- 04 Jul, 2022 40 commits
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Sergey Senozhatsky authored
Always use crypto_has_comp() so that crypto can lookup module, call usermodhelper to load the modules, wait for usermodhelper to finish and so on. Otherwise crypto will do all of these steps under CPU hot-plug lock and this looks like too much stuff to handle under the CPU hot-plug lock. Besides this can end up in a deadlock when usermodhelper triggers a code path that attempts to lock the CPU hot-plug lock, that zram already holds. An example of such deadlock: - path A. zram grabs CPU hot-plug lock, execs /sbin/modprobe from crypto and waits for modprobe to finish disksize_store zcomp_create __cpuhp_state_add_instance __cpuhp_state_add_instance_cpuslocked zcomp_cpu_up_prepare crypto_alloc_base crypto_alg_mod_lookup call_usermodehelper_exec wait_for_completion_killable do_wait_for_common schedule - path B. async work kthread that brings in scsi device. It wants to register CPUHP states at some point, and it needs the CPU hot-plug lock for that, which is owned by zram. async_run_entry_fn scsi_probe_and_add_lun scsi_mq_alloc_queue blk_mq_init_queue blk_mq_init_allocated_queue blk_mq_realloc_hw_ctxs __cpuhp_state_add_instance __cpuhp_state_add_instance_cpuslocked mutex_lock schedule - path C. modprobe sleeps, waiting for all aync works to finish. load_module do_init_module async_synchronize_full async_synchronize_cookie_domain schedule [senozhatsky@chromium.org: add comment] Link: https://lkml.kernel.org/r/20220624060606.1014474-1-senozhatsky@chromium.org Link: https://lkml.kernel.org/r/20220622023501.517125-1-senozhatsky@chromium.orgSigned-off-by:Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Yun-Ze Li authored
Comments that mention mem_hotplug_end() are confusing as there is no function called mem_hotplug_end(). Fix them by replacing all the occurences of mem_hotplug_end() in the comments with mem_hotplug_done(). [akpm@linux-foundation.org: grammatical fixes] Link: https://lkml.kernel.org/r/20220620071516.1286101-1-p76091292@gs.ncku.edu.twSigned-off-by:
Yun-Ze Li <p76091292@gs.ncku.edu.tw> Cc: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by:
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Vincent Whitchurch authored
Pss is the sum of the sizes of clean and dirty private pages, and the proportional sizes of clean and dirty shared pages: Private = Private_Dirty + Private_Clean Shared_Proportional = Shared_Dirty_Proportional + Shared_Clean_Proportional Pss = Private + Shared_Proportional The Shared*Proportional fields are not present in smaps, so it is not always possible to determine how much of the Pss is from dirty pages and how much is from clean pages. This information can be useful for measuring memory usage for the purpose of optimisation, since clean pages can usually be discarded by the kernel immediately while dirty pages cannot. The smaps routines in the kernel already have access to this data, so add a Pss_Dirty to show it to userspace. Pss_Clean is not added since it can be calculated from Pss and Pss_Dirty. Link: https://lkml.kernel.org/r/20220620081251.2928103-1-vincent.whitchurch@axis.comSigned-off-by:
Vincent Whitchurch <vincent.whitchurch@axis.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Baolin Wang authored
According to previous discussion [1], there are so many levels of indenting to handle the hugetlb case when unmapping or migration. We can combine folio_test_anon() and huge_pmd_unshare() to save one level of indenting, by adding a local variable and moving the VM_BUG_ON() a little forward. No intended functional changes in this patch. [1] https://lore.kernel.org/all/0b986dc4-5843-3e2d-c2df-5a2e9f13e6ab@oracle.com/ Link: https://lkml.kernel.org/r/28414b1b96f095e838c1e548074f8e0fc70d78cf.1655724713.git.baolin.wang@linux.alibaba.comSigned-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Miaohe Lin authored
Passing index to pte_offset_map_lock() directly so the below calculation can be avoided. Rename orig_pte to ptep as it's not changed. Also use helper is_swap_pte() to improve the readability. No functional change intended. [akpm@linux-foundation.org: reduce scope of `ptep'] Link: https://lkml.kernel.org/r/20220618090527.37843-1-linmiaohe@huawei.comSigned-off-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Muchun Song authored
commit 641844f5 ("mm/hugetlb: introduce minimum hugepage order") fixed a static checker warning and introduced a global variable minimum_order to fix the warning. However, the local variable in dissolve_free_huge_pages() can be initialized to huge_page_order(&default_hstate) to fix the warning. So remove minimum_order to simplify the code. Link: https://lkml.kernel.org/r/20220616033846.96937-1-songmuchun@bytedance.comSigned-off-by:
Muchun Song <songmuchun@bytedance.com> Reviewed-by:
Oscar Salvador <osalvador@suse.de> Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Muchun Song authored
For now, the feature of hugetlb_free_vmemmap is not compatible with the feature of memory_hotplug.memmap_on_memory, and hugetlb_free_vmemmap takes precedence over memory_hotplug.memmap_on_memory. However, someone wants to make memory_hotplug.memmap_on_memory takes precedence over hugetlb_free_vmemmap since memmap_on_memory makes it more likely to succeed memory hotplug in close-to-OOM situations. So the decision of making hugetlb_free_vmemmap take precedence is not wise and elegant. The proper approach is to have hugetlb_vmemmap.c do the check whether the section which the HugeTLB pages belong to can be optimized. If the section's vmemmap pages are allocated from the added memory block itself, hugetlb_free_vmemmap should refuse to optimize the vmemmap, otherwise, do the optimization. Then both kernel parameters are compatible. So this patch introduces VmemmapSelfHosted to mask any non-optimizable vmemmap pages. The hugetlb_vmemmap can use this flag to detect if a vmemmap page can be optimized. [songmuchun@bytedance.com: walk vmemmap page tables to avoid false-positive] Link: https://lkml.kernel.org/r/20220620110616.12056-3-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-3-songmuchun@bytedance.comSigned-off-by:
David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by:
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Muchun Song authored
Patch series "make hugetlb_optimize_vmemmap compatible with memmap_on_memory", v3. This series makes hugetlb_optimize_vmemmap compatible with memmap_on_memory. This patch (of 2): We are almost running out of section flags, only one bit is available in the worst case (powerpc with 256k pages). However, there are still some free bits (in ->section_mem_map) on other architectures (e.g. x86_64 has 10 bits available, arm64 has 8 bits available with worst case of 64K pages). We have hard coded those numbers in code, it is inconvenient to use those bits on other architectures except powerpc. So transfer those section flags to enumeration to make it easy to add new section flags in the future. Also, move SECTION_TAINT_ZONE_DEVICE into the scope of CONFIG_ZONE_DEVICE to save a bit on non-zone-device case. [songmuchun@bytedance.com: replace enum with defines per David] Link: https://lkml.kernel.org/r/20220620110616.12056-2-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-1-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-2-songmuchun@bytedance.comSigned-off-by:
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Matthew Wilcox (Oracle) authored
All callers now have a folio, so convert the entire function to operate on folios. Link: https://lkml.kernel.org/r/20220617175020.717127-23-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
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Matthew Wilcox (Oracle) authored
All but one caller already has a folio, so convert it to use a folio. Link: https://lkml.kernel.org/r/20220617175020.717127-22-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
The only caller already has a folio, so push the folio->page conversion down a level. Link: https://lkml.kernel.org/r/20220617175020.717127-21-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
All callers now have a folio, so push the folio->page conversion down to this function. [akpm@linux-foundation.org: uninline destroy_large_folio() to fix build issue] Link: https://lkml.kernel.org/r/20220617175020.717127-20-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
All the callers now have a folio. Saves several calls to compound_head, totalling 502 bytes of text. Link: https://lkml.kernel.org/r/20220617175020.717127-19-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
All the callers now have a folio, so pass it in. This doesn't save any text, but it does save a call to compound_head() as folio_test_hugetlb() does not contain a call like PageHuge() does. Link: https://lkml.kernel.org/r/20220617175020.717127-18-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Saves 56 bytes of text by removing a call to compound_head(). Link: https://lkml.kernel.org/r/20220617175020.717127-17-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Saves 11 bytes of text by removing a check of PageTail. Link: https://lkml.kernel.org/r/20220617175020.717127-16-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Pages linked through the LRU list cannot be tail pages as ->compound_head is in a union with one of the words of the list_head, and they cannot be ZONE_DEVICE pages as ->pgmap is in a union with the same word. Saves 60 bytes of text by removing a call to page_is_fake_head(). Link: https://lkml.kernel.org/r/20220617175020.717127-15-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
This function was already calling compound_head(), but now it can cache the result of calling compound_head() and avoid calling it again. Saves 299 bytes of text by avoiding various calls to compound_page() and avoiding checks of PageTail. Link: https://lkml.kernel.org/r/20220617175020.717127-14-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Save a few calls to compound_head by converting the passed page to a folio. Reduces kernel text size by 74 bytes. Link: https://lkml.kernel.org/r/20220617175020.717127-13-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Do the per-cpu dereferencing of the fbatches once which saves 14 bytes of text and several percpu relocations. Link: https://lkml.kernel.org/r/20220617175020.717127-12-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
The function is too long, so pull this complicated conditional out into cpu_needs_drain(). This ends up shrinking the text by 14 bytes, by allowing GCC to cache the result of calling per_cpu() instead of relocating each lookup individually. Link: https://lkml.kernel.org/r/20220617175020.717127-11-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
No change to generated code, but this struct no longer contains any pagevecs, and not all the folio batches it contains are lru. Link: https://lkml.kernel.org/r/20220617175020.717127-10-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Rename it to just 'activate', saving 696 bytes of text from removals of compound_page() and the pagevec_lru_move_fn() infrastructure. Inline need_activate_page_drain() into its only caller. Link: https://lkml.kernel.org/r/20220617175020.717127-9-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Using folios instead of pages removes several calls to compound_head(), shrinking the kernel by 1089 bytes of text. Link: https://lkml.kernel.org/r/20220617175020.717127-8-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Using folios instead of pages shrinks deactivate_page() and lru_deactivate_fn() by 778 bytes between them. Link: https://lkml.kernel.org/r/20220617175020.717127-7-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Use a folio throughout lru_deactivate_file_fn(), removing many hidden calls to compound_head(). Shrinks the kernel by 864 bytes of text. Link: https://lkml.kernel.org/r/20220617175020.717127-6-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
When adding folios to the LRU for the first time, the LRU flag will already be clear, so skip the test-and-clear part of moving from one LRU to another. Removes 285 bytes from kernel text, mostly due to removing __pagevec_lru_add(). Link: https://lkml.kernel.org/r/20220617175020.717127-5-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
__pagevec_lru_add has no callers outside swap.c, so make it static, and move it to a more logical position in the file. Link: https://lkml.kernel.org/r/20220617175020.717127-4-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Start converting the LRU from pagevecs to folio_batches. Combine the functionality of pagevec_add_and_need_flush() with pagevec_lru_move_fn() in the new folio_batch_add_and_move(). Convert the lru_rotate pagevec to a folio_batch. Adds 223 bytes total to kernel text, because we're duplicating infrastructure. This will be more than made up for in future patches. Link: https://lkml.kernel.org/r/20220617175020.717127-3-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Patch series "Convert the swap code to be more folio-based". There's still more to do with the swap code, but this reaps a lot of the folio benefit. More than 4kB of kernel text saved (with the UEK7 kernel config). I don't know how much that's going to translate into CPU savings, but some of those compound_head() calls are on every page free, so it should be noticable. It might even be noticable just from an I-cache consumption perspective. This patch (of 22): This is just a wrapper around release_pages() for now. Place the prototype in mm.h along with folio_put() and folio_put_refs(). Link: https://lkml.kernel.org/r/20220617175020.717127-1-willy@infradead.org Link: https://lkml.kernel.org/r/20220617175020.717127-2-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Remove a few hidden calls to compound_head, saving 76 bytes of text. Link: https://lkml.kernel.org/r/20220617154248.700416-6-willy@infradead.orgSigned-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Matthew Wilcox (Oracle) authored
Remove a few hidden calls to compound_head, saving 411 bytes of text. Link: https://lkml.kernel.org/r/20220617154248.700416-5-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Remove a few hidden calls to compound_head, saving 387 bytes of text on my test configuration. Link: https://lkml.kernel.org/r/20220617154248.700416-4-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Remove a few hidden calls to compound_head, saving 279 bytes of text. Link: https://lkml.kernel.org/r/20220617154248.700416-3-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Patch series "nvert much of vmscan to folios" vmscan always operates on folios since it puts the pages on the LRU list. Switching all of these functions from pages to folios saves 1483 bytes of text from removing all the baggage around calling compound_page() and similar functions. This patch (of 5): This is a straightforward conversion which removes several hidden calls to compound_head, saving 330 bytes of kernel text. Link: https://lkml.kernel.org/r/20220617154248.700416-1-willy@infradead.org Link: https://lkml.kernel.org/r/20220617154248.700416-2-willy@infradead.orgSigned-off-by:
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David Hildenbrand authored
Similar to our MM_CP_DIRTY_ACCT handling for shared, writable mappings, we can try mapping anonymous pages in a private writable mapping writable if they are exclusive, the PTE is already dirty, and no special handling applies. Mapping the anonymous page writable is essentially the same thing the write fault handler would do in this case. Special handling is required for uffd-wp and softdirty tracking, so take care of that properly. Also, leave PROT_NONE handling alone for now; in the future, we could similarly extend the logic in do_numa_page() or use pte_mk_savedwrite() here. While this improves mprotect(PROT_READ)+mprotect(PROT_READ|PROT_WRITE) performance, it should also be a valuable optimization for uffd-wp, when un-protecting. This has been previously suggested by Peter Collingbourne in [1], relevant in the context of the Scudo memory allocator, before we had PageAnonExclusive. This commit doesn't add the same handling for PMDs (i.e., anonymous THP, anonymous hugetlb); benchmark results from Andrea indicate that there are minor performance gains, so it's might still be valuable to streamline that logic for all anonymous pages in the future. As we now also set MM_CP_DIRTY_ACCT for private mappings, let's rename it to MM_CP_TRY_CHANGE_WRITABLE, to make it clearer what's actually happening. Micro-benchmark courtesy of Andrea: === #define _GNU_SOURCE #include <sys/mman.h> #include <stdlib.h> #include <string.h> #include <stdio.h> #include <unistd.h> #define SIZE (1024*1024*1024) int main(int argc, char *argv[]) { char *p; if (posix_memalign((void **)&p, sysconf(_SC_PAGESIZE)*512, SIZE)) perror("posix_memalign"), exit(1); if (madvise(p, SIZE, argc > 1 ? MADV_HUGEPAGE : MADV_NOHUGEPAGE)) perror("madvise"); explicit_bzero(p, SIZE); for (int loops = 0; loops < 40; loops++) { if (mprotect(p, SIZE, PROT_READ)) perror("mprotect"), exit(1); if (mprotect(p, SIZE, PROT_READ|PROT_WRITE)) perror("mprotect"), exit(1); explicit_bzero(p, SIZE); } } === Results on my Ryzen 9 3900X: Stock 10 runs (lower is better): AVG 6.398s, STDEV 0.043 Patched 10 runs (lower is better): AVG 3.780s, STDEV 0.026 === [1] https://lkml.kernel.org/r/20210429214801.2583336-1-pcc@google.com Link: https://lkml.kernel.org/r/20220614093629.76309-1-david@redhat.comSigned-off-by:Peter Collingbourne <pcc@google.com> Acked-by:
Peter Xu <peterx@redhat.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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Edward Liaw authored
On Android this test is getting stuck in an infinite loop due to indeterminate behavior: The local variables steps and signalled were being reset to 1 and 0 respectively after every jump back to sigsetjmp by siglongjmp in the signal handler. The test was incrementing them and expecting them to retain their incremented values. The documentation for siglongjmp says: All accessible objects have values as of the time sigsetjmp() was called, except that the values of objects of automatic storage duration which are local to the function containing the invocation of the corresponding sigsetjmp() which do not have volatile-qualified type and which are changed between the sigsetjmp() invocation and siglongjmp() call are indeterminate. Tagging steps and signalled with volatile enabled the test to pass. Link: https://lkml.kernel.org/r/20220613233321.431282-1-edliaw@google.comSigned-off-by:
Edward Liaw <edliaw@google.com> Reviewed-by:
Axel Rasmussen <axelrasmussen@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by:
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SeongJae Park authored
This commit documents the usage of DAMON_LRU_SORT for admins. Link: https://lkml.kernel.org/r/20220613192301.8817-10-sj@kernel.orgSigned-off-by:
SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by:
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SeongJae Park authored
Users can do data access-aware LRU-lists sorting using 'LRU_PRIO' and 'LRU_DEPRIO' DAMOS actions. However, finding best parameters including the hotness/coldness thresholds, CPU quota, and watermarks could be challenging for some users. To make the scheme easy to be used without complex tuning for common situations, this commit implements a static kernel module called 'DAMON_LRU_SORT' using the 'LRU_PRIO' and 'LRU_DEPRIO' DAMOS actions. It proactively sorts LRU-lists using DAMON with conservatively chosen default values of the parameters. That is, the module under its default parameters will make no harm for common situations but provide some level of efficiency improvements for systems having clear hot/cold access pattern under a level of memory pressure while consuming only a limited small portion of CPU time. Link: https://lkml.kernel.org/r/20220613192301.8817-9-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit documents the 'LRU_DEPRIO' scheme action for DAMON sysfs interface.` Link: https://lkml.kernel.org/r/20220613192301.8817-8-sj@kernel.orgSigned-off-by:
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