- 26 Apr, 2024 40 commits
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Suren Baghdasaryan authored
To avoid debug warnings while freeing reserved pages which were not allocated with usual allocators, mark their codetags as empty before freeing. Link: https://lkml.kernel.org/r/20240321163705.3067592-35-surenb@google.comSigned-off-by:
Suren Baghdasaryan <surenb@google.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Tested-by:
Andrew Morton <akpm@linux-foundation.org>
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Suren Baghdasaryan authored
objext objects are created with __GFP_NO_OBJ_EXT flag and therefore have no corresponding objext themselves (otherwise we would get an infinite recursion). When freeing these objects their codetag will be empty and when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled this will lead to false warnings. Introduce CODETAG_EMPTY special codetag value to mark allocations which intentionally lack codetag to avoid these warnings. Set objext codetags to CODETAG_EMPTY before freeing to indicate that the codetag is expected to be empty. Link: https://lkml.kernel.org/r/20240321163705.3067592-34-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Include allocations in show_mem reports. Link: https://lkml.kernel.org/r/20240321163705.3067592-33-surenb@google.comSigned-off-by:
Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Tested-by:
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Kent Overstreet authored
This gives better memory allocation profiling results; rhashtable allocations will be accounted to the code that initialized the rhashtable. [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-32-surenb@google.comSigned-off-by:
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Kent Overstreet authored
This wrapps all external vmalloc allocation functions with the alloc_hooks() wrapper, and switches internal allocations to _noprof variants where appropriate, for the new memory allocation profiling feature. [surenb@google.com: arch/um: fix forward declaration for vmalloc] Link: https://lkml.kernel.org/r/20240326073750.726636-1-surenb@google.com [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-5-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-31-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Redefine __alloc_percpu, __alloc_percpu_gfp and __alloc_reserved_percpu to record allocations and deallocations done by these functions. [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-6-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-30-surenb@google.comSigned-off-by:
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Kent Overstreet authored
To store codetag for every per-cpu allocation, a codetag reference is embedded into pcpuobj_ext when CONFIG_MEM_ALLOC_PROFILING=y. Hooks to use the newly introduced codetag are added. Link: https://lkml.kernel.org/r/20240321163705.3067592-29-surenb@google.comSigned-off-by:
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Kent Overstreet authored
Upcoming alloc tagging patches require a place to stash per-allocation metadata. We already do this when memcg is enabled, so this patch generalizes the obj_cgroup * vector in struct pcpu_chunk by creating a pcpu_obj_ext type, which we will be adding to in an upcoming patch - similarly to the previous slabobj_ext patch. Link: https://lkml.kernel.org/r/20240321163705.3067592-28-surenb@google.comSigned-off-by:
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Kent Overstreet authored
This adds hooks to mempools for correctly annotating mempool-backed allocations at the correct source line, so they show up correctly in /sys/kernel/debug/allocations. Various inline functions are converted to wrappers so that we can invoke alloc_hooks() in fewer places. [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-4-surenb@google.com [surenb@google.com: add missing mempool_create_node documentation] Link: https://lkml.kernel.org/r/20240402180835.1661905-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-27-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Redefine kmalloc, krealloc, kzalloc, kcalloc, etc. to record allocations and deallocations done by these functions. [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-7-surenb@google.com [rdunlap@infradead.org: fix kcalloc() kernel-doc warnings] Link: https://lkml.kernel.org/r/20240327044649.9199-1-rdunlap@infradead.org Link: https://lkml.kernel.org/r/20240321163705.3067592-26-surenb@google.comSigned-off-by:
Randy Dunlap <rdunlap@infradead.org> Reviewed-by:
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Kent Overstreet authored
Memory allocation profiling is turning krealloc() into a nontrivial macro - so for now, we need a helper for it. Until we have proper support on the rust side for memory allocation profiling this does mean that all Rust allocations will be accounted to the helper. Link: https://lkml.kernel.org/r/20240321163705.3067592-25-surenb@google.comSigned-off-by:
Alice Ryhl <aliceryhl@google.com> Acked-by:
Miguel Ojeda <ojeda@kernel.org> Tested-by:
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Suren Baghdasaryan authored
Account slab allocations using codetag reference embedded into slabobj_ext. Link: https://lkml.kernel.org/r/20240321163705.3067592-24-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
To store code tag for every slab object, a codetag reference is embedded into slabobj_ext when CONFIG_MEM_ALLOC_PROFILING=y. Link: https://lkml.kernel.org/r/20240321163705.3067592-23-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
For all page allocations to be tagged, page_ext has to be initialized before the first page allocation. Early tasks allocate their stacks using page allocator before alloc_node_page_ext() initializes page_ext area, unless early_page_ext is enabled. Therefore these allocations will generate a warning when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled. Enable early_page_ext whenever CONFIG_MEM_ALLOC_PROFILING_DEBUG=y to ensure page_ext initialization prior to any page allocation. This will have all the negative effects associated with early_page_ext, such as possible longer boot time, therefore we enable it only when debugging with CONFIG_MEM_ALLOC_PROFILING_DEBUG enabled and not universally for CONFIG_MEM_ALLOC_PROFILING. Link: https://lkml.kernel.org/r/20240321163705.3067592-22-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
When a non-compound multi-order page is freed, it is possible that a speculative reference keeps the page pinned. In this case we free all pages except for the first page, which will be freed later by the last put_page(). However the page passed to put_page() is indistinguishable from an order-0 page, so it cannot do the accounting, just as it cannot free the subsequent pages. Do the accounting here, where we free the pages. Link: https://lkml.kernel.org/r/20240321163705.3067592-21-surenb@google.comReported-by:
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Suren Baghdasaryan authored
When a high-order page is split into smaller ones, each newly split page should get its codetag. After the split each split page will be referencing the original codetag. The codetag's "bytes" counter remains the same because the amount of allocated memory has not changed, however the "calls" counter gets increased to keep the counter correct when these individual pages get freed. Link: https://lkml.kernel.org/r/20240321163705.3067592-20-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Redefine page allocators to record allocation tags upon their invocation. Instrument post_alloc_hook and free_pages_prepare to modify current allocation tag. [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-3-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-19-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
After redefining alloc_pages, all uses of that name are being replaced. Change the conflicting names to prevent preprocessor from replacing them when it's not intended. Link: https://lkml.kernel.org/r/20240321163705.3067592-18-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
As each allocation tag generates a per-cpu variable, more space is required to store them. Increase PERCPU_MODULE_RESERVE to provide enough area. A better long-term solution would be to allocate this memory dynamically. [surenb@google.com: increase PERCPU_MODULE_RESERVE to accommodate allocation tags] Link: https://lkml.kernel.org/r/20240406214044.1114406-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-17-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
The highest memory overhead from memory allocation profiling comes from page_ext objects. This overhead exists even if the feature is disabled but compiled-in. To avoid it, introduce an early boot parameter that prevents page_ext object creation. The new boot parameter is a tri-state with possible values of 0|1|never. When it is set to "never" the memory allocation profiling support is disabled, and overhead is minimized (currently no page_ext objects are allocated, in the future more overhead might be eliminated). As a result we also lose ability to enable memory allocation profiling at runtime (because there is no space to store alloctag references). Runtime sysctrl becomes read-only if the early boot parameter was set to "never". Note that the default value of this boot parameter depends on the CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT configuration. When CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT=n the boot parameter is set to "never", therefore eliminating any overhead. CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT=y results in boot parameter being set to 1 (enabled). This allows distributions to avoid any overhead by setting CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT=n config and with no changes to the kernel command line. We reuse sysctl.vm.mem_profiling boot parameter name in order to avoid introducing yet another control. This change turns it into a tri-state early boot parameter. Link: https://lkml.kernel.org/r/20240321163705.3067592-16-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Introduce helper functions to easily instrument page allocators by storing a pointer to the allocation tag associated with the code that allocated the page in a page_ext field. Link: https://lkml.kernel.org/r/20240321163705.3067592-15-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Introduce CONFIG_MEM_ALLOC_PROFILING which provides definitions to easily instrument memory allocators. It registers an "alloc_tags" codetag type with /proc/allocinfo interface to output allocation tag information when the feature is enabled. CONFIG_MEM_ALLOC_PROFILING_DEBUG is provided for debugging the memory allocation profiling instrumentation. Memory allocation profiling can be enabled or disabled at runtime using /proc/sys/vm/mem_profiling sysctl when CONFIG_MEM_ALLOC_PROFILING_DEBUG=n. CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT enables memory allocation profiling by default. [surenb@google.com: Documentation/filesystems/proc.rst: fix allocinfo title] Link: https://lkml.kernel.org/r/20240326073813.727090-1-surenb@google.com [surenb@google.com: do limited memory accounting for modules with ARCH_NEEDS_WEAK_PER_CPU] Link: https://lkml.kernel.org/r/20240402180933.1663992-2-surenb@google.com [klarasmodin@gmail.com: explicitly include irqflags.h in alloc_tag.h] Link: https://lkml.kernel.org/r/20240407133252.173636-1-klarasmodin@gmail.com [surenb@google.com: fix alloc_tag_init() to prevent passing NULL to PTR_ERR()] Link: https://lkml.kernel.org/r/20240417003349.2520094-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-14-surenb@google.comSigned-off-by:
Klara Modin <klarasmodin@gmail.com> Tested-by:
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Suren Baghdasaryan authored
Skip freeing module's data section if there are non-zero allocation tags because otherwise, once these allocations are freed, the access to their code tag would cause UAF. Link: https://lkml.kernel.org/r/20240321163705.3067592-13-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Add support for code tagging from dynamically loaded modules. Link: https://lkml.kernel.org/r/20240321163705.3067592-12-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Add basic infrastructure to support code tagging which stores tag common information consisting of the module name, function, file name and line number. Provide functions to register a new code tag type and navigate between code tags. Link: https://lkml.kernel.org/r/20240321163705.3067592-11-surenb@google.comCo-developed-by:
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Suren Baghdasaryan authored
Introduce objext_flags to store additional objext flags unrelated to memcg. Link: https://lkml.kernel.org/r/20240321163705.3067592-10-surenb@google.comSigned-off-by:
Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by:
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Suren Baghdasaryan authored
Slab extension objects can't be allocated before slab infrastructure is initialized. Some caches, like kmem_cache and kmem_cache_node, are created before slab infrastructure is initialized. Objects from these caches can't have extension objects. Introduce SLAB_NO_OBJ_EXT slab flag to mark these caches and avoid creating extensions for objects allocated from these slabs. Link: https://lkml.kernel.org/r/20240321163705.3067592-9-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations when allocating slabobj_ext on a slab. Link: https://lkml.kernel.org/r/20240321163705.3067592-8-surenb@google.comSigned-off-by:
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Suren Baghdasaryan authored
Currently slab pages can store only vectors of obj_cgroup pointers in page->memcg_data. Introduce slabobj_ext structure to allow more data to be stored for each slab object. Wrap obj_cgroup into slabobj_ext to support current functionality while allowing to extend slabobj_ext in the future. Link: https://lkml.kernel.org/r/20240321163705.3067592-7-surenb@google.comSigned-off-by:
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Kent Overstreet authored
We're introducing alloc tagging, which tracks memory allocations by callsite. Converting alloc_inode_sb() to a macro means allocations will be tracked by its caller, which is a bit more useful. Link: https://lkml.kernel.org/r/20240321163705.3067592-6-surenb@google.comSigned-off-by:
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Kent Overstreet authored
These symbols are used to denote section boundaries: by always including them we can unify loading sections from modules with loading built-in sections, which leads to some significant cleanup. Link: https://lkml.kernel.org/r/20240321163705.3067592-5-surenb@google.comSigned-off-by:
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Kent Overstreet authored
It seems we need to be more forceful with the compiler on this one. This is done for performance reasons only. Link: https://lkml.kernel.org/r/20240321163705.3067592-4-surenb@google.comSigned-off-by:
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Kent Overstreet authored
Needed to avoid a new circular dependency with the memory allocation profiling series. Naturally, a whole bunch of files needed to include vmalloc.h that were previously getting it implicitly. Link: https://lkml.kernel.org/r/20240321163705.3067592-3-surenb@google.comSigned-off-by:
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Kent Overstreet authored
Patch series "Memory allocation profiling", v6. Overview: Low overhead [1] per-callsite memory allocation profiling. Not just for debug kernels, overhead low enough to be deployed in production. Example output: root@moria-kvm:~# sort -rn /proc/allocinfo 127664128 31168 mm/page_ext.c:270 func:alloc_page_ext 56373248 4737 mm/slub.c:2259 func:alloc_slab_page 14880768 3633 mm/readahead.c:247 func:page_cache_ra_unbounded 14417920 3520 mm/mm_init.c:2530 func:alloc_large_system_hash 13377536 234 block/blk-mq.c:3421 func:blk_mq_alloc_rqs 11718656 2861 mm/filemap.c:1919 func:__filemap_get_folio 9192960 2800 kernel/fork.c:307 func:alloc_thread_stack_node 4206592 4 net/netfilter/nf_conntrack_core.c:2567 func:nf_ct_alloc_hashtable 4136960 1010 drivers/staging/ctagmod/ctagmod.c:20 [ctagmod] func:ctagmod_start 3940352 962 mm/memory.c:4214 func:alloc_anon_folio 2894464 22613 fs/kernfs/dir.c:615 func:__kernfs_new_node ... Usage: kconfig options: - CONFIG_MEM_ALLOC_PROFILING - CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT - CONFIG_MEM_ALLOC_PROFILING_DEBUG adds warnings for allocations that weren't accounted because of a missing annotation sysctl: /proc/sys/vm/mem_profiling Runtime info: /proc/allocinfo Notes: [1]: Overhead To measure the overhead we are comparing the following configurations: (1) Baseline with CONFIG_MEMCG_KMEM=n (2) Disabled by default (CONFIG_MEM_ALLOC_PROFILING=y && CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=n) (3) Enabled by default (CONFIG_MEM_ALLOC_PROFILING=y && CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=y) (4) Enabled at runtime (CONFIG_MEM_ALLOC_PROFILING=y && CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=n && /proc/sys/vm/mem_profiling=1) (5) Baseline with CONFIG_MEMCG_KMEM=y && allocating with __GFP_ACCOUNT (6) Disabled by default (CONFIG_MEM_ALLOC_PROFILING=y && CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=n) && CONFIG_MEMCG_KMEM=y (7) Enabled by default (CONFIG_MEM_ALLOC_PROFILING=y && CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=y) && CONFIG_MEMCG_KMEM=y Performance overhead: To evaluate performance we implemented an in-kernel test executing multiple get_free_page/free_page and kmalloc/kfree calls with allocation sizes growing from 8 to 240 bytes with CPU frequency set to max and CPU affinity set to a specific CPU to minimize the noise. Below are results from running the test on Ubuntu 22.04.2 LTS with 6.8.0-rc1 kernel on 56 core Intel Xeon: kmalloc pgalloc (1 baseline) 6.764s 16.902s (2 default disabled) 6.793s (+0.43%) 17.007s (+0.62%) (3 default enabled) 7.197s (+6.40%) 23.666s (+40.02%) (4 runtime enabled) 7.405s (+9.48%) 23.901s (+41.41%) (5 memcg) 13.388s (+97.94%) 48.460s (+186.71%) (6 def disabled+memcg) 13.332s (+97.10%) 48.105s (+184.61%) (7 def enabled+memcg) 13.446s (+98.78%) 54.963s (+225.18%) Memory overhead: Kernel size: text data bss dec diff (1) 26515311 18890222 17018880 62424413 (2) 26524728 19423818 16740352 62688898 264485 (3) 26524724 19423818 16740352 62688894 264481 (4) 26524728 19423818 16740352 62688898 264485 (5) 26541782 18964374 16957440 62463596 39183 Memory consumption on a 56 core Intel CPU with 125GB of memory: Code tags: 192 kB PageExts: 262144 kB (256MB) SlabExts: 9876 kB (9.6MB) PcpuExts: 512 kB (0.5MB) Total overhead is 0.2% of total memory. Benchmarks: Hackbench tests run 100 times: hackbench -s 512 -l 200 -g 15 -f 25 -P baseline disabled profiling enabled profiling avg 0.3543 0.3559 (+0.0016) 0.3566 (+0.0023) stdev 0.0137 0.0188 0.0077 hackbench -l 10000 baseline disabled profiling enabled profiling avg 6.4218 6.4306 (+0.0088) 6.5077 (+0.0859) stdev 0.0933 0.0286 0.0489 stress-ng tests: stress-ng --class memory --seq 4 -t 60 stress-ng --class cpu --seq 4 -t 60 Results posted at: https://evilpiepirate.org/~kent/memalloc_prof_v4_stress-ng/ [2] https://lore.kernel.org/all/20240306182440.2003814-1-surenb@google.com/ This patch (of 37): The next patch drops vmalloc.h from a system header in order to fix a circular dependency; this adds it to all the files that were pulling it in implicitly. [kent.overstreet@linux.dev: fix arch/alpha/lib/memcpy.c] Link: https://lkml.kernel.org/r/20240327002152.3339937-1-kent.overstreet@linux.dev [surenb@google.com: fix arch/x86/mm/numa_32.c] Link: https://lkml.kernel.org/r/20240402180933.1663992-1-surenb@google.com [kent.overstreet@linux.dev: a few places were depending on sizes.h] Link: https://lkml.kernel.org/r/20240404034744.1664840-1-kent.overstreet@linux.dev [arnd@arndb.de: fix mm/kasan/hw_tags.c] Link: https://lkml.kernel.org/r/20240404124435.3121534-1-arnd@kernel.org [surenb@google.com: fix arc build] Link: https://lkml.kernel.org/r/20240405225115.431056-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-1-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-2-surenb@google.comSigned-off-by:Arnd Bergmann <arnd@arndb.de> Reviewed-by:
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Randy Dunlap authored
Memory profiling introduces macros as hooks for function-level allocation profiling[1]. Memory allocation functions that are profiled are named like xyz_alloc() for API access to the function. xyz_alloc() then calls xyz_alloc_noprof() to do the allocation work. The kernel-doc comments for the memory allocation functions are introduced with the xyz_alloc() function names but the function implementations are the xyz_alloc_noprof() names. This causes kernel-doc warnings for mismatched documentation and function prototype names. By dropping the "_noprof" part of the function name, the kernel-doc function name matches the function prototype name, so the warnings are resolved. [1] https://lore.kernel.org/all/20240321163705.3067592-1-surenb@google.com/ Link: https://lkml.kernel.org/r/20240326054149.2121-1-rdunlap@infradead.orgSigned-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/all/20240325123603.1bdd6588@canb.auug.org.au/Tested-by:
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Yosry Ahmed authored
In pcpu_map_pages(), if __pcpu_map_pages() fails on a CPU, we call __pcpu_unmap_pages() to clean up mappings on all CPUs where mappings were created, but not on the CPU where __pcpu_map_pages() fails. __pcpu_map_pages() and __pcpu_unmap_pages() are wrappers around vmap_pages_range_noflush() and vunmap_range_noflush(). All other callers of vmap_pages_range_noflush() call vunmap_range_noflush() when mapping fails, except pcpu_map_pages(). The reason could be that partial mappings may be left behind from a failed mapping attempt. Call __pcpu_unmap_pages() for the failed CPU as well in pcpu_map_pages(). This was found by code inspection, no failures or bugs were observed. Link: https://lkml.kernel.org/r/20240311194346.2291333-1-yosryahmed@google.comSigned-off-by:
Yosry Ahmed <yosryahmed@google.com> Acked-by:
Dennis Zhou <dennis@kernel.org> Cc: Christoph Lameter (Ampere) <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Donet Tom authored
commit bda420b9 ("numa balancing: migrate on fault among multiple bound nodes") added support for migrate on protnone reference with MPOL_BIND memory policy. This allowed numa fault migration when the executing node is part of the policy mask for MPOL_BIND. This patch extends migration support to MPOL_PREFERRED_MANY policy. Currently, we cannot specify MPOL_PREFERRED_MANY with the mempolicy flag MPOL_F_NUMA_BALANCING. This causes issues when we want to use NUMA_BALANCING_MEMORY_TIERING. To effectively use the slow memory tier, the kernel should not allocate pages from the slower memory tier via allocation control zonelist fallback. Instead, we should move cold pages from the faster memory node via memory demotion. For a page allocation, kswapd is only woken up after we try to allocate pages from all nodes in the allocation zone list. This implies that, without using memory policies, we will end up allocating hot pages in the slower memory tier. MPOL_PREFERRED_MANY was added by commit b27abacc ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes") to allow better allocation control when we have memory tiers in the system. With MPOL_PREFERRED_MANY, the user can use a policy node mask consisting only of faster memory nodes. When we fail to allocate pages from the faster memory node, kswapd would be woken up, allowing demotion of cold pages to slower memory nodes. With the current kernel, such usage of memory policies implies we can't do page promotion from a slower memory tier to a faster memory tier using numa fault. This patch fixes this issue. For MPOL_PREFERRED_MANY, if the executing node is in the policy node mask, we allow numa migration to the executing nodes. If the executing node is not in the policy node mask, we do not allow numa migration. Example: On a 2-sockets system, NUMA node N0, N1 and N2 are in socket 0, N3 in socket 1. N0, N1 and N3 have fast memory and CPU, while N2 has slow memory and no CPU. For a workload, we may use MPOL_PREFERRED_MANY with nodemask N0 and N1 set because the workload runs on CPUs of socket 0 at most times. Then, even if the workload runs on CPUs of N3 occasionally, we will not try to migrate the workload pages from N2 to N3 because users may want to avoid cross-socket access as much as possible in the long term. In below table, Process is the Process executing node and Curr Loc Pgs is the numa node where page present(folio node) =========================================================== Process Policy Curr Loc Pgs Observation ----------------------------------------------------------- N0 N0 N1 N1 Pages Migrated from N1 to N0 N0 N0 N1 N2 Pages Migrated from N2 to N0 N0 N0 N1 N3 Pages Migrated from N3 to N0 N3 N0 N1 N0 Pages NOT Migrated to N3 N3 N0 N1 N1 Pages NOT Migrated to N3 N3 N0 N1 N2 Pages NOT Migrated to N3 ------------------------------------------------------------ Link: https://lkml.kernel.org/r/158acc57319129aa46d50fd64c9330f3e7c7b4bf.1711373653.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/369d6a58758396335fd1176d97bbca4e7730d75a.1709909210.git.donettom@linux.ibm.comSigned-off-by:
Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org> Signed-off-by:
Donet Tom <donettom@linux.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Donet Tom authored
Patch series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy:, v4. This patchset is to optimize the cross-socket memory access with MPOL_PREFERRED_MANY policy. To test this patch we ran the following test on a 3 node system. Node 0 - 2GB - Tier 1 Node 1 - 11GB - Tier 1 Node 6 - 10GB - Tier 2 Below changes are made to memcached to set the memory policy, It select Node0 and Node1 as preferred nodes. #include <numaif.h> #include <numa.h> unsigned long nodemask; int ret; nodemask = 0x03; ret = set_mempolicy(MPOL_PREFERRED_MANY | MPOL_F_NUMA_BALANCING, &nodemask, 10); /* If MPOL_F_NUMA_BALANCING isn't supported, * fall back to MPOL_PREFERRED_MANY */ if (ret < 0 && errno == EINVAL){ printf("set mem policy normal\n"); ret = set_mempolicy(MPOL_PREFERRED_MANY, &nodemask, 10); } if (ret < 0) { perror("Failed to call set_mempolicy"); exit(-1); } Test Procedure: =============== 1. Make sure memory tiring and demotion are enabled. 2. Start memcached. # ./memcached -b 100000 -m 204800 -u root -c 1000000 -t 7 -d -s "/tmp/memcached.sock" 3. Run memtier_benchmark to store 3200000 keys. #./memtier_benchmark -S "/tmp/memcached.sock" --protocol=memcache_binary --threads=1 --pipeline=1 --ratio=1:0 --key-pattern=S:S --key-minimum=1 --key-maximum=3200000 -n allkeys -c 1 -R -x 1 -d 1024 4. Start a memory eater on node 0 and 1. This will demote all memcached pages to node 6. 5. Make sure all the memcached pages got demoted to lower tier by reading /proc/<memcaced PID>/numa_maps. # cat /proc/2771/numa_maps --- default anon=1009 dirty=1009 active=0 N6=1009 kernelpagesize_kB=64 default anon=1009 dirty=1009 active=0 N6=1009 kernelpagesize_kB=64 --- 6. Kill memory eater. 7. Read the pgpromote_success counter. 8. Start reading the keys by running memtier_benchmark. #./memtier_benchmark -S "/tmp/memcached.sock" --protocol=memcache_binary --pipeline=1 --distinct-client-seed --ratio=0:3 --key-pattern=R:R --key-minimum=1 --key-maximum=3200000 -n allkeys --threads=64 -c 1 -R -x 6 9. Read the pgpromote_success counter. Test Results: ============= Without Patch ------------------ 1. pgpromote_success before test Node 0: pgpromote_success 11 Node 1: pgpromote_success 140974 pgpromote_success after test Node 0: pgpromote_success 11 Node 1: pgpromote_success 140974 2. Memtier-benchmark result. AGGREGATED AVERAGE RESULTS (6 runs) ================================================================== Type Ops/sec Hits/sec Misses/sec Avg. Latency p50 Latency ------------------------------------------------------------------ Sets 0.00 --- --- --- --- Gets 305792.03 305791.93 0.10 0.18949 0.16700 Waits 0.00 --- --- --- --- Totals 305792.03 305791.93 0.10 0.18949 0.16700 ====================================== p99 Latency p99.9 Latency KB/sec ------------------------------------- --- --- 0.00 0.44700 1.71100 11542.69 --- --- --- 0.44700 1.71100 11542.69 With Patch --------------- 1. pgpromote_success before test Node 0: pgpromote_success 5 Node 1: pgpromote_success 89386 pgpromote_success after test Node 0: pgpromote_success 57895 Node 1: pgpromote_success 141463 2. Memtier-benchmark result. AGGREGATED AVERAGE RESULTS (6 runs) ==================================================================== Type Ops/sec Hits/sec Misses/sec Avg. Latency p50 Latency -------------------------------------------------------------------- Sets 0.00 --- --- --- --- Gets 521942.24 521942.07 0.17 0.11459 0.10300 Waits 0.00 --- --- --- --- Totals 521942.24 521942.07 0.17 0.11459 0.10300 ======================================= p99 Latency p99.9 Latency KB/sec --------------------------------------- --- --- 0.00 0.23100 0.31900 19701.68 --- --- --- 0.23100 0.31900 19701.68 Test Result Analysis: ===================== 1. With patch we could observe pages are getting promoted. 2. Memtier-benchmark results shows that, with the patch, performance has increased more than 50%. Ops/sec without fix - 305792.03 Ops/sec with fix - 521942.24 This patch (of 2): Instead of using 'cpu_to_node()', we use 'numa_node_id()', which is quicker. smp_processor_id is guaranteed to be stable in the 'mpol_misplaced()' function because it is called with ptl held. lockdep_assert_held was added to ensure that. No functional change in this patch. [donettom@linux.ibm.com: add "* @vmf: structure describing the fault" comment] Link: https://lkml.kernel.org/r/d8b993ea9dccfac0bc3ed61d3a81f4ac5f376e46.1711002865.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/cover.1711373653.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/6059f034f436734b472d066db69676fb3a459864.1711373653.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/cover.1709909210.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/744646531af02cc687cde8ae788fb1779e99d02c.1709909210.git.donettom@linux.ibm.comSigned-off-by: -
Yosry Ahmed authored
zswap_find_zpool() checks if ZSWAP_NR_ZPOOLS > 1, which is always true. This is a remnant from a patch version that had ZSWAP_NR_ZPOOLS as a config option and never made it upstream. Remove the unnecessary check. Link: https://lkml.kernel.org/r/20240311235210.2937484-1-yosryahmed@google.comSigned-off-by:
Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by:
Nhat Pham <nphamcs@gmail.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Duoming Zhou authored
The kcalloc() in dmirror_device_evict_chunk() will return null if the physical memory has run out. As a result, if src_pfns or dst_pfns is dereferenced, the null pointer dereference bug will happen. Moreover, the device is going away. If the kcalloc() fails, the pages mapping a chunk could not be evicted. So add a __GFP_NOFAIL flag in kcalloc(). Finally, as there is no need to have physically contiguous memory, Switch kcalloc() to kvcalloc() in order to avoid failing allocations. Link: https://lkml.kernel.org/r/20240312005905.9939-1-duoming@zju.edu.cn Fixes: b2ef9f5a ("mm/hmm/test: add selftest driver for HMM") Signed-off-by:
Duoming Zhou <duoming@zju.edu.cn> Cc: Jérôme Glisse <jglisse@redhat.com> Signed-off-by:
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