exists, don't return an error
or pass the value to init.
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: 0a477e1ae2 ("kernel/sysctl: support handling command line aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 98dfdd9ee9 ]
Users of KERNFS should select it to enforce its being built, so
do this to prevent a build error.
In file included from ../kernel/sched/build_utility.c:97:
../kernel/sched/psi.c: In function 'psi_trigger_poll':
../kernel/sched/psi.c:1479:17: error: implicit declaration of function 'kernfs_generic_poll' [-Werror=implicit-function-declaration]
1479 | kernfs_generic_poll(t->of, wait);
Fixes: aff037078e ("sched/psi: use kernfs polling functions for PSI trigger polling")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: lore.kernel.org/r/202307310732.r65EQFY0-lkp@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5b93a83649 upstream.
Move poking_init() up a bunch; specifically move it right after
mm_init() which is right before ftrace_init().
This will allow simplifying ftrace text poking which currently has
a bunch of exceptions for early boot.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.881703081@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit af80602799 upstream.
In order to allow using mm_alloc() much earlier, move initializing
mm_cachep into mm_init().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.751153381@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 439e17576e upstream
Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and
remove the weak fallback from the core code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9df9d2f047 upstream
X86 is reworking the boot process so that initializations which are not
required during early boot can be moved into the late boot process and out
of the fragile and restricted initial boot phase.
arch_cpu_finalize_init() is the obvious place to do such initializations,
but arch_cpu_finalize_init() is invoked too late in start_kernel() e.g. for
initializing the FPU completely. fork_init() requires that the FPU is
initialized as the size of task_struct on X86 depends on the size of the
required FPU register buffer.
Fortunately none of the init calls between calibrate_delay() and
arch_cpu_finalize_init() is relevant for the functionality of
arch_cpu_finalize_init().
Invoke it right after calibrate_delay() where everything which is relevant
for arch_cpu_finalize_init() has been set up already.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/r/20230613224545.612182854@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 61235b24b9 upstream
Everything is converted over to arch_cpu_finalize_init(). Remove the
check_bugs() leftovers including the empty stubs in asm-generic, alpha,
parisc, powerpc and xtensa.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7725acaa4f upstream
check_bugs() has become a dumping ground for all sorts of activities to
finalize the CPU initialization before running the rest of the init code.
Most are empty, a few do actual bug checks, some do alternative patching
and some cobble a CPU advertisement string together....
Aside of that the current implementation requires duplicated function
declaration and mostly empty header files for them.
Provide a new function arch_cpu_finalize_init(). Provide a generic
declaration if CONFIG_ARCH_HAS_CPU_FINALIZE_INIT is selected and a stub
inline otherwise.
This requires a temporary #ifdef in start_kernel() which will be removed
along with check_bugs() once the architectures are converted over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224544.957805717@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0da6e5fd6c upstream.
We started disabling '-Warray-bounds' for gcc-12 originally on s390,
because it resulted in some warnings that weren't realistically fixable
(commit 8b202ee21839: "s390: disable -Warray-bounds").
That s390-specific issue was then found to be less common elsewhere, but
generic (see f0be87c42cbd: "gcc-12: disable '-Warray-bounds' universally
for now"), and then later expanded the version check was expanded to
gcc-11 (5a41237ad1d4: "gcc: disable -Warray-bounds for gcc-11 too").
And it turns out that I was much too optimistic in thinking that it's
all going to go away, and here we are with gcc-13 showing all the same
issues. So instead of expanding this one version at a time, let's just
disable it for gcc-11+, and put an end limit to it only when we actually
find a solution.
Yes, I'm sure some of this is because the kernel just does odd things
(like our "container_of()" use, but also knowingly playing games with
things like linker tables and array layouts).
And yes, some of the warnings are likely signs of real bugs, but when
there are hundreds of false positives, that doesn't really help.
Oh well.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a41237ad1 upstream.
We had already disabled this warning for gcc-12 due to bugs in the value
range analysis, but it turns out we end up having some similar problems
with gcc-11.3 too, so let's disable it there too.
Older gcc versions end up being increasingly less relevant, and
hopefully clang and newer version of gcc (ie gcc-13) end up working
reliably enough that we still get the build coverage even when we
disable this for some versions.
Link: https://lore.kernel.org/all/20221227002941.GA2691687@roeck-us.net/
Link: https://lore.kernel.org/all/D8BDBF66-E44C-45D4-9758-BAAA4F0C1998@kernel.org/
Cc: Kees Cook <kees@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using dash as /bin/sh, the CC_HAS_ASM_GOTO_TIED_OUTPUT test fails
with a syntax error which is not the one we are looking for:
<stdin>: In function ‘foo’:
<stdin>:1:29: warning: missing terminating " character
<stdin>:1:29: error: missing terminating " character
<stdin>:2:5: error: expected ‘:’ before ‘+’ token
<stdin>:2:7: warning: missing terminating " character
<stdin>:2:7: error: missing terminating " character
<stdin>:2:5: error: expected declaration or statement at end of input
Removing '\n' solves this.
Fixes: 1aa0e8b144 ("Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Valentin Schneider makes crash-kexec work properly when invoked from
an NMI-time panic.
- ntfs bugfixes from Hawkins Jiawei
- Jiebin Sun improves IPC msg scalability by replacing atomic_t's with
percpu counters.
- nilfs2 cleanups from Minghao Chi
- lots of other single patches all over the tree!
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Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- hfs and hfsplus kmap API modernization (Fabio Francesco)
- make crash-kexec work properly when invoked from an NMI-time panic
(Valentin Schneider)
- ntfs bugfixes (Hawkins Jiawei)
- improve IPC msg scalability by replacing atomic_t's with percpu
counters (Jiebin Sun)
- nilfs2 cleanups (Minghao Chi)
- lots of other single patches all over the tree!
* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
proc: test how it holds up with mapping'less process
mailmap: update Frank Rowand email address
ia64: mca: use strscpy() is more robust and safer
init/Kconfig: fix unmet direct dependencies
ia64: update config files
nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
fork: remove duplicate included header files
init/main.c: remove unnecessary (void*) conversions
proc: mark more files as permanent
nilfs2: remove the unneeded result variable
nilfs2: delete unnecessary checks before brelse()
checkpatch: warn for non-standard fixes tag style
usr/gen_init_cpio.c: remove unnecessary -1 values from int file
ipc/msg: mitigate the lock contention with percpu counter
percpu: add percpu_counter_add_local and percpu_counter_sub_local
fs/ocfs2: fix repeated words in comments
relay: use kvcalloc to alloc page array in relay_alloc_page_array
proc: make config PROC_CHILDREN depend on PROC_FS
fs: uninline inode_maybe_inc_iversion()
...
Commit 3c07bfce92a5 ("proc: make config PROC_CHILDREN depend on PROC_FS")
make config PROC_CHILDREN depend on PROC_FS.
When CONFIG_PROC_FS is not set and CONFIG_CHECKPOINT_RESTORE=y,
make menuconfig screams like this:
WARNING: unmet direct dependencies detected for PROC_CHILDREN
Depends on [n]: PROC_FS [=n]
Selected by [y]:
- CHECKPOINT_RESTORE [=y]
CHECKPOINT_RESTORE would select PROC_CHILDREN which depends on PROC_FS,
so add depends on PROC_FS to CHECKPOINT_RESTORE to fix this.
Link: https://lkml.kernel.org/r/20220929070057.59044-1-renzhijie2@huawei.com
Fixes: 3c07bfce92a5 ("proc: make config PROC_CHILDREN depend on PROC_FS")
Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
linux-next for a couple of months without, to my knowledge, any negative
reports (or any positive ones, come to that).
- Also the Maple Tree from Liam R. Howlett. An overlapping range-based
tree for vmas. It it apparently slight more efficient in its own right,
but is mainly targeted at enabling work to reduce mmap_lock contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
(https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
This has yet to be addressed due to Liam's unfortunately timed
vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down to
the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
- Remove potentially incomplete targets when Kbuid is interrupted by
SIGINT etc. in case GNU Make may miss to do that when stderr is piped
to another program.
- Rewrite the single target build so it works more correctly.
- Fix rpm-pkg builds with V=1.
- List top-level subdirectories in ./Kbuild.
- Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms.
- Avoid two different modules in lib/zstd/ having shared code, which
potentially causes building the common code as build-in and modular
back-and-forth.
- Unify two modpost invocations to optimize the build process.
- Remove head-y syntax in favor of linker scripts for placing particular
sections in the head of vmlinux.
- Bump the minimal GNU Make version to 3.82.
- Clean up misc Makefiles and scripts.
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Merge tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Remove potentially incomplete targets when Kbuid is interrupted by
SIGINT etc in case GNU Make may miss to do that when stderr is piped
to another program.
- Rewrite the single target build so it works more correctly.
- Fix rpm-pkg builds with V=1.
- List top-level subdirectories in ./Kbuild.
- Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in
kallsyms.
- Avoid two different modules in lib/zstd/ having shared code, which
potentially causes building the common code as build-in and modular
back-and-forth.
- Unify two modpost invocations to optimize the build process.
- Remove head-y syntax in favor of linker scripts for placing
particular sections in the head of vmlinux.
- Bump the minimal GNU Make version to 3.82.
- Clean up misc Makefiles and scripts.
* tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits)
docs: bump minimal GNU Make version to 3.82
ia64: simplify esi object addition in Makefile
Revert "kbuild: Check if linker supports the -X option"
kbuild: rebuild .vmlinux.export.o when its prerequisite is updated
kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o
zstd: Fixing mixed module-builtin objects
kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols
kallsyms: take the input file instead of reading stdin
kallsyms: drop duplicated ignore patterns from kallsyms.c
kbuild: reuse mksysmap output for kallsyms
mksysmap: update comment about __crc_*
kbuild: remove head-y syntax
kbuild: use obj-y instead extra-y for objects placed at the head
kbuild: hide error checker logs for V=1 builds
kbuild: re-run modpost when it is updated
kbuild: unify two modpost invocations
kbuild: move vmlinux.o rule to the top Makefile
kbuild: move .vmlinux.objs rule to Makefile.modpost
kbuild: list sub-directories in ./Kbuild
Makefile.compiler: replace cc-ifversion with compiler-specific macros
...
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Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
- Huawei reported that when they updated their kernel from 4.4 to
something much newer, some userspace code they had broke, the culprit
being the accidental removal of O_NONBLOCK from /dev/random way back
in 5.6. It's been gone for over 2 years now and this is the first
we've heard of it, but userspace breakage is userspace breakage, so
O_NONBLOCK is now back.
- Use randomness from hardware RNGs much more often during early boot,
at the same interval that crng reseeds are done, from Dominik.
- A semantic change in hardware RNG throttling, so that the hwrng
framework can properly feed random.c with randomness from hardware
RNGs that aren't specifically marked as creditable.
A related patch coming to you via Herbert's hwrng tree depends on
this one, not to compile, but just to function properly, so you may
want to merge this PULL before that one.
- A fix to clamp credited bits from the interrupts pool to the size of
the pool sample. This is mainly just a theoretical fix, as it'd be
pretty hard to exceed it in practice.
- Oracle reported that InfiniBand TCP latency regressed by around
10-15% after a change a few cycles ago made at the request of the RT
folks, in which we hoisted a somewhat rare operation (1 in 1024
times) out of the hard IRQ handler and into a workqueue, a pretty
common and boring pattern.
It turns out, though, that scheduling a worker from there has
overhead of its own, whereas scheduling a timer on that same CPU for
the next jiffy amortizes better and doesn't incur the same overhead.
I also eliminated a cache miss by moving the work_struct (and
subsequently, the timer_list) to below a critical cache line, so that
the more critical members that are accessed on every hard IRQ aren't
split between two cache lines.
- The boot-time initialization of the RNG has been split into two
approximate phases: what we can accomplish before timekeeping is
possible and what we can accomplish after.
This winds up being useful so that we can use RDRAND to seed the RNG
before CONFIG_SLAB_FREELIST_RANDOM=y systems initialize slabs, in
addition to other early uses of randomness. The effect is that
systems with RDRAND (or a bootloader seed) will never see any
warnings at all when setting CONFIG_WARN_ALL_UNSEEDED_RANDOM=y. And
kfence benefits from getting a better seed of its own.
- Small systems without much entropy sometimes wind up putting some
truncated serial number read from flash into hostname, so contribute
utsname changes to the RNG, without crediting.
- Add smaller batches to serve requests for smaller integers, and make
use of them when people ask for random numbers bounded by a given
compile-time constant. This has positive effects all over the tree,
most notably in networking and kfence.
- The original jitter algorithm intended (I believe) to schedule the
timer for the next jiffy, not the next-next jiffy, yet it used
mod_timer(jiffies + 1), which will fire on the next-next jiffy,
instead of what I believe was intended, mod_timer(jiffies), which
will fire on the next jiffy. So fix that.
- Fix a comment typo, from William.
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
random: clear new batches when bringing new CPUs online
random: fix typos in get_random_bytes() comment
random: schedule jitter credit for next jiffy, not in two jiffies
prandom: make use of smaller types in prandom_u32_max
random: add 8-bit and 16-bit batches
utsname: contribute changes to RNG
random: use init_utsname() instead of utsname()
kfence: use better stack hash seed
random: split initialization into early step and later step
random: use expired timer rather than wq for mixing fast pool
random: avoid reading two cache lines on irq randomness
random: clamp credited irq bits to maximum mixed
random: throttle hwrng writes if no entropy is credited
random: use hwgenerator randomness more frequently at early boot
random: restore O_NONBLOCK support
- Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
- Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
- Freezer:
- Rewrite the core freezer to behave better wrt thawing and be simpler
in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
all the fallout.
- Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
- Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
Freezer:
- Rewrite the core freezer to behave better wrt thawing and be
simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
fixing/adjusting all the fallout.
Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() &
replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications"
* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
sched: Fix more TASK_state comparisons
sched: Fix TASK_state comparisons
sched/fair: Move call to list_last_entry() in detach_tasks
sched/fair: Cleanup loop_max and loop_break
sched/fair: Make sure to try to detach at least one movable task
sched: Show PF_flag holes
freezer,sched: Rewrite core freezer logic
sched: Widen TAKS_state literals
sched/wait: Add wait_event_state()
sched/completion: Add wait_for_completion_state()
sched: Add TASK_ANY for wait_task_inactive()
sched: Change wait_task_inactive()s match_state
freezer,umh: Clean up freezer/initrd interaction
freezer: Have {,un}lock_system_sleep() save/restore flags
sched: Rename task_running() to task_on_cpu()
sched/fair: Cleanup for SIS_PROP
sched/fair: Default to false in test_idle_cores()
sched/fair: Remove useless check in select_idle_core()
sched/fair: Avoid double search on same cpu
sched/fair: Remove redundant check in select_idle_smt()
...
- Remove our now never-true definitions for pgd_huge() and p4d_leaf().
- Add pte_needs_flush() and huge_pmd_needs_flush() for 64-bit.
- Add support for syscall wrappers.
- Add support for KFENCE on 64-bit.
- Update 64-bit HV KVM to use the new guest state entry/exit accounting API.
- Support execute-only memory when using the Radix MMU (P9 or later).
- Implement CONFIG_PARAVIRT_TIME_ACCOUNTING for pseries guests.
- Updates to our linker script to move more data into read-only sections.
- Allow the VDSO to be randomised on 32-bit.
- Many other small features and fixes.
Thanks to: Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Christophe
Leroy, David Hildenbrand, Disha Goel, Fabiano Rosas, Gaosheng Cui, Gustavo A. R. Silva,
Haren Myneni, Hari Bathini, Jilin Yuan, Joel Stanley, Kajol Jain, Kees Cook, Krzysztof
Kozlowski, Laurent Dufour, Liang He, Li Huafei, Lukas Bulwahn, Madhavan Srinivasan, Nathan
Chancellor, Nathan Lynch, Nicholas Miehlbradt, Nicholas Piggin, Pali Rohár, Rohan McLure,
Russell Currey, Sachin Sant, Segher Boessenkool, Shrikanth Hegde, Tyrel Datwyler, Wolfram
Sang, ye xingchen, Zheng Yongjun.
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Merge tag 'powerpc-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Remove our now never-true definitions for pgd_huge() and p4d_leaf().
- Add pte_needs_flush() and huge_pmd_needs_flush() for 64-bit.
- Add support for syscall wrappers.
- Add support for KFENCE on 64-bit.
- Update 64-bit HV KVM to use the new guest state entry/exit accounting
API.
- Support execute-only memory when using the Radix MMU (P9 or later).
- Implement CONFIG_PARAVIRT_TIME_ACCOUNTING for pseries guests.
- Updates to our linker script to move more data into read-only
sections.
- Allow the VDSO to be randomised on 32-bit.
- Many other small features and fixes.
Thanks to Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira
Rajeev, Christophe Leroy, David Hildenbrand, Disha Goel, Fabiano Rosas,
Gaosheng Cui, Gustavo A. R. Silva, Haren Myneni, Hari Bathini, Jilin
Yuan, Joel Stanley, Kajol Jain, Kees Cook, Krzysztof Kozlowski, Laurent
Dufour, Liang He, Li Huafei, Lukas Bulwahn, Madhavan Srinivasan, Nathan
Chancellor, Nathan Lynch, Nicholas Miehlbradt, Nicholas Piggin, Pali
Rohár, Rohan McLure, Russell Currey, Sachin Sant, Segher Boessenkool,
Shrikanth Hegde, Tyrel Datwyler, Wolfram Sang, ye xingchen, and Zheng
Yongjun.
* tag 'powerpc-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits)
KVM: PPC: Book3S HV: Fix stack frame regs marker
powerpc: Don't add __powerpc_ prefix to syscall entry points
powerpc/64s/interrupt: Fix stack frame regs marker
powerpc/64: Fix msr_check_and_set/clear MSR[EE] race
powerpc/64s/interrupt: Change must-hard-mask interrupt check from BUG to WARN
powerpc/pseries: Add firmware details to the hardware description
powerpc/powernv: Add opal details to the hardware description
powerpc: Add device-tree model to the hardware description
powerpc/64: Add logical PVR to the hardware description
powerpc: Add PVR & CPU name to hardware description
powerpc: Add hardware description string
powerpc/configs: Enable PPC_UV in powernv_defconfig
powerpc/configs: Update config files for removed/renamed symbols
powerpc/mm: Fix UBSAN warning reported on hugetlb
powerpc/mm: Always update max/min_low_pfn in mem_topology_setup()
powerpc/mm/book3s/hash: Rename flush_tlb_pmd_range
powerpc: Drops STABS_DEBUG from linker scripts
powerpc/64s: Remove lost/old comment
powerpc/64s: Remove old STAB comment
powerpc: remove orphan systbl_chk.sh
...
The void pointer object can be directly assigned to different structure
objects, it does not need to be cast.
Link: https://lkml.kernel.org/r/20220928014539.11046-1-zhoujie@nfschina.com
Signed-off-by: Zhou jie <zhoujie@nfschina.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since 2d1c498072 ("mm: memcontrol: make swap tracking an integral part
of memory control"), CONFIG_MEMCG_SWAP hasn't been a user-visible config
option anymore, it just means CONFIG_MEMCG && CONFIG_SWAP.
Update the sites accordingly and drop the symbol.
[ While touching the docs, remove two references to CONFIG_MEMCG_KMEM,
which hasn't been a user-visible symbol for over half a decade. ]
Link: https://lkml.kernel.org/r/20220926135704.400818-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kmsan_init_shadow() scans the mappings created at boot time and creates
metadata pages for those mappings.
When the memblock allocator returns pages to pagealloc, we reserve 2/3 of
those pages and use them as metadata for the remaining 1/3. Once KMSAN
starts, every page allocated by pagealloc has its associated shadow and
origin pages.
kmsan_initialize() initializes the bookkeeping for init_task and enables
KMSAN.
Link: https://lkml.kernel.org/r/20220915150417.722975-18-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The full RNG initialization relies on some timestamps, made possible
with initialization functions like time_init() and timekeeping_init().
However, these are only available rather late in initialization.
Meanwhile, other things, such as memory allocator functions, make use of
the RNG much earlier.
So split RNG initialization into two phases. We can provide arch
randomness very early on, and then later, after timekeeping and such are
available, initialize the rest.
This ensures that, for example, slabs are properly randomized if RDRAND
is available. Without this, CONFIG_SLAB_FREELIST_RANDOM=y loses a degree
of its security, because its random seed is potentially deterministic,
since it hasn't yet incorporated RDRAND. It also makes it possible to
use a better seed in kfence, which currently relies on only the cycle
counter.
Another positive consequence is that on systems with RDRAND, running
with CONFIG_WARN_ALL_UNSEEDED_RANDOM=y results in no warnings at all.
One subtle side effect of this change is that on systems with no RDRAND,
RDTSC is now only queried by random_init() once, committing the moment
of the function call, instead of multiple times as before. This is
intentional, as the multiple RDTSCs in a loop before weren't
accomplishing very much, with jitter being better provided by
try_to_generate_entropy(). Plus, filling blocks with RDTSC is still
being done in extract_entropy(), which is necessarily called before
random bytes are served anyway.
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Now that UTS_VERSION was separated out, this header can be generated
much earlier, and probably the top Makefile is a better place to do it
than init/Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kbuild builds init/built-in.a twice; first during the ordinary
directory descending, second from scripts/link-vmlinux.sh.
We do this because UTS_VERSION contains the build version and the
timestamp. We cannot update it during the normal directory traversal
since we do not yet know if we need to update vmlinux. UTS_VERSION is
temporarily calculated, but omitted from the update check. Otherwise,
vmlinux would be rebuilt every time.
When Kbuild results in running link-vmlinux.sh, it increments the
version number in the .version file and takes the timestamp at that
time to really fix UTS_VERSION.
However, updating the same file twice is a footgun. To avoid nasty
timestamp issues, all build artifacts that depend on init/built-in.a
are atomically generated in link-vmlinux.sh, where some of them do not
need rebuilding.
To fix this issue, this commit changes as follows:
[1] Split UTS_VERSION out to include/generated/utsversion.h from
include/generated/compile.h
include/generated/utsversion.h is generated just before the
vmlinux link. It is generated under include/generated/ because
some decompressors (s390, x86) use UTS_VERSION.
[2] Split init_uts_ns and linux_banner out to init/version-timestamp.c
from init/version.c
init_uts_ns and linux_banner contain UTS_VERSION. During the ordinary
directory descending, they are compiled with __weak and used to
determine if vmlinux needs relinking. Just before the vmlinux link,
they are compiled without __weak to embed the real version and
timestamp.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This is unneeded since commit 073a9ecb3a ("init/version.c: remove
Version_<LINUX_VERSION_CODE> symbol").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Having most of the new files in place, we now enable Rust support
in the build system, including `Kconfig` entries related to Rust,
the Rust configuration printer and a few other bits.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Douglas Su <d0u9.su@outlook.com>
Signed-off-by: Douglas Su <d0u9.su@outlook.com>
Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Co-developed-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Co-developed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Patch series "Introducing the Maple Tree"
The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.
The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.
The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.
The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.
Davidlor said
: Yes I like the maple tree, and at this stage I don't think we can ask for
: more from this series wrt the MM - albeit there seems to still be some
: folks reporting breakage. Fundamentally I see Liam's work to (re)move
: complexity out of the MM (not to say that the actual maple tree is not
: complex) by consolidating the three complimentary data structures very
: much worth it considering performance does not take a hit. This was very
: much a turn off with the range locking approach, which worst case scenario
: incurred in prohibitive overhead. Also as Liam and Matthew have
: mentioned, RCU opens up a lot of nice performance opportunities, and in
: addition academia[1] has shown outstanding scalability of address spaces
: with the foundation of replacing the locked rbtree with RCU aware trees.
A similar work has been discovered in the academic press
https://pdos.csail.mit.edu/papers/rcuvm:asplos12.pdf
Sheer coincidence. We designed our tree with the intention of solving the
hardest problem first. Upon settling on a b-tree variant and a rough
outline, we researched ranged based b-trees and RCU b-trees and did find
that article. So it was nice to find reassurances that we were on the
right path, but our design choice of using ranges made that paper unusable
for us.
This patch (of 70):
The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.
The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.
The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.
The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.
There is additional BUG_ON() calls added within the tree, most of which
are in debug code. These will be replaced with a WARN_ON() call in the
future. There is also additional BUG_ON() calls within the code which
will also be reduced in number at a later date. These exist to catch
things such as out-of-range accesses which would crash anyways.
Link: https://lkml.kernel.org/r/20220906194824.2110408-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220906194824.2110408-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As my_inptr is only used in __init function unpack_to_rootfs(), mark it as
__initdata to allow it be freed after boot.
Link: https://lkml.kernel.org/r/20220827071116.83078-1-wuchi.zero@gmail.com
Signed-off-by: wuchi <wuchi.zero@gmail.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Martin Wilck <mwilck@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In commit 2f1ee0913c ("Revert "mm: use early_pfn_to_nid in
page_ext_init""), we call page_ext_init() after page_alloc_init_late() to
avoid some panic problem. It seems that we cannot track early page
allocations in current kernel even if page structure has been initialized
early.
This patch introduces a new boot parameter 'early_page_ext' to resolve
this problem. If we pass it to the kernel, page_ext_init() will be moved
up and the feature 'deferred initialization of struct pages' will be
disabled to initialize the page allocator early and prevent the panic
problem above. It can help us to catch early page allocations. This is
useful especially when we find that the free memory value is not the same
right after different kernel booting.
[akpm@linux-foundation.org: fix section issue by removing __meminitdata]
Link: https://lkml.kernel.org/r/20220825102714.669-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
handle_initrd() marks itself as PF_FREEZER_SKIP in order to ensure
that the UMH, which is going to freeze the system, doesn't
indefinitely wait for it's caller.
Rework things by adding UMH_FREEZABLE to indicate the completion is
freezable.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114648.791019324@infradead.org
Distro kernels tend to be moving to VIRT_CPU_ACCOUNTING_GEN, and there
is not much reason why PPC64 should be special here. Remove the special
case and make the ppc64 and pseries defconfigs use GEN accounting
(others will use TICK, as-per Kconfig defaults).
VIRT_CPU_ACCOUNTING_NATIVE does provide scaled vtime and stolen time
apportioned between system and user time, and vtime accounting is not
unconditionally enabled, and possibly other things. But it would be
better at this point to extend GEN to cover important missing features
rather than directing users back to a less used option.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220902085316.2071519-4-npiggin@gmail.com
- Fix workaround for Cortex-A76 erratum #1286807
- Add workaround for AMU erratum #2457168 on Cortex-A510
- Drop reference to removed CONFIG_ARCH_RANDOM #define
- Fix parsing of the "rodata=full" cmdline option
- Fix a bunch of issues in the SME register state switching and sigframe code
- Fix incorrect extraction of the CTR_EL0.CWG register field
- Fix ACPI cache topology probing when the PPTT is not present
- Trivial comment and whitespace fixes
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"A bumper crop of arm64 fixes for -rc3.
The largest change is fixing our parsing of the 'rodata=full' command
line option, which kstrtobool() started treating as 'rodata=false'.
The fix actually makes the parsing of that option much less fragile
and updates the documentation at the same time.
We still have a boot issue pending when KASLR is disabled at compile
time, but there's a fresh fix on the list which I'll send next week if
it holds up to testing.
Summary:
- Fix workaround for Cortex-A76 erratum #1286807
- Add workaround for AMU erratum #2457168 on Cortex-A510
- Drop reference to removed CONFIG_ARCH_RANDOM #define
- Fix parsing of the "rodata=full" cmdline option
- Fix a bunch of issues in the SME register state switching and sigframe code
- Fix incorrect extraction of the CTR_EL0.CWG register field
- Fix ACPI cache topology probing when the PPTT is not present
- Trivial comment and whitespace fixes"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64/sme: Don't flush SVE register state when handling SME traps
arm64/sme: Don't flush SVE register state when allocating SME storage
arm64/signal: Flush FPSIMD register state when disabling streaming mode
arm64/signal: Raise limit on stack frames
arm64/cache: Fix cache_type_cwg() for register generation
arm64/sysreg: Guard SYS_FIELD_ macros for asm
arm64/sysreg: Directly include bitfield.h
arm64: cacheinfo: Fix incorrect assignment of signed error value to unsigned fw_level
arm64: errata: add detection for AMEVCNTR01 incrementing incorrectly
arm64: fix rodata=full
arm64: Fix comment typo
docs/arm64: elf_hwcaps: unify newlines in HWCAP lists
arm64: adjust KASLR relocation after ARCH_RANDOM removal
arm64: Fix match_list for erratum 1286807 on Arm Cortex-A76
On arm64, "rodata=full" has been suppored (but not documented) since
commit:
c55191e96c ("arm64: mm: apply r/o permissions of VM areas to its linear alias as well")
As it's necessary to determine the rodata configuration early during
boot, arm64 has an early_param() handler for this, whereas init/main.c
has a __setup() handler which is run later.
Unfortunately, this split meant that since commit:
f9a40b0890 ("init/main.c: return 1 from handled __setup() functions")
... passing "rodata=full" would result in a spurious warning from the
__setup() handler (though RO permissions would be configured
appropriately).
Further, "rodata=full" has been broken since commit:
0d6ea3ac94 ("lib/kstrtox.c: add "false"/"true" support to kstrtobool()")
... which caused strtobool() to parse "full" as false (in addition to
many other values not documented for the "rodata=" kernel parameter.
This patch fixes this breakage by:
* Moving the core parameter parser to an __early_param(), such that it
is available early.
* Adding an (optional) arch hook which arm64 can use to parse "full".
* Updating the documentation to mention that "full" is valid for arm64.
* Having the core parameter parser handle "on" and "off" explicitly,
such that any undocumented values (e.g. typos such as "ful") are
reported as errors rather than being silently accepted.
Note that __setup() and early_param() have opposite conventions for
their return values, where __setup() uses 1 to indicate a parameter was
handled and early_param() uses 0 to indicate a parameter was handled.
Fixes: f9a40b0890 ("init/main.c: return 1 from handled __setup() functions")
Fixes: 0d6ea3ac94 ("lib/kstrtox.c: add "false"/"true" support to kstrtobool()")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jagdish Gediya <jvgediya@linux.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220817154022.3974645-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
GCC has supported asm goto since 4.5, and Clang has since version 9.0.0.
The minimum supported versions of these tools for the build according to
Documentation/process/changes.rst are 5.1 and 11.0.0 respectively.
Remove the feature detection script, Kconfig option, and clean up some
fallback code that is no longer supported.
The removed script was also testing for a GCC specific bug that was
fixed in the 4.7 release.
Also remove workarounds for bpftrace using clang older than 9.0.0, since
other BPF backend fixes are required at this point.
Link: https://lore.kernel.org/lkml/CAK7LNATSr=BXKfkdW8f-H5VT_w=xBpT2ZQcZ7rm6JfkdE+QnmA@mail.gmail.com/
Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637
Acked-by: Borislav Petkov <bp@suse.de>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Remove the support for -O3 (CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3)
- Fix error of rpm-pkg cross-builds
- Support riscv for checkstack tool
- Re-enable -Wformwat warnings for Clang
- Clean up modpost, Makefiles, and misc scripts
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Merge tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Remove the support for -O3 (CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3)
- Fix error of rpm-pkg cross-builds
- Support riscv for checkstack tool
- Re-enable -Wformwat warnings for Clang
- Clean up modpost, Makefiles, and misc scripts
* tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
modpost: remove .symbol_white_list field entirely
modpost: remove unneeded .symbol_white_list initializers
modpost: add PATTERNS() helper macro
modpost: shorten warning messages in report_sec_mismatch()
Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost"
modpost: use more reliable way to get fromsec in section_rel(a)()
modpost: add array range check to sec_name()
modpost: refactor get_secindex()
kbuild: set EXIT trap before creating temporary directory
modpost: remove unused Elf_Sword macro
Makefile.extrawarn: re-enable -Wformat for clang
kbuild: add dtbs_prepare target
kconfig: Qt5: tell the user which packages are required
modpost: use sym_get_data() to get module device_table data
modpost: drop executable ELF support
checkstack: add riscv support for scripts/checkstack.pl
kconfig: shorten the temporary directory name for cc-option
scripts: headers_install.sh: Update config leak ignore entries
kbuild: error out if $(INSTALL_MOD_PATH) contains % or :
kbuild: error out if $(KBUILD_EXTMOD) contains % or :
...
For the 6.0 merge window the modules code shifts to cleanup and minor fixes
effort. This is becomes much easier to do and review now due to the code
split to its own directory from effort on the last kernel release. I expect
to see more of this with time and as we expand on test coverage in the future.
The cleanups and fixes come from usual suspects such as Christophe Leroy and
Aaron Tomlin but there are also some other contributors.
One particular minor fix worth mentioning is from Helge Deller, where he spotted
a *forever* incorrect natural alignment on both ELF section header tables:
* .altinstructions
* __bug_table sections
A lot of back and forth went on in trying to determine the ill effects of this
misalignment being present for years and it has been determined there should
be no real ill effects unless you have a buggy exception handler. Helge actually
hit one of these buggy exception handlers on parisc which is how he ended up
spotting this issue. When implemented correctly these paths with incorrect
misalignment would just mean a performance penalty, but given that we are
dealing with alternatives on modules and with the __bug_table (where info
regardign BUG()/WARN() file/line information associated with it is stored)
this really shouldn't be a big deal.
The only other change with mentioning is the kmap() with kmap_local_page()
and my only concern with that was on what is done after preemption, but the
virtual addresses are restored after preemption. This is only used on module
decompression.
This all has sit on linux-next for a while except the kmap stuff which has
been there for 3 weeks.
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Merge tag 'modules-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
"For the 6.0 merge window the modules code shifts to cleanup and minor
fixes effort. This becomes much easier to do and review now due to the
code split to its own directory from effort on the last kernel
release. I expect to see more of this with time and as we expand on
test coverage in the future. The cleanups and fixes come from usual
suspects such as Christophe Leroy and Aaron Tomlin but there are also
some other contributors.
One particular minor fix worth mentioning is from Helge Deller, where
he spotted a *forever* incorrect natural alignment on both ELF section
header tables:
* .altinstructions
* __bug_table sections
A lot of back and forth went on in trying to determine the ill effects
of this misalignment being present for years and it has been
determined there should be no real ill effects unless you have a buggy
exception handler. Helge actually hit one of these buggy exception
handlers on parisc which is how he ended up spotting this issue. When
implemented correctly these paths with incorrect misalignment would
just mean a performance penalty, but given that we are dealing with
alternatives on modules and with the __bug_table (where info regardign
BUG()/WARN() file/line information associated with it is stored) this
really shouldn't be a big deal.
The only other change with mentioning is the kmap() with
kmap_local_page() and my only concern with that was on what is done
after preemption, but the virtual addresses are restored after
preemption. This is only used on module decompression.
This all has sit on linux-next for a while except the kmap stuff which
has been there for 3 weeks"
* tag 'modules-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
module: Replace kmap() with kmap_local_page()
module: Show the last unloaded module's taint flag(s)
module: Use strscpy() for last_unloaded_module
module: Modify module_flags() to accept show_state argument
module: Move module's Kconfig items in kernel/module/
MAINTAINERS: Update file list for module maintainers
module: Use vzalloc() instead of vmalloc()/memset(0)
modules: Ensure natural alignment for .altinstructions and __bug_table sections
module: Increase readability of module_kallsyms_lookup_name()
module: Fix ERRORs reported by checkpatch.pl
module: Add support for default value for module async_probe
fatfs, autofs, squashfs, procfs, etc.
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Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc updates from Andrew Morton:
"Updates to various subsystems which I help look after. lib, ocfs2,
fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
material this time"
* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
scripts/gdb: ensure the absolute path is generated on initial source
MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
mailmap: add linux.dev alias for Brendan Higgins
mailmap: update Kirill's email
profile: setup_profiling_timer() is moslty not implemented
ocfs2: fix a typo in a comment
ocfs2: use the bitmap API to simplify code
ocfs2: remove some useless functions
lib/mpi: fix typo 'the the' in comment
proc: add some (hopefully) insightful comments
bdi: remove enum wb_congested_state
kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
squashfs: support reading fragments in readahead call
squashfs: implement readahead
squashfs: always build "file direct" version of page actor
Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
fs/ocfs2: Fix spelling typo in comment
ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
proc: fix test for "vsyscall=xonly" boot option
...
* threadgroup_rwsem write locking is skipped when configuring controllers in
empty subtrees. Combined with CLONE_INTO_CGROUP, this allows the common
static usage pattern to not grab threadgroup_rwsem at all (glibc still
doesn't seem ready for CLONE_INTO_CGROUP unfortunately).
* threadgroup_rwsem used to be put into non-percpu mode by default due to
latency concerns in specific use cases. There's no reason for everyone
else to pay for it. Make the behavior optional.
* psi no longer allocates memory when disabled.
along with some code cleanups.
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Merge tag 'cgroup-for-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
"Several core optimizations:
- threadgroup_rwsem write locking is skipped when configuring
controllers in empty subtrees.
Combined with CLONE_INTO_CGROUP, this allows the common static
usage pattern to not grab threadgroup_rwsem at all (glibc still
doesn't seem ready for CLONE_INTO_CGROUP unfortunately).
- threadgroup_rwsem used to be put into non-percpu mode by default
due to latency concerns in specific use cases. There's no reason
for everyone else to pay for it. Make the behavior optional.
- psi no longer allocates memory when disabled.
... along with some code cleanups"
* tag 'cgroup-for-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Skip subtree root in cgroup_update_dfl_csses()
cgroup: remove "no" prefixed mount options
cgroup: Make !percpu threadgroup_rwsem operations optional
cgroup: Add "no" prefixed mount options
cgroup: Elide write-locking threadgroup_rwsem when updating csses on an empty subtree
cgroup.c: remove redundant check for mixable cgroup in cgroup_migrate_vet_dst
cgroup.c: add helper __cset_cgroup_from_root to cleanup duplicated codes
psi: dont alloc memory for psi by default
earth-shaking:
- More Chinese translations, and an update to the Italian translations.
The Japanese, Korean, and traditional Chinese translations are
more-or-less unmaintained at this point, instead.
- Some build-system performance improvements.
- The removal of the archaic submitting-drivers.rst document, with the
movement of what useful material that remained into other docs.
- Improvements to sphinx-pre-install to, hopefully, give more useful
suggestions.
- A number of build-warning fixes
Plus the usual collection of typo fixes, updates, and more.
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Merge tag 'docs-6.0' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"This was a moderately busy cycle for documentation, but nothing
all that earth-shaking:
- More Chinese translations, and an update to the Italian
translations.
The Japanese, Korean, and traditional Chinese translations
are more-or-less unmaintained at this point, instead.
- Some build-system performance improvements.
- The removal of the archaic submitting-drivers.rst document,
with the movement of what useful material that remained into
other docs.
- Improvements to sphinx-pre-install to, hopefully, give more
useful suggestions.
- A number of build-warning fixes
Plus the usual collection of typo fixes, updates, and more"
* tag 'docs-6.0' of git://git.lwn.net/linux: (92 commits)
docs: efi-stub: Fix paths for x86 / arm stubs
Docs/zh_CN: Update the translation of sched-stats to 5.19-rc8
Docs/zh_CN: Update the translation of pci to 5.19-rc8
Docs/zh_CN: Update the translation of pci-iov-howto to 5.19-rc8
Docs/zh_CN: Update the translation of usage to 5.19-rc8
Docs/zh_CN: Update the translation of testing-overview to 5.19-rc8
Docs/zh_CN: Update the translation of sparse to 5.19-rc8
Docs/zh_CN: Update the translation of kasan to 5.19-rc8
Docs/zh_CN: Update the translation of iio_configfs to 5.19-rc8
doc:it_IT: align Italian documentation
docs: Remove spurious tag from admin-guide/mm/overcommit-accounting.rst
Documentation: process: Update email client instructions for Thunderbird
docs: ABI: correct QEMU fw_cfg spec path
doc/zh_CN: remove submitting-driver reference from docs
docs: zh_TW: align to submitting-drivers removal
docs: zh_CN: align to submitting-drivers removal
docs: ko_KR: howto: remove reference to removed submitting-drivers
docs: ja_JP: howto: remove reference to removed submitting-drivers
docs: it_IT: align to submitting-drivers removal
docs: process: remove outdated submitting-drivers.rst
...
This pull request contains the following branches:
doc.2022.06.21a: Documentation updates.
fixes.2022.07.19a: Miscellaneous fixes.
nocb.2022.07.19a: Callback-offload updates, perhaps most notably a new
RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to
be offloaded at boot time, regardless of kernel boot parameters.
This is useful to battery-powered systems such as ChromeOS
and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel
boot parameter prevents offloaded callbacks from interfering
with real-time workloads and with energy-efficiency mechanisms.
poll.2022.07.21a: Polled grace-period updates, perhaps most notably
making these APIs account for both normal and expedited grace
periods.
rcu-tasks.2022.06.21a: Tasks RCU updates, perhaps most notably reducing
the CPU overhead of RCU tasks trace grace periods by more than
a factor of two on a system with 15,000 tasks. The reduction
is expected to increase with the number of tasks, so it seems
reasonable to hypothesize that a system with 150,000 tasks might
see a 20-fold reduction in CPU overhead.
torture.2022.06.21a: Torture-test updates.
ctxt.2022.07.05a: Updates that merge RCU's dyntick-idle tracking into
context tracking, thus reducing the overhead of transitioning to
kernel mode from either idle or nohz_full userspace execution
for kernels that track context independently of RCU. This is
expected to be helpful primarily for kernels built with
CONFIG_NO_HZ_FULL=y.
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Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
- Documentation updates
- Miscellaneous fixes
- Callback-offload updates, perhaps most notably a new
RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be
offloaded at boot time, regardless of kernel boot parameters.
This is useful to battery-powered systems such as ChromeOS and
Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot
parameter prevents offloaded callbacks from interfering with
real-time workloads and with energy-efficiency mechanisms
- Polled grace-period updates, perhaps most notably making these APIs
account for both normal and expedited grace periods
- Tasks RCU updates, perhaps most notably reducing the CPU overhead of
RCU tasks trace grace periods by more than a factor of two on a
system with 15,000 tasks.
The reduction is expected to increase with the number of tasks, so it
seems reasonable to hypothesize that a system with 150,000 tasks
might see a 20-fold reduction in CPU overhead
- Torture-test updates
- Updates that merge RCU's dyntick-idle tracking into context tracking,
thus reducing the overhead of transitioning to kernel mode from
either idle or nohz_full userspace execution for kernels that track
context independently of RCU.
This is expected to be helpful primarily for kernels built with
CONFIG_NO_HZ_FULL=y
* tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits)
rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings
rcu: Diagnose extended sync_rcu_do_polled_gp() loops
rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings
rcutorture: Test polled expedited grace-period primitives
rcu: Add polled expedited grace-period primitives
rcutorture: Verify that polled GP API sees synchronous grace periods
rcu: Make Tiny RCU grace periods visible to polled APIs
rcu: Make polled grace-period API account for expedited grace periods
rcu: Switch polled grace-period APIs to ->gp_seq_polled
rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty
rcu/nocb: Add option to opt rcuo kthreads out of RT priority
rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread()
rcu/nocb: Add an option to offload all CPUs on boot
rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call
rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order
rcu/nocb: Add/del rdp to iterate from rcuog itself
rcu/tree: Add comment to describe GP-done condition in fqs loop
rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs()
rcu/kvfree: Remove useless monitor_todo flag
rcu: Cleanup RCU urgency state for offline CPU
...
API:
- Make proc files report fips module name and version.
Algorithms:
- Move generic SHA1 code into lib/crypto.
- Implement Chinese Remainder Theorem for RSA.
- Remove blake2s.
- Add XCTR with x86/arm64 acceleration.
- Add POLYVAL with x86/arm64 acceleration.
- Add HCTR2.
- Add ARIA.
Drivers:
- Add support for new CCP/PSP device ID in ccp.
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Merge tag 'v5.20-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
"API:
- Make proc files report fips module name and version
Algorithms:
- Move generic SHA1 code into lib/crypto
- Implement Chinese Remainder Theorem for RSA
- Remove blake2s
- Add XCTR with x86/arm64 acceleration
- Add POLYVAL with x86/arm64 acceleration
- Add HCTR2
- Add ARIA
Drivers:
- Add support for new CCP/PSP device ID in ccp"
* tag 'v5.20-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (89 commits)
crypto: tcrypt - Remove the static variable initialisations to NULL
crypto: arm64/poly1305 - fix a read out-of-bound
crypto: hisilicon/zip - Use the bitmap API to allocate bitmaps
crypto: hisilicon/sec - fix auth key size error
crypto: ccree - Remove a useless dma_supported() call
crypto: ccp - Add support for new CCP/PSP device ID
crypto: inside-secure - Add missing MODULE_DEVICE_TABLE for of
crypto: hisilicon/hpre - don't use GFP_KERNEL to alloc mem during softirq
crypto: testmgr - some more fixes to RSA test vectors
cyrpto: powerpc/aes - delete the rebundant word "block" in comments
hwrng: via - Fix comment typo
crypto: twofish - Fix comment typo
crypto: rmd160 - fix Kconfig "its" grammar
crypto: keembay-ocs-ecc - Drop if with an always false condition
Documentation: qat: rewrite description
Documentation: qat: Use code block for qat sysfs example
crypto: lib - add module license to libsha1
crypto: lib - make the sha1 library optional
crypto: lib - move lib/sha1.c into lib/crypto/
crypto: fips - make proc files report fips module name and version
...
CONFIG_KALLSYMS_ALL is required for kernel live patching which is a
common use case that is enabled in some major distros. Update the
Kconfig help text to reflect that.
While at it, s/e.g./i.e./ to match the text intention.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The difference in most compilers between `-O3` and `-O2` is mostly down
to whether loops with statically determinable trip counts are fully
unrolled vs unrolled to a multiple of SIMD width.
This patch is effectively a revert of
commit 15f5db60a1 ("kbuild,arc: add
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC") without re-adding
ARCH_CFLAGS
Ever since
commit cfdbc2e16e ("ARC: Build system: Makefiles, Kconfig, Linker
script")
ARC has been built with -O3, though the reason for doing so was not
specified in inline comments or the commit message. This commit does not
re-add -O3 to arch/arc/Makefile.
Folks looking to experiment with `-O3` (or any compiler flag for that
matter) may pass them along to the command line invocation of make:
$ make KCFLAGS=-O3
Code that looks to re-add an explicit Kconfig option for `-O3` should
provide:
1. A rigorous and reproducible performance profile of a reasonable
userspace workload that demonstrates a hot loop in the kernel that
would benefit from `-O3` over `-O2`.
2. Disassembly of said loop body before and after.
3. Provides stats on terms of increase in file size.
Link: https://lore.kernel.org/linux-kbuild/CA+55aFz2sNBbZyg-_i8_Ldr2e8o9dfvdSfHHuRzVtP2VMAUWPg@mail.gmail.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
3942a9bd7b ("locking, rcu, cgroup: Avoid synchronize_sched() in
__cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem
because the impiled synchronize_rcu() on write locking was pushing up the
latencies too much for android which constantly moves processes between
cgroups.
This makes the hotter paths - fork and exit - slower as they're always
forced into the slow path. There is no reason to force this on everyone
especially given that more common static usage pattern can now completely
avoid write-locking the rwsem. Write-locking is elided when turning on and
off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a
cgroup without grabbing the rwsem.
Restore the default percpu operations and introduce the mount option
"favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need
lower latencies for the dynamic operations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutn� <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Linus Torvalds