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zephyr/kernel/include/offsets_short.h

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kernel/arch: consolidate tTCS and TNANO definitions There was a lot of duplication between architectures for the definition of threads and the "nanokernel" guts. These have been consolidated. Now, a common file kernel/unified/include/kernel_structs.h holds the common definitions. Architectures provide two files to complement it: kernel_arch_data.h and kernel_arch_func.h. The first one contains at least the struct _thread_arch and struct _kernel_arch data structures, as well as the struct _callee_saved and struct _caller_saved register layouts. The second file contains anything that needs what is provided by the common stuff in kernel_structs.h. Those two files are only meant to be included in kernel_structs.h in very specific locations. The thread data structure has been separated into three major parts: common struct _thread_base and struct k_thread, and arch-specific struct _thread_arch. The first and third ones are included in the second. The struct s_NANO data structure has been split into two: common struct _kernel and arch-specific struct _kernel_arch. The latter is included in the former. Offsets files have also changed: nano_offsets.h has been renamed kernel_offsets.h and is still included by the arch-specific offsets.c. Also, since the thread and kernel data structures are now made of sub-structures, offsets have to be added to make up the full offset. Some of these additions have been consolidated in shorter symbols, available from kernel/unified/include/offsets_short.h, which includes an arch-specific offsets_arch_short.h. Most of the code include offsets_short.h now instead of offsets.h. Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-08 23:36:50 +08:00
/*
* Copyright (c) 2016 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _offsets_short__h_
#define _offsets_short__h_
#include <offsets.h>
#include <offsets_short_arch.h>
/* kernel */
/* main */
#define _kernel_offset_to_nested \
(___kernel_t_nested_OFFSET)
#define _kernel_offset_to_irq_stack \
(___kernel_t_irq_stack_OFFSET)
#define _kernel_offset_to_current \
(___kernel_t_current_OFFSET)
#define _kernel_offset_to_idle \
(___kernel_t_idle_OFFSET)
#define _kernel_offset_to_current_fp \
(___kernel_t_current_fp_OFFSET)
kernel/arch: enhance the "ready thread" cache The way the ready thread cache was implemented caused it to not always be "hot", i.e. there could be some misses, which happened when the cached thread was taken out of the ready queue. When that happened, it was not replaced immediately, since doing so could mean that the replacement might not run because the flow could be interrupted and another thread could take its place. This was the more conservative approach that insured that moving a thread to the cache would never be wasted. However, this caused two problems: 1. The cache could not be refilled until another thread context-switched in, since there was no thread in the cache to compare priorities against. 2. Interrupt exit code would always have to call into C to find what thread to run when the current thread was not coop and did not have the scheduler locked. Furthermore, it was possible for this code path to encounter a cold cache and then it had to find out what thread to run the long way. To fix this, filling the cache is now more aggressive, i.e. the next thread to put in the cache is found even in the case the current cached thread is context-switched out. This ensures the interrupt exit code is much faster on the slow path. In addition, since finding the next thread to run is now always "get it from the cache", which is a simple fetch from memory (_kernel.ready_q.cache), there is no need to call the more complex C code. On the ARM FRDM K64F board, this improvement is seen: Before: 1- Measure time to switch from ISR back to interrupted task switching time is 215 tcs = 1791 nsec 2- Measure time from ISR to executing a different task (rescheduled) switch time is 315 tcs = 2625 nsec After: 1- Measure time to switch from ISR back to interrupted task switching time is 130 tcs = 1083 nsec 2- Measure time from ISR to executing a different task (rescheduled) switch time is 225 tcs = 1875 nsec These are the most dramatic improvements, but most of the numbers generated by the latency_measure test are improved. Fixes ZEP-1401. Change-Id: I2eaac147048b1ec71a93bd0a285e743a39533973 Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-12-02 23:37:27 +08:00
#define _kernel_offset_to_ready_q_cache \
(___kernel_t_ready_q_OFFSET + ___ready_q_t_cache_OFFSET)
kernel/arch: consolidate tTCS and TNANO definitions There was a lot of duplication between architectures for the definition of threads and the "nanokernel" guts. These have been consolidated. Now, a common file kernel/unified/include/kernel_structs.h holds the common definitions. Architectures provide two files to complement it: kernel_arch_data.h and kernel_arch_func.h. The first one contains at least the struct _thread_arch and struct _kernel_arch data structures, as well as the struct _callee_saved and struct _caller_saved register layouts. The second file contains anything that needs what is provided by the common stuff in kernel_structs.h. Those two files are only meant to be included in kernel_structs.h in very specific locations. The thread data structure has been separated into three major parts: common struct _thread_base and struct k_thread, and arch-specific struct _thread_arch. The first and third ones are included in the second. The struct s_NANO data structure has been split into two: common struct _kernel and arch-specific struct _kernel_arch. The latter is included in the former. Offsets files have also changed: nano_offsets.h has been renamed kernel_offsets.h and is still included by the arch-specific offsets.c. Also, since the thread and kernel data structures are now made of sub-structures, offsets have to be added to make up the full offset. Some of these additions have been consolidated in shorter symbols, available from kernel/unified/include/offsets_short.h, which includes an arch-specific offsets_arch_short.h. Most of the code include offsets_short.h now instead of offsets.h. Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-08 23:36:50 +08:00
/* end - kernel */
/* threads */
/* main */
#define _thread_offset_to_callee_saved \
(___thread_t_callee_saved_OFFSET)
/* base */
kernel/arch: optimize memory use of some thread fields Some thread fields were 32-bit wide, when they are not even close to using that full range of values. They are instead changed to 8-bit fields. - prio can fit in one byte, limiting the priorities range to -128 to 127 - recursive scheduler locking can be limited to 255; a rollover results most probably from a logic error - flags are split into execution flags and thread states; 8 bits is enough for each of them currently, with at worst two states and four flags to spare (on x86, on other archs, there are six flags to spare) Doing this saves 8 bytes per stack. It also sets up an incoming enhancement when checking if the current thread is preemptible on interrupt exit. Change-Id: Ieb5321a5b99f99173b0605dd4a193c3bc7ddabf4 Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-12-22 04:38:54 +08:00
#define _thread_offset_to_thread_state \
(___thread_t_base_OFFSET + ___thread_base_t_thread_state_OFFSET)
#define _thread_offset_to_execution_flags \
(___thread_t_base_OFFSET + ___thread_base_t_execution_flags_OFFSET)
kernel/arch: consolidate tTCS and TNANO definitions There was a lot of duplication between architectures for the definition of threads and the "nanokernel" guts. These have been consolidated. Now, a common file kernel/unified/include/kernel_structs.h holds the common definitions. Architectures provide two files to complement it: kernel_arch_data.h and kernel_arch_func.h. The first one contains at least the struct _thread_arch and struct _kernel_arch data structures, as well as the struct _callee_saved and struct _caller_saved register layouts. The second file contains anything that needs what is provided by the common stuff in kernel_structs.h. Those two files are only meant to be included in kernel_structs.h in very specific locations. The thread data structure has been separated into three major parts: common struct _thread_base and struct k_thread, and arch-specific struct _thread_arch. The first and third ones are included in the second. The struct s_NANO data structure has been split into two: common struct _kernel and arch-specific struct _kernel_arch. The latter is included in the former. Offsets files have also changed: nano_offsets.h has been renamed kernel_offsets.h and is still included by the arch-specific offsets.c. Also, since the thread and kernel data structures are now made of sub-structures, offsets have to be added to make up the full offset. Some of these additions have been consolidated in shorter symbols, available from kernel/unified/include/offsets_short.h, which includes an arch-specific offsets_arch_short.h. Most of the code include offsets_short.h now instead of offsets.h. Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-08 23:36:50 +08:00
#define _thread_offset_to_prio \
(___thread_t_base_OFFSET + ___thread_base_t_prio_OFFSET)
#define _thread_offset_to_sched_locked \
(___thread_t_base_OFFSET + ___thread_base_t_sched_locked_OFFSET)
kernel/arch: inspect prio/sched_locked together for preemptibility These two fields in the thread structure control the preemptibility of a thread. sched_locked is decremented when the scheduler gets locked, which means that the scheduler is locked for values 0xff to 0x01, since it can be locked recursively. A thread is coop if its priority is negative, thus if the prio field value is 0x80 to 0xff when looked at as an unsigned value. By putting them end-to-end, this means that a thread is non-preemptible if the bundled value is greater than or equal to 0x0080. This is the only thing the interrupt exit code has to check to decide to try a reschedule or not. Change-Id: I902d36c14859d0d7a951a6aa1bea164613821aca Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-12-22 05:00:35 +08:00
#define _thread_offset_to_preempt \
(___thread_t_base_OFFSET + ___thread_base_t_preempt_OFFSET)
kernel/arch: consolidate tTCS and TNANO definitions There was a lot of duplication between architectures for the definition of threads and the "nanokernel" guts. These have been consolidated. Now, a common file kernel/unified/include/kernel_structs.h holds the common definitions. Architectures provide two files to complement it: kernel_arch_data.h and kernel_arch_func.h. The first one contains at least the struct _thread_arch and struct _kernel_arch data structures, as well as the struct _callee_saved and struct _caller_saved register layouts. The second file contains anything that needs what is provided by the common stuff in kernel_structs.h. Those two files are only meant to be included in kernel_structs.h in very specific locations. The thread data structure has been separated into three major parts: common struct _thread_base and struct k_thread, and arch-specific struct _thread_arch. The first and third ones are included in the second. The struct s_NANO data structure has been split into two: common struct _kernel and arch-specific struct _kernel_arch. The latter is included in the former. Offsets files have also changed: nano_offsets.h has been renamed kernel_offsets.h and is still included by the arch-specific offsets.c. Also, since the thread and kernel data structures are now made of sub-structures, offsets have to be added to make up the full offset. Some of these additions have been consolidated in shorter symbols, available from kernel/unified/include/offsets_short.h, which includes an arch-specific offsets_arch_short.h. Most of the code include offsets_short.h now instead of offsets.h. Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-08 23:36:50 +08:00
#define _thread_offset_to_esf \
(___thread_t_arch_OFFSET + ___thread_arch_t_esf_OFFSET)
/* end - threads */
#endif /* _offsets_short__h_ */