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2023-09-19mm: page_alloc: fix CMA and HIGHATOMIC landing on the wrong buddy listJohannes Weiner1-6/+6
Commit 4b23a68f9536 ("mm/page_alloc: protect PCP lists with a spinlock") bypasses the pcplist on lock contention and returns the page directly to the buddy list of the page's migratetype. For pages that don't have their own pcplist, such as CMA and HIGHATOMIC, the migratetype is temporarily updated such that the page can hitch a ride on the MOVABLE pcplist. Their true type is later reassessed when flushing in free_pcppages_bulk(). However, when lock contention is detected after the type was already overridden, the bypass will then put the page on the wrong buddy list. Once on the MOVABLE buddy list, the page becomes eligible for fallbacks and even stealing. In the case of HIGHATOMIC, otherwise ineligible allocations can dip into the highatomic reserves. In the case of CMA, the page can be lost from the CMA region permanently. Use a separate pcpmigratetype variable for the pcplist override. Use the original migratetype when going directly to the buddy. This fixes the bug and should make the intentions more obvious in the code. Originally sent here to address the HIGHATOMIC case: https://lore.kernel.org/lkml/20230821183733.106619-4-hannes@cmpxchg.org/ Changelog updated in response to the CMA-specific bug report. [mgorman@techsingularity.net: updated changelog] Link: https://lkml.kernel.org/r/20230911181108.GA104295@cmpxchg.org Fixes: 4b23a68f9536 ("mm/page_alloc: protect PCP lists with a spinlock") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Joe Liu <joe.liu@mediatek.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-03mm: page_alloc: remove stale CMA guard codeJohannes Weiner1-17/+4
In the past, movable allocations could be disallowed from CMA through PF_MEMALLOC_PIN. As CMA pages are funneled through the MOVABLE pcplist, this required filtering that cornercase during allocations, such that pinnable allocations wouldn't accidentally get a CMA page. However, since 8e3560d963d2 ("mm: honor PF_MEMALLOC_PIN for all movable pages"), PF_MEMALLOC_PIN automatically excludes __GFP_MOVABLE. Once again, MOVABLE implies CMA is allowed. Remove the stale filtering code. Also remove a stale comment that was introduced as part of the filtering code, because the filtering let order-0 pages fall through to the buddy allocator. See 1d91df85f399 ("mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore} APIs") for context. The comment's been obsolete since the introduction of the explicit ALLOC_HIGHATOMIC flag in eb2e2b425c69 ("mm/page_alloc: explicitly record high-order atomic allocations in alloc_flags"). Link: https://lkml.kernel.org/r/20230824153821.243148-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: add large_rmappable page flagMatthew Wilcox (Oracle)1-6/+1
Stored in the first tail page's flags, this flag replaces the destructor. That removes the last of the destructors, so remove all references to folio_dtor and compound_dtor. Link: https://lkml.kernel.org/r/20230816151201.3655946-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: remove HUGETLB_PAGE_DTORMatthew Wilcox (Oracle)1-1/+1
We can use a bit in page[1].flags to indicate that this folio belongs to hugetlb instead of using a value in page[1].dtors. That lets folio_test_hugetlb() become an inline function like it should be. We can also get rid of NULL_COMPOUND_DTOR. Link: https://lkml.kernel.org/r/20230816151201.3655946-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: remove free_compound_page() and the compound_page_dtors arrayMatthew Wilcox (Oracle)1-19/+5
The only remaining destructor is free_compound_page(). Inline it into destroy_large_folio() and remove the array it used to live in. Link: https://lkml.kernel.org/r/20230816151201.3655946-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: convert prep_transhuge_page() to folio_prep_large_rmappable()Matthew Wilcox (Oracle)1-3/+4
Match folio_undo_large_rmappable(), and move the casting from page to folio into the callers (which they were largely doing anyway). Link: https://lkml.kernel.org/r/20230816151201.3655946-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: convert free_transhuge_folio() to folio_undo_large_rmappable()Matthew Wilcox (Oracle)1-3/+6
Indirect calls are expensive, thanks to Spectre. Test for TRANSHUGE_PAGE_DTOR and destroy the folio appropriately. Move the free_compound_page() call into destroy_large_folio() to simplify later patches. Link: https://lkml.kernel.org/r/20230816151201.3655946-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: convert free_huge_page() to free_huge_folio()Matthew Wilcox (Oracle)1-1/+1
Pass a folio instead of the head page to save a few instructions. Update the documentation, at least in English. Link: https://lkml.kernel.org/r/20230816151201.3655946-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-22mm: call free_huge_page() directlyMatthew Wilcox (Oracle)1-3/+5
Indirect calls are expensive, thanks to Spectre. Call free_huge_page() directly if the folio belongs to hugetlb. Link: https://lkml.kernel.org/r/20230816151201.3655946-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_alloc: use get_pfnblock_migratetype to avoid extra page_to_pfnKemeng Shi1-2/+2
We have get_pageblock_migratetype and get_pfnblock_migratetype to get migratetype of page. get_pfnblock_migratetype accepts both page and pfn from caller while get_pageblock_migratetype only accept page and get pfn with page_to_pfn from page. In case we already record pfn of page, we can simply call get_pfnblock_migratetype to avoid a page_to_pfn. Link: https://lkml.kernel.org/r/20230811115945.3423894-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_alloc: remove unnecessary inner __get_pfnblock_flags_maskKemeng Shi1-19/+11
Patch series "Two minor cleanups for get pageblock migratetype". This series contains two minor cleanups for get pageblock migratetype. More details can be found in respective patches. This patch (of 2): get_pfnblock_flags_mask() just calls inline inner __get_pfnblock_flags_mask without any extra work. Just opencode __get_pfnblock_flags_mask in get_pfnblock_flags_mask and replace call to __get_pfnblock_flags_mask with call to get_pfnblock_flags_mask to remove unnecessary __get_pfnblock_flags_mask. Link: https://lkml.kernel.org/r/20230811115945.3423894-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230811115945.3423894-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm: page_alloc: remove unused parameter from reserve_highatomic_pageblock()ZhangPeng1-3/+2
Just remove the redundant parameter alloc_order from reserve_highatomic_pageblock(). No functional modification involved. Link: https://lkml.kernel.org/r/20230809073323.1065286-1-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_alloc: remove unnecessary parameter batch of nr_pcp_freeKemeng Shi1-5/+3
We get batch from pcp and just pass it to nr_pcp_free immediately. Get batch from pcp inside nr_pcp_free to remove unnecessary parameter batch. Link: https://lkml.kernel.org/r/20230809100754.3094517-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_alloc: remove track of active PCP lists range in bulk freeKemeng Shi1-12/+3
Patch series "Two minor cleanups for pcp list in page_alloc". There are two minor cleanups for pcp list in page_alloc. More details can be found in respective patches. This patch (of 2): After commit fd56eef258a17 ("mm/page_alloc: simplify how many pages are selected per pcp list during bulk free"), we will drain all pages in selected pcp list. And we ensured passed count is < pcp->count. Then, the search will finish before wrap-around and track of active PCP lists range intended for wrap-around case is no longer needed. Link: https://lkml.kernel.org/r/20230809100754.3094517-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230809100754.3094517-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_alloc: remove unneeded variable baseMiaohe Lin1-3/+1
Since commit 5d0a661d808f ("mm/page_alloc: use only one PCP list for THP-sized allocations"), local variable base is just as same as order. So remove it. No functional change intended. Link: https://lkml.kernel.org/r/20230803114934.693989-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_alloc: avoid unneeded alike_pages calculationMiaohe Lin1-6/+5
When free_pages is 0, alike_pages is not used. So alike_pages calculation can be avoided by checking free_pages early to save cpu cycles. Also fix typo 'comparable'. It should be 'compatible' here. Link: https://lkml.kernel.org/r/20230801123723.2225543-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm: page_alloc: avoid false page outside zone error infoMiaohe Lin1-3/+2
If pfn is outside zone boundaries in the first round, ret will be set to 1. But if pfn is changed to inside the zone boundaries in zone span seqretry path, ret is still set to 1 leading to false page outside zone error info. This is from code inspection. The race window should be really small thus hard to trigger in real world. [akpm@linux-foundation.org: code simplification, per Matthew] Link: https://lkml.kernel.org/r/20230704111823.940331-1-linmiaohe@huawei.com Fixes: bdc8cb984576 ("[PATCH] memory hotplug locking: zone span seqlock") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm/page_alloc: use write_seqlock_irqsave() instead write_seqlock() + ↵Sebastian Andrzej Siewior1-9/+6
local_irq_save(). __build_all_zonelists() acquires zonelist_update_seq by first disabling interrupts via local_irq_save() and then acquiring the seqlock with write_seqlock(). This is troublesome and leads to problems on PREEMPT_RT. The problem is that the inner spinlock_t becomes a sleeping lock on PREEMPT_RT and must not be acquired with disabled interrupts. The API provides write_seqlock_irqsave() which does the right thing in one step. printk_deferred_enter() has to be invoked in non-migrate-able context to ensure that deferred printing is enabled and disabled on the same CPU. This is the case after zonelist_update_seq has been acquired. There was discussion on the first submission that the order should be: local_irq_disable(); printk_deferred_enter(); write_seqlock(); to avoid pitfalls like having an unaccounted printk() coming from write_seqlock_irqsave() before printk_deferred_enter() is invoked. The only origin of such a printk() can be a lockdep splat because the lockdep annotation happens after the sequence count is incremented. This is exceptional and subject to change. It was also pointed that PREEMPT_RT can be affected by the printk problem since its write_seqlock_irqsave() does not really disable interrupts. This isn't the case because PREEMPT_RT's printk implementation differs from the mainline implementation in two important aspects: - Printing happens in a dedicated threads and not at during the invocation of printk(). - In emergency cases where synchronous printing is used, a different driver is used which does not use tty_port::lock. Acquire zonelist_update_seq with write_seqlock_irqsave() and then defer printk output. Link: https://lkml.kernel.org/r/20230623201517.yw286Knb@linutronix.de Fixes: 1007843a91909 ("mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm/page_alloc: fix min_free_kbytes calculation regarding ZONE_MOVABLEliuq1-6/+6
The current calculation of min_free_kbytes only uses ZONE_DMA and ZONE_NORMAL pages,but the ZONE_MOVABLE zone->_watermark[WMARK_MIN] will also divide part of min_free_kbytes.This will cause the min watermark of ZONE_NORMAL to be too small in the presence of ZONE_MOVEABLE. __GFP_HIGH and PF_MEMALLOC allocations usually don't need movable zone pages, so just like ZONE_HIGHMEM, cap pages_min to a small value in __setup_per_zone_wmarks(). On my testing machine with 16GB of memory (transparent hugepage is turned off by default, and movablecore=12G is configured) The following is a comparative test data of watermark_min no patch add patch ZONE_DMA 1 8 ZONE_DMA32 151 709 ZONE_NORMAL 233 1113 ZONE_MOVABLE 1434 128 min_free_kbytes 7288 7326 Link: https://lkml.kernel.org/r/20230625031656.23941-1-liuq131@chinatelecom.cn Signed-off-by: liuq <liuq131@chinatelecom.cn> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-28Merge tag 'mm-stable-2023-06-24-19-15' of ↵Linus Torvalds1-749/+124
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ...
2023-06-24mm: page_alloc: use the correct type of list for free pagesBaolin Wang1-1/+1
Commit bf75f200569d ("mm/page_alloc: add page->buddy_list and page->pcp_list") introduces page->buddy_list and page->pcp_list as a union with page->lru, but missed to change get_page_from_free_area() to use page->buddy_list to clarify the correct type of list for a free page. Link: https://lkml.kernel.org/r/7e7ab533247d40c0ea0373c18a6a48e5667f9e10.1687333557.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-20mm: page_alloc: make compound_page_dtors staticMiaohe Lin1-1/+1
It's only used inside page_alloc.c now. So make it static and remove the declaration in mm.h. Link: https://lkml.kernel.org/r/20230617034622.1235913-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: remove unneeded header filesMiaohe Lin1-4/+0
Remove some unneeded header files. No functional change intended. Link: https://lkml.kernel.org/r/20230603112558.213694-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/page_alloc: don't wake kswapd from rmqueue() unless __GFP_KSWAPD_RECLAIM ↵Tetsuo Handa1-1/+2
is specified Commit 73444bc4d8f9 ("mm, page_alloc: do not wake kswapd with zone lock held") moved wakeup_kswapd() from steal_suitable_fallback() to rmqueue() using ZONE_BOOSTED_WATERMARK flag. Only allocation contexts that include ALLOC_KSWAPD (which corresponds to __GFP_KSWAPD_RECLAIM) should wake kswapd, for callers are supposed to remove __GFP_KSWAPD_RECLAIM if trying to hold pgdat->kswapd_wait has a risk of deadlock. But since zone->flags is a shared variable, a thread doing !__GFP_KSWAPD_RECLAIM allocation request might observe this flag being set immediately after another thread doing __GFP_KSWAPD_RECLAIM allocation request set this flag, causing possibility of deadlock. Link: https://lkml.kernel.org/r/c3c3dacf-dd3b-77c9-f96a-d0982b4b2a4f@I-love.SAKURA.ne.jp Fixes: 73444bc4d8f9 ("mm, page_alloc: do not wake kswapd with zone lock held") Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: compaction: simplify should_compact_retry()Johannes Weiner1-38/+19
The different branches for retry are unnecessarily complicated. There are really only three outcomes: progress (retry n times), skipped (retry if reclaim can help), failed (retry with higher priority). Rearrange the branches and the retry counter to make it simpler. [hannes@cmpxchg.org: restore behavior when hitting max_retries] Link: https://lkml.kernel.org/r/20230602144705.GB161817@cmpxchg.org Link: https://lkml.kernel.org/r/20230519123959.77335-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: compaction: remove compaction result helpersJohannes Weiner1-13/+17
Patch series "mm: compaction: cleanups & simplifications". These compaction cleanups are split out from the huge page allocator series[1], as requested by reviewer feedback. [1] https://lore.kernel.org/linux-mm/20230418191313.268131-1-hannes@cmpxchg.org/ This patch (of 5): The compaction result helpers encode quirks that are specific to the allocator's retry logic. E.g. COMPACT_SUCCESS and COMPACT_COMPLETE actually represent failures that should be retried upon, and so on. I frequently found myself pulling up the helper implementation in order to understand and work on the retry logic. They're not quite clean abstractions; rather they split the retry logic into two locations. Remove the helpers and inline the checks. Then comment on the result interpretations directly where the decision making happens. Link: https://lkml.kernel.org/r/20230519123959.77335-1-hannes@cmpxchg.org Link: https://lkml.kernel.org/r/20230519123959.77335-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: set sysctl_lowmem_reserve_ratio storage-class-specifier to ↵Tom Rix1-1/+1
static smatch reports mm/page_alloc.c:247:5: warning: symbol 'sysctl_lowmem_reserve_ratio' was not declared. Should it be static? This variable is only used in its defining file, so it should be static Link: https://lkml.kernel.org/r/20230518141119.927074-1-trix@redhat.com Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move is_check_pages_enabled() into page_alloc.cKefeng Wang1-1/+6
The is_check_pages_enabled() only used in page_alloc.c, move it into page_alloc.c, also use it in free_tail_page_prepare(). Link: https://lkml.kernel.org/r/20230516063821.121844-14-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move sysctls into it own filsKefeng Wang1-14/+89
This moves all page alloc related sysctls to its own file, as part of the kernel/sysctl.c spring cleaning, also move some functions declarations from mm.h into internal.h. Link: https://lkml.kernel.org/r/20230516063821.121844-13-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move pm_* function into powerKefeng Wang1-38/+0
pm_restrict_gfp_mask()/pm_restore_gfp_mask() only used in power, let's move them out of page_alloc.c. Adding a general gfp_has_io_fs() function which return true if gfp with both __GFP_IO and __GFP_FS flags, then use it inside of pm_suspended_storage(), also the pm_suspended_storage() is moved into suspend.h. Link: https://lkml.kernel.org/r/20230516063821.121844-11-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move mark_free_page() into snapshot.cKefeng Wang1-55/+0
The mark_free_page() is only used in kernel/power/snapshot.c, move it out to reduce a bit of page_alloc.c Link: https://lkml.kernel.org/r/20230516063821.121844-10-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: split out DEBUG_PAGEALLOCKefeng Wang1-69/+0
Move DEBUG_PAGEALLOC related functions into a single file to reduce a bit of page_alloc.c. Link: https://lkml.kernel.org/r/20230516063821.121844-9-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: split out FAIL_PAGE_ALLOCKefeng Wang1-74/+0
... to a single file to reduce a bit of page_alloc.c. Link: https://lkml.kernel.org/r/20230516063821.121844-8-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: remove alloc_contig_dump_pages() stubKefeng Wang1-7/+0
DEFINE_DYNAMIC_DEBUG_METADATA and DYNAMIC_DEBUG_BRANCH already has stub definitions without dynamic debug feature, remove unnecessary alloc_contig_dump_pages() stub. Link: https://lkml.kernel.org/r/20230516063821.121844-7-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: squash page_is_consistent()Kefeng Wang1-8/+1
Squash the page_is_consistent() into bad_range() as there is only one caller. Link: https://lkml.kernel.org/r/20230516063821.121844-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: collect mem statistic into show_mem.cKefeng Wang1-402/+0
Let's move show_mem.c from lib to mm, as it belongs memory subsystem, also split some memory statistic related functions from page_alloc.c to show_mem.c, and we cleanup some unneeded include. There is no functional change. Link: https://lkml.kernel.org/r/20230516063821.121844-5-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move set_zone_contiguous() into mm_init.cKefeng Wang1-27/+0
set_zone_contiguous() is only used in mm init/hotplug, and clear_zone_contiguous() only used in hotplug, move them from page_alloc.c to the more appropriate file. Link: https://lkml.kernel.org/r/20230516063821.121844-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move init_on_alloc/free() into mm_init.cKefeng Wang1-5/+0
Since commit f2fc4b44ec2b ("mm: move init_mem_debugging_and_hardening() to mm/mm_init.c"), the init_on_alloc() and init_on_free() define is better to move there too. Link: https://lkml.kernel.org/r/20230516063821.121844-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: page_alloc: move mirrored_kernelcore into mm_init.cKefeng Wang1-3/+0
Patch series "mm: page_alloc: misc cleanup and refactor", v2. This aims to reduce more space in page_alloc.c, also do some cleanup, no functional changes intended. This patch (of 13): Since commit 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c"), mirrored_kernelcore should be moved into mm_init.c, as most related codes are already there. Link: https://lkml.kernel.org/r/20230516063821.121844-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20230516063821.121844-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/page_alloc: drop the unnecessary pfn_valid() for start pfnBaolin Wang1-1/+1
__pageblock_pfn_to_page() currently performs both pfn_valid check and pfn_to_online_page(). The former one is redundant because the latter is a stronger check. Drop pfn_valid(). Link: https://lkml.kernel.org/r/c3868b58c6714c09a43440d7d02c7b4eed6e03f6.1682342634.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-06mm: Add support for unaccepted memoryKirill A. Shutemov1-0/+173
UEFI Specification version 2.9 introduces the concept of memory acceptance. Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP, require memory to be accepted before it can be used by the guest. Accepting happens via a protocol specific to the Virtual Machine platform. There are several ways the kernel can deal with unaccepted memory: 1. Accept all the memory during boot. It is easy to implement and it doesn't have runtime cost once the system is booted. The downside is very long boot time. Accept can be parallelized to multiple CPUs to keep it manageable (i.e. via DEFERRED_STRUCT_PAGE_INIT), but it tends to saturate memory bandwidth and does not scale beyond the point. 2. Accept a block of memory on the first use. It requires more infrastructure and changes in page allocator to make it work, but it provides good boot time. On-demand memory accept means latency spikes every time kernel steps onto a new memory block. The spikes will go away once workload data set size gets stabilized or all memory gets accepted. 3. Accept all memory in background. Introduce a thread (or multiple) that gets memory accepted proactively. It will minimize time the system experience latency spikes on memory allocation while keeping low boot time. This approach cannot function on its own. It is an extension of #2: background memory acceptance requires functional scheduler, but the page allocator may need to tap into unaccepted memory before that. The downside of the approach is that these threads also steal CPU cycles and memory bandwidth from the user's workload and may hurt user experience. Implement #1 and #2 for now. #2 is the default. Some workloads may want to use #1 with accept_memory=eager in kernel command line. #3 can be implemented later based on user's demands. Support of unaccepted memory requires a few changes in core-mm code: - memblock accepts memory on allocation. It serves early boot memory allocations and doesn't limit them to pre-accepted pool of memory. - page allocator accepts memory on the first allocation of the page. When kernel runs out of accepted memory, it accepts memory until the high watermark is reached. It helps to minimize fragmentation. EFI code will provide two helpers if the platform supports unaccepted memory: - accept_memory() makes a range of physical addresses accepted. - range_contains_unaccepted_memory() checks anything within the range of physical addresses requires acceptance. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mike Rapoport <rppt@linux.ibm.com> # memblock Link: https://lore.kernel.org/r/20230606142637.5171-2-kirill.shutemov@linux.intel.com
2023-05-04Merge tag 'mm-stable-2023-05-03-16-22' of ↵Linus Torvalds1-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - Some DAMON cleanups from Kefeng Wang - Some KSM work from David Hildenbrand, to make the PR_SET_MEMORY_MERGE ioctl's behavior more similar to KSM's behavior. [ Andrew called these "final", but I suspect we'll have a series fixing up the fact that the last commit in the dmapools series in the previous pull seems to have unintentionally just reverted all the other commits in the same series.. - Linus ] * tag 'mm-stable-2023-05-03-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm: hwpoison: coredump: support recovery from dump_user_range() mm/page_alloc: add some comments to explain the possible hole in __pageblock_pfn_to_page() mm/ksm: move disabling KSM from s390/gmap code to KSM code selftests/ksm: ksm_functional_tests: add prctl unmerge test mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0 mm/damon/paddr: fix missing folio_sz update in damon_pa_young() mm/damon/paddr: minor refactor of damon_pa_mark_accessed_or_deactivate() mm/damon/paddr: minor refactor of damon_pa_pageout()
2023-05-03mm/page_alloc: add some comments to explain the possible hole in ↵Baolin Wang1-0/+9
__pageblock_pfn_to_page() Now the __pageblock_pfn_to_page() is used by set_zone_contiguous(), which checks whether the given zone contains holes, and uses pfn_to_online_page() to validate if the start pfn is online and valid, as well as using pfn_valid() to validate the end pfn. However, the __pageblock_pfn_to_page() function may return non-NULL even if the end pfn of a pageblock is in a memory hole in some situations. For example, if the pageblock order is MAX_ORDER, which will fall into 2 sub-sections, and the end pfn of the pageblock may be hole even though the start pfn is online and valid. See below memory layout as an example and suppose the pageblock order is MAX_ORDER. [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff] [ 0.000000] DMA32 empty [ 0.000000] Normal [mem 0x0000000100000000-0x0000001fa7ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000040000000-0x0000001fa3c7ffff] [ 0.000000] node 0: [mem 0x0000001fa3c80000-0x0000001fa3ffffff] [ 0.000000] node 0: [mem 0x0000001fa4000000-0x0000001fa402ffff] [ 0.000000] node 0: [mem 0x0000001fa4030000-0x0000001fa40effff] [ 0.000000] node 0: [mem 0x0000001fa40f0000-0x0000001fa73cffff] [ 0.000000] node 0: [mem 0x0000001fa73d0000-0x0000001fa745ffff] [ 0.000000] node 0: [mem 0x0000001fa7460000-0x0000001fa746ffff] [ 0.000000] node 0: [mem 0x0000001fa7470000-0x0000001fa758ffff] [ 0.000000] node 0: [mem 0x0000001fa7590000-0x0000001fa7dfffff] Focus on the last memory range, and there is a hole for the range [mem 0x0000001fa7590000-0x0000001fa7dfffff]. That means the last pageblock will contain the range from 0x1fa7c00000 to 0x1fa7ffffff, since the pageblock must be 4M aligned. And in this pageblock, these pfns will fall into 2 sub-section (the sub-section size is 2M aligned). So, the 1st sub-section (indicates pfn range: 0x1fa7c00000 - 0x1fa7dfffff ) in this pageblock is valid by calling subsection_map_init() in free_area_init(), but the 2nd sub-section (indicates pfn range: 0x1fa7e00000 - 0x1fa7ffffff ) in this pageblock is not valid. This did not break anything until now, but the zone continuous is fragile in this possible scenario. So as previous discussion[1], it is better to add some comments to explain this possible issue in case there are some future pfn walkers that rely on this. [1] https://lore.kernel.org/all/87r0sdsmr6.fsf@yhuang6-desk2.ccr.corp.intel.com/ Link: https://lkml.kernel.org/r/5c26368865e79c743a453dea48d30670b19d2e4f.1682425534.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/5c26368865e79c743a453dea48d30670b19d2e4f.1682425534.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-29Merge tag 'cgroup-for-6.4' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - cpuset changes including the fix for an incorrect interaction with CPU hotplug and an optimization - Other doc and cosmetic changes * tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1/cpusets: update libcgroup project link cgroup/cpuset: Minor updates to test_cpuset_prs.sh cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset cpuset: Clean up cpuset_node_allowed cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers
2023-04-19mm, page_alloc: use check_pages_enabled static key to check tail pagesVlastimil Babka1-5/+5
Commit 700d2e9a36b9 ("mm, page_alloc: reduce page alloc/free sanity checks") has introduced a new static key check_pages_enabled to control when struct pages are sanity checked during allocation and freeing. Mel Gorman suggested that free_tail_pages_check() could use this static key as well, instead of relying on CONFIG_DEBUG_VM. That makes sense, so do that. Also rename the function to free_tail_page_prepare() because it works on a single tail page and has a struct page preparation component as well as the optional checking component. Also remove some unnecessary unlikely() within static_branch_unlikely() statements that Mel pointed out for commit 700d2e9a36b9. Link: https://lkml.kernel.org/r/20230405142840.11068-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Suggested-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Alexander Halbuer <halbuer@sra.uni-hannover.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changesAndrew Morton1-0/+19
2023-04-19mm: page_alloc: skip regions with hugetlbfs pages when allocating 1G pagesMel Gorman1-0/+3
A bug was reported by Yuanxi Liu where allocating 1G pages at runtime is taking an excessive amount of time for large amounts of memory. Further testing allocating huge pages that the cost is linear i.e. if allocating 1G pages in batches of 10 then the time to allocate nr_hugepages from 10->20->30->etc increases linearly even though 10 pages are allocated at each step. Profiles indicated that much of the time is spent checking the validity within already existing huge pages and then attempting a migration that fails after isolating the range, draining pages and a whole lot of other useless work. Commit eb14d4eefdc4 ("mm,page_alloc: drop unnecessary checks from pfn_range_valid_contig") removed two checks, one which ignored huge pages for contiguous allocations as huge pages can sometimes migrate. While there may be value on migrating a 2M page to satisfy a 1G allocation, it's potentially expensive if the 1G allocation fails and it's pointless to try moving a 1G page for a new 1G allocation or scan the tail pages for valid PFNs. Reintroduce the PageHuge check and assume any contiguous region with hugetlbfs pages is unsuitable for a new 1G allocation. The hpagealloc test allocates huge pages in batches and reports the average latency per page over time. This test happens just after boot when fragmentation is not an issue. Units are in milliseconds. hpagealloc 6.3.0-rc6 6.3.0-rc6 6.3.0-rc6 vanilla hugeallocrevert-v1r1 hugeallocsimple-v1r2 Min Latency 26.42 ( 0.00%) 5.07 ( 80.82%) 18.94 ( 28.30%) 1st-qrtle Latency 356.61 ( 0.00%) 5.34 ( 98.50%) 19.85 ( 94.43%) 2nd-qrtle Latency 697.26 ( 0.00%) 5.47 ( 99.22%) 20.44 ( 97.07%) 3rd-qrtle Latency 972.94 ( 0.00%) 5.50 ( 99.43%) 20.81 ( 97.86%) Max-1 Latency 26.42 ( 0.00%) 5.07 ( 80.82%) 18.94 ( 28.30%) Max-5 Latency 82.14 ( 0.00%) 5.11 ( 93.78%) 19.31 ( 76.49%) Max-10 Latency 150.54 ( 0.00%) 5.20 ( 96.55%) 19.43 ( 87.09%) Max-90 Latency 1164.45 ( 0.00%) 5.53 ( 99.52%) 20.97 ( 98.20%) Max-95 Latency 1223.06 ( 0.00%) 5.55 ( 99.55%) 21.06 ( 98.28%) Max-99 Latency 1278.67 ( 0.00%) 5.57 ( 99.56%) 22.56 ( 98.24%) Max Latency 1310.90 ( 0.00%) 8.06 ( 99.39%) 26.62 ( 97.97%) Amean Latency 678.36 ( 0.00%) 5.44 * 99.20%* 20.44 * 96.99%* 6.3.0-rc6 6.3.0-rc6 6.3.0-rc6 vanilla revert-v1 hugeallocfix-v2 Duration User 0.28 0.27 0.30 Duration System 808.66 17.77 35.99 Duration Elapsed 830.87 18.08 36.33 The vanilla kernel is poor, taking up to 1.3 second to allocate a huge page and almost 10 minutes in total to run the test. Reverting the problematic commit reduces it to 8ms at worst and the patch takes 26ms. This patch fixes the main issue with skipping huge pages but leaves the page_count() out because a page with an elevated count potentially can migrate. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=217022 Link: https://lkml.kernel.org/r/20230414141429.pwgieuwluxwez3rj@techsingularity.net Fixes: eb14d4eefdc4 ("mm,page_alloc: drop unnecessary checks from pfn_range_valid_contig") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Yuanxi Liu <y.liu@naruida.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlockTetsuo Handa1-0/+16
syzbot is reporting circular locking dependency which involves zonelist_update_seq seqlock [1], for this lock is checked by memory allocation requests which do not need to be retried. One deadlock scenario is kmalloc(GFP_ATOMIC) from an interrupt handler. CPU0 ---- __build_all_zonelists() { write_seqlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount odd // e.g. timer interrupt handler runs at this moment some_timer_func() { kmalloc(GFP_ATOMIC) { __alloc_pages_slowpath() { read_seqbegin(&zonelist_update_seq) { // spins forever because zonelist_update_seq.seqcount is odd } } } } // e.g. timer interrupt handler finishes write_sequnlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount even } This deadlock scenario can be easily eliminated by not calling read_seqbegin(&zonelist_update_seq) from !__GFP_DIRECT_RECLAIM allocation requests, for retry is applicable to only __GFP_DIRECT_RECLAIM allocation requests. But Michal Hocko does not know whether we should go with this approach. Another deadlock scenario which syzbot is reporting is a race between kmalloc(GFP_ATOMIC) from tty_insert_flip_string_and_push_buffer() with port->lock held and printk() from __build_all_zonelists() with zonelist_update_seq held. CPU0 CPU1 ---- ---- pty_write() { tty_insert_flip_string_and_push_buffer() { __build_all_zonelists() { write_seqlock(&zonelist_update_seq); build_zonelists() { printk() { vprintk() { vprintk_default() { vprintk_emit() { console_unlock() { console_flush_all() { console_emit_next_record() { con->write() = serial8250_console_write() { spin_lock_irqsave(&port->lock, flags); tty_insert_flip_string() { tty_insert_flip_string_fixed_flag() { __tty_buffer_request_room() { tty_buffer_alloc() { kmalloc(GFP_ATOMIC | __GFP_NOWARN) { __alloc_pages_slowpath() { zonelist_iter_begin() { read_seqbegin(&zonelist_update_seq); // spins forever because zonelist_update_seq.seqcount is odd spin_lock_irqsave(&port->lock, flags); // spins forever because port->lock is held } } } } } } } } spin_unlock_irqrestore(&port->lock, flags); // message is printed to console spin_unlock_irqrestore(&port->lock, flags); } } } } } } } } } write_sequnlock(&zonelist_update_seq); } } } This deadlock scenario can be eliminated by preventing interrupt context from calling kmalloc(GFP_ATOMIC) and preventing printk() from calling console_flush_all() while zonelist_update_seq.seqcount is odd. Since Petr Mladek thinks that __build_all_zonelists() can become a candidate for deferring printk() [2], let's address this problem by disabling local interrupts in order to avoid kmalloc(GFP_ATOMIC) and disabling synchronous printk() in order to avoid console_flush_all() . As a side effect of minimizing duration of zonelist_update_seq.seqcount being odd by disabling synchronous printk(), latency at read_seqbegin(&zonelist_update_seq) for both !__GFP_DIRECT_RECLAIM and __GFP_DIRECT_RECLAIM allocation requests will be reduced. Although, from lockdep perspective, not calling read_seqbegin(&zonelist_update_seq) (i.e. do not record unnecessary locking dependency) from interrupt context is still preferable, even if we don't allow calling kmalloc(GFP_ATOMIC) inside write_seqlock(&zonelist_update_seq)/write_sequnlock(&zonelist_update_seq) section... Link: https://lkml.kernel.org/r/8796b95c-3da3-5885-fddd-6ef55f30e4d3@I-love.SAKURA.ne.jp Fixes: 3d36424b3b58 ("mm/page_alloc: fix race condition between build_all_zonelists and page allocation") Link: https://lkml.kernel.org/r/ZCrs+1cDqPWTDFNM@alley [2] Reported-by: syzbot <syzbot+223c7461c58c58a4cb10@syzkaller.appspotmail.com> Link: https://syzkaller.appspot.com/bug?extid=223c7461c58c58a4cb10 [1] Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Petr Mladek <pmladek@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Patrick Daly <quic_pdaly@quicinc.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-06mm: move mem_init_print_info() to mm_init.cMike Rapoport (IBM)1-53/+0
mem_init_print_info() is only called from mm_core_init(). Move it close to the caller and make it static. Link: https://lkml.kernel.org/r/20230321170513.2401534-12-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Doug Berger <opendmb@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-06mm: move init_mem_debugging_and_hardening() to mm/mm_init.cMike Rapoport (IBM)1-95/+0
init_mem_debugging_and_hardening() is only called from mm_core_init(). Move it close to the caller, make it static and rename it to mem_debugging_and_hardening_init() for consistency with surrounding convention. Link: https://lkml.kernel.org/r/20230321170513.2401534-10-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Doug Berger <opendmb@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>