129 lines
4.4 KiB
Plaintext
129 lines
4.4 KiB
Plaintext
# Copyright (c) 2021 Intel Corporation
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#
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# SPDX-License-Identifier: Apache-2.0
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menu "Heap and Memory Allocation"
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config SYS_HEAP_VALIDATE
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bool "Enable internal heap validity checking"
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help
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The sys_heap implementation is instrumented for extensive
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internal validation. Leave this off by default, unless
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modifying the heap code or (maybe) when running in
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environments that require sensitive detection of memory
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corruption.
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config SYS_HEAP_ALLOC_LOOPS
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int "Number of tries in the inner heap allocation loop"
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default 3
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help
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The sys_heap allocator bounds the number of tries from the
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smallest chunk level (the one that might not fit the
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requested allocation) to maintain constant time performance.
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Setting this to a high level will cause the heap to return
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more successful allocations in situations of high
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fragmentation, at the cost of potentially significant
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(linear time) searching of the free list. The default is
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three, which results in an allocator with good statistical
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properties ("most" allocations that fit will succeed) but
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keeps the maximum runtime at a tight bound so that the heap
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is useful in locked or ISR contexts.
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config SYS_HEAP_RUNTIME_STATS
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bool "System heap runtime statistics"
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help
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Gather system heap runtime statistics.
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config SYS_HEAP_LISTENER
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bool "Enable sys_heap event notifications"
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select HEAP_LISTENER
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help
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This allows application to listen for sys_heap events,
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such as memory allocation and de-allocation.
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config HEAP_LISTENER
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bool
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help
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Hidden option to enable API for registering and notifying
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listeners of certain events related to a heap usage,
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such as the heap resize.
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choice
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prompt "Supported heap sizes"
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depends on !64BIT
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default SYS_HEAP_SMALL_ONLY if (SRAM_SIZE <= 256)
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default SYS_HEAP_AUTO
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help
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Heaps using reduced-size chunk headers can accommodate so called
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"small" heaps with a total size of 262136 bytes or less.
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Heaps using full-size chunk headers can have a total size up to
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16383 megabytes. The overhead is of course bigger.
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On 32-bit system the tradeoff is selectable between:
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- "small" heaps with low memory and runtime overhead;
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- "big" heaps with bigger memory overhead even for small heaps;
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- "auto" providing optimal memory overhead in all cases but with
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a higher runtime overhead and somewhat bigger code footprint.
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On 64-bit systems the "big" chunk header size conveniently provides
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the needed alignment on returned memory allocations. Small chunk
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headers would require alignment padding up to the big header size
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anyway so "big" heap is the only option in that case.
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config SYS_HEAP_SMALL_ONLY
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bool "Support for small heaps only"
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help
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Select this to optimize the code and memory usage if all your
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heaps are 262136 bytes or less.
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config SYS_HEAP_BIG_ONLY
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bool "Support for big heaps only"
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help
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Select this to optimize the code for big heaps only. This can
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accommodate any heap size but memory usage won't be as
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efficient with small sized heaps.
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config SYS_HEAP_AUTO
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bool "Support for both small and big heaps at run time"
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help
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This option optimizes memory usage for each heap according to
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their size albeit with some overhead in code size and execution.
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endchoice
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config SHARED_MULTI_HEAP
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bool "Shared multi-heap manager"
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help
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Enable support for a shared multi-heap manager that uses the
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multi-heap allocator to manage a set of reserved memory regions with
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different capabilities / attributes (cacheable, non-cacheable,
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etc...) defined in the DT.
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config SYS_MEM_BLOCKS
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bool "(Yet Another) Memory Blocks Allocator"
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help
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This enables support for memory block allocator where:
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() All memory blocks have a single fixed size.
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() Multiple blocks can be allocated or freed at the same time.
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() A group of blocks allocated together may not be contiguous.
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This is useful for operations such as scatter-gather DMA
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transfers.
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() Bookkeeping of allocated blocks is done outside of
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the associated buffer (unlike memory slab). This allows
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the buffer to reside in memory regions where these can be
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powered down to conserve energy.
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config SYS_MEM_BLOCKS_LISTENER
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bool "Enable Memory Blocks Allocator event notifications"
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depends on SYS_MEM_BLOCKS
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select HEAP_LISTENER
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help
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This allows application to listen for memory blocks allocator
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events, such as memory allocation and de-allocation.
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endmenu
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