kernel/mm/damon, branch linux-6.10.y

mm/damon/vaddr: protect vma traversal in __damon_va_thre_regions() with rcu read lock

2024-10-04T14:33:49Z

commit fb497d6db7c19c797cbd694b52d1af87c4eebcc6 upstream. Traversing VMAs of a given maple tree should be protected by rcu read lock. However, __damon_va_three_regions() is not doing the protection. Hold the lock. Link: https://lkml.kernel.org/r/20240905001204.1481-1-sj@kernel.org Fixes: d0cf3dd47f0d ("damon: convert __damon_va_three_regions to use the VMA iterator") Signed-off-by: Liam R. Howlett Signed-off-by: SeongJae Park Reported-by: Guenter Roeck Closes: https://lore.kernel.org/b83651a0-5b24-4206-b860-cb54ffdf209b@roeck-us.net Tested-by: Guenter Roeck Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm/damon/core: merge regions aggressively when max_nr_regions is unmet

2024-07-04T05:40:36Z

DAMON keeps the number of regions under max_nr_regions by skipping regions split operations when doing so can make the number higher than the limit. It works well for preventing violation of the limit. But, if somehow the violation happens, it cannot recovery well depending on the situation. In detail, if the real number of regions having different access pattern is higher than the limit, the mechanism cannot reduce the number below the limit. In such a case, the system could suffer from high monitoring overhead of DAMON. The violation can actually happen. For an example, the user could reduce max_nr_regions while DAMON is running, to be lower than the current number of regions. Fix the problem by repeating the merge operations with increasing aggressiveness in kdamond_merge_regions() for the case, until the limit is met. [sj@kernel.org: increase regions merge aggressiveness while respecting min_nr_regions] Link: https://lkml.kernel.org/r/20240626164753.46270-1-sj@kernel.org [sj@kernel.org: ensure max threshold attempt for max_nr_regions violation] Link: https://lkml.kernel.org/r/20240627163153.75969-1-sj@kernel.org Link: https://lkml.kernel.org/r/20240624175814.89611-1-sj@kernel.org Fixes: b9a6ac4e4ede ("mm/damon: adaptively adjust regions") Signed-off-by: SeongJae Park Cc: [5.15+] Signed-off-by: Andrew Morton

mm/damon/core: fix return value from damos_wmark_metric_value

2024-05-11T22:41:36Z

damos_wmark_metric_value's return value is 'unsigned long', so returning -EINVAL as 'unsigned long' may turn out to be very different from the expected one (using 2's complement) and treat as usual matric's value. So, fix that, checking if returned value is not 0. Link: https://lkml.kernel.org/r/20240506180238.53842-1-sj@kernel.org Fixes: ee801b7dd782 ("mm/damon/schemes: activate schemes based on a watermarks mechanism") Signed-off-by: Alex Rusuf Reviewed-by: SeongJae Park Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()

2024-05-11T22:41:33Z

Patch series "mm/damon: misc fixes and improvements". Add miscelleneous and non-urgent fixes and improvements for DAMON code, selftests, and documents. This patch (of 10): damos_quota_init_priv() function should initialize all private fields of struct damos_quota. However, it is not initializing ->esz_bp field. This could result in use of uninitialized variable from damon_feed_loop_next_input() function. There is no such issue at the moment because every caller of the function is passing damos_quota object that already having the field zero value. But we cannot guarantee the future, and the function is not doing what it is promising. A bug is a bug. This fix is for preventing possible future issues. Link: https://lkml.kernel.org/r/20240503180318.72798-1-sj@kernel.org Link: https://lkml.kernel.org/r/20240503180318.72798-2-sj@kernel.org Fixes: 9294a037c015 ("mm/damon/core: implement goal-oriented feedback-driven quota auto-tuning") Signed-off-by: SeongJae Park Cc: Jonathan Corbet Cc: Shuah Khan Signed-off-by: Andrew Morton

mm/vmscan: remove ignore_references argument of reclaim_pages()

2024-05-07T17:37:02Z

All reclaim_pages() callers are setting 'ignore_references' parameter 'true'. In other words, the parameter is not really being used. Remove the argument to make it simple. Link: https://lkml.kernel.org/r/20240429224451.67081-4-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

mm/damon/paddr: do page level access check for pageout DAMOS action on its own

2024-05-07T17:37:01Z

'pageout' DAMOS action implementation of 'paddr' DAMON operations set asks reclaim_pages() to do page level access check if the user is not asking DAMOS to do that on its own. Simplify the logic by making the check always be done by 'paddr'. Link: https://lkml.kernel.org/r/20240429224451.67081-3-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

mm/damon/paddr: avoid unnecessary page level access check for pageout DAMOS action

2024-05-07T17:37:01Z

Patch series "mm/damon/paddr: simplify page level access re-check for pageout. The 'pageout' DAMOS action implementation of 'paddr' asks reclaim_pages() to do page level access check again. But the user can ask 'paddr' to do the page level access check on its own, using DAMOS filter of 'young page' type. Meanwhile, 'paddr' is the only user of reclaim_pages() that asks the page level access check. Make 'paddr' does the page level access check on its own always, and simplify reclaim_pages() by removing the page level access check request handling logic. As a result of the change for reclaim_pages(), reclaim_folio_list(), which is called by reclaim_pages(), also no more need to do the page level access check. Simplify the function, too. This patch (of 4): 'pageout' DAMOS action implementation of 'paddr' asks reclaim_pages() to do the page level access check. User could ask DAMOS to do the page level access check on its own using 'young page' type DAMOS filter. In the case, pageout DAMOS action unnecessarily asks reclaim_pages() to do the check again. Ask the page level access check only if the scheme is not having the filter. Link: https://lkml.kernel.org/r/20240429224451.67081-1-sj@kernel.org Link: https://lkml.kernel.org/r/20240429224451.67081-2-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

mm/damon/paddr: implement DAMOS filter type YOUNG

2024-05-06T00:53:55Z

DAMOS filter of type YOUNG is defined, but not yet implemented by any DAMON operations set. Add the implementation on 'paddr', the DAMON operations set for the physical address space. Link: https://lkml.kernel.org/r/20240426195247.100306-5-sj@kernel.org Signed-off-by: SeongJae Park Tested-by: Honggyu Kim Cc: Jonathan Corbet Signed-off-by: Andrew Morton

mm/damon: add DAMOS filter type YOUNG

2024-05-06T00:53:55Z

Define yet another DAMOS filter type, YOUNG. Like anon and memcg, the type of filter will be applied to each page in the memory region, and see if the page is accessed since the last check. Based on the 'matching' parameter, the page is filtered out or in. Note that this commit is adding only the type definition. The implementation should be made by DAMON operations sets. A commit for the implementation on 'paddr' DAMON operations set will follow. Link: https://lkml.kernel.org/r/20240426195247.100306-4-sj@kernel.org Signed-off-by: SeongJae Park Tested-by: Honggyu Kim Cc: Jonathan Corbet Signed-off-by: Andrew Morton

mm/damon/paddr: implement damon_folio_mkold()

2024-05-06T00:53:54Z

damon_pa_mkold() receives physical address, get the folio covering the address, and makes the folio as old. A following commit will reuse the internal logic for marking a given folio as old. To avoid duplication of the code, split the internal logic. Also, change the rmap walker function's name from __damon_pa_mkold() to damon_folio_mkold_one(), following the change of the caller's name and the naming rule that more commonly used by other rmap walkers. Link: https://lkml.kernel.org/r/20240426195247.100306-3-sj@kernel.org Signed-off-by: SeongJae Park Tested-by: Honggyu Kim Cc: Jonathan Corbet Signed-off-by: Andrew Morton