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This reverts commit5da226dbfc("mm: skip CMA pages when they are not available") andb7108d6631("Multi-gen LRU: skip CMA pages when they are not eligible"). lruvec->lru_lock is highly contended and is held when calling isolate_lru_folios. If the lru has a large number of CMA folios consecutively, while the allocation type requested is not MIGRATE_MOVABLE, isolate_lru_folios can hold the lock for a very long time while it skips those. For FIO workload, ~150million order=0 folios were skipped to isolate a few ZONE_DMA folios [1]. This can cause lockups [1] and high memory pressure for extended periods of time [2]. Remove skipping CMA for MGLRU as well, as it was introduced in sort_folio for the same resaon as5da226dbfc. [1] https://lore.kernel.org/all/CAOUHufbkhMZYz20aM_3rHZ3OcK4m2puji2FGpUpn_-DevGk3Kg@mail.gmail.com/ [2] https://lore.kernel.org/all/ZrssOrcJIDy8hacI@gmail.com/ [usamaarif642@gmail.com: also revertb7108d6631, per Johannes] Link: https://lkml.kernel.org/r/9060a32d-b2d7-48c0-8626-1db535653c54@gmail.com Link: https://lkml.kernel.org/r/357ac325-4c61-497a-92a3-bdbd230d5ec9@gmail.com Link: https://lkml.kernel.org/r/9060a32d-b2d7-48c0-8626-1db535653c54@gmail.com Fixes:5da226dbfc("mm: skip CMA pages when they are not available") Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Bharata B Rao <bharata@amd.com> Cc: Breno Leitao <leitao@debian.org> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yu Zhao <yuzhao@google.com> Cc: Zhaoyang Huang <huangzhaoyang@gmail.com> Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
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In order to build the documentation, use ``make htmldocs`` or
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Please read the Documentation/process/changes.rst file, as it contains the
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