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2022-05-13vmscan: convert page buffer handling to use foliosMatthew Wilcox (Oracle)1-23/+25
This mostly just removes calls to compound_head() although nr_reclaimed should be incremented by the number of pages, not just 1. Link: https://lkml.kernel.org/r/20220504182857.4013401-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13vmscan: convert dirty page handling to foliosMatthew Wilcox (Oracle)1-22/+26
Mostly this just eliminates calls to compound_head(), but NR_VMSCAN_IMMEDIATE was being incremented by 1 instead of by nr_pages. Link: https://lkml.kernel.org/r/20220504182857.4013401-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13swap: convert add_to_swap() to take a folioMatthew Wilcox (Oracle)1-3/+3
The only caller already has a folio available, so this saves a conversion. Also convert the return type to boolean. Link: https://lkml.kernel.org/r/20220504182857.4013401-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13vmscan: convert the writeback handling in shrink_page_list() to foliosMatthew Wilcox (Oracle)1-36/+42
Slightly more efficient due to fewer calls to compound_head(). Link: https://lkml.kernel.org/r/20220504182857.4013401-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13vmscan: use folio_mapped() in shrink_page_list()Matthew Wilcox (Oracle)1-8/+8
Remove some legacy function calls. Link: https://lkml.kernel.org/r/20220504182857.4013401-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: don't use NUMA_NO_NODE as indicator of page on different nodeWei Yang1-4/+3
Now we are sure there is at least one page on page_list, so it is safe to get the nid of it. This means it is not necessary to use NUMA_NO_NODE as an indicator for the beginning of iteration or a page on different node. Link: https://lkml.kernel.org/r/20220429014426.29223-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: filter empty page_list at the beginningWei Yang1-4/+6
node_page_list would always be !empty on finishing the loop, except page_list is empty. Let's handle empty page_list before doing any real work including touching PF_MEMALLOC flag. Link: https://lkml.kernel.org/r/20220429014426.29223-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: use helper folio_is_file_lru()Miaohe Lin1-2/+2
Use helper folio_is_file_lru() to check whether folio is file lru. Minor readability improvement. [linmiaohe@huawei.com: use folio_is_file_lru()] Link: https://lkml.kernel.org/r/20220428105802.21389-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220425111232.23182-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: remove obsolete comment in kswapd_runMiaohe Lin1-1/+0
Since commit 6b700b5b3c59 ("mm/vmscan.c: remove cpu online notification for now"), cpu online notification is removed. So kswapd won't move to proper cpus if cpus are hot-added. Remove this obsolete comment. Link: https://lkml.kernel.org/r/20220425111232.23182-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: take all base pages of THP into account when race with ↵Miaohe Lin1-1/+1
speculative reference If the page has buffers, shrink_page_list will try to free the buffer mappings associated with the page and try to free the page as well. In the rare race with speculative reference, the page will be freed shortly by speculative reference. But nr_reclaimed is not incremented correctly when we come across the THP. We need to account all the base pages in this case. Link: https://lkml.kernel.org/r/20220425111232.23182-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: introduce helper function reclaim_page_list()Miaohe Lin1-25/+25
Introduce helper function reclaim_page_list() to eliminate the duplicated code of doing shrink_page_list() and putback_lru_page. Also we can separate node reclaim from node page list operation this way. No functional change intended. Link: https://lkml.kernel.org/r/20220425111232.23182-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: add a comment about MADV_FREE pages check in ↵Miaohe Lin1-1/+4
folio_check_dirty_writeback Patch series "A few cleanup and fixup patches for vmscan This series contains a few patches to remove obsolete comment, introduce helper to remove duplicated code and so no. Also we take all base pages of THP into account in rare race condition. More details can be found in the respective changelogs. This patch (of 6): The MADV_FREE pages check in folio_check_dirty_writeback is a bit hard to follow. Add a comment to make the code clear. Link: https://lkml.kernel.org/r/20220425111232.23182-2-linmiaohe@huawei.com Suggested-by: Huang, Ying <ying.huang@intel.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: not necessary to re-init the list for each iterationWei Yang1-3/+1
node_page_list is defined with LIST_HEAD and be cleaned until list_empty. So it is not necessary to re-init it again. [akpm@linux-foundation.org: remove unneeded braces] Link: https://lkml.kernel.org/r/20220426021743.21007-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/vmscan: take min_slab_pages into account when try to call shrink_nodeMiaohe Lin1-1/+2
Since commit 6b4f7799c6a5 ("mm: vmscan: invoke slab shrinkers from shrink_zone()"), slab reclaim and lru page reclaim are done together in the shrink_node. So we should take min_slab_pages into account when try to call shrink_node. Link: https://lkml.kernel.org/r/20220425112118.20924-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10fs: Remove aops->freepageMatthew Wilcox (Oracle)1-4/+0
All implementations now use free_folio so we can delete the callers and the method. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-10fs: Add free_folio address space operationMatthew Wilcox (Oracle)1-1/+5
Include documentation and convert the callers to use ->free_folio as well as ->freepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-10fs: Change try_to_free_buffers() to take a folioMatthew Wilcox (Oracle)1-1/+1
All but two of the callers already have a folio; pass a folio into try_to_free_buffers(). This removes the last user of cancel_dirty_page() so remove that wrapper function too. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-05-10mm: submit multipage write for SWP_FS_OPS swap-spaceNeilBrown1-2/+7
swap_writepage() is given one page at a time, but may be called repeatedly in succession. For block-device swapspace, the blk_plug functionality allows the multiple pages to be combined together at lower layers. That cannot be used for SWP_FS_OPS as blk_plug may not exist - it is only active when CONFIG_BLOCK=y. Consequently all swap reads over NFS are single page reads. With this patch we pass a pointer-to-pointer via the wbc. swap_writepage can store state between calls - much like the pointer passed explicitly to swap_readpage. After calling swap_writepage() some number of times, the state will be passed to swap_write_unplug() which can submit the combined request. Link: https://lkml.kernel.org/r/164859778128.29473.5191868522654408537.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10mm: reclaim mustn't enter FS for SWP_FS_OPS swap-spaceNeilBrown1-9/+20
If swap-out is using filesystem operations (SWP_FS_OPS), then it is not safe to enter the FS for reclaim. So only down-grade the requirement for swap pages to __GFP_IO after checking that SWP_FS_OPS are not being used. This makes the calculation of "may_enter_fs" slightly more complex, so move it into a separate function. with that done, there is little value in maintaining the bool variable any more. So replace the may_enter_fs variable with a may_enter_fs() function. This removes any risk for the variable becoming out-of-date. Link: https://lkml.kernel.org/r/164859778124.29473.16176717935781721855.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10mm: create new mm/swap.h header fileNeilBrown1-0/+1
Patch series "MM changes to improve swap-over-NFS support". Assorted improvements for swap-via-filesystem. This is a resend of these patches, rebased on current HEAD. The only substantial changes is that swap_dirty_folio has replaced swap_set_page_dirty. Currently swap-via-fs (SWP_FS_OPS) doesn't work for any filesystem. It has previously worked for NFS but that broke a few releases back. This series changes to use a new ->swap_rw rather than ->readpage and ->direct_IO. It also makes other improvements. There is a companion series already in linux-next which fixes various issues with NFS. Once both series land, a final patch is needed which changes NFS over to use ->swap_rw. This patch (of 10): Many functions declared in include/linux/swap.h are only used within mm/ Create a new "mm/swap.h" and move some of these declarations there. Remove the redundant 'extern' from the function declarations. [akpm@linux-foundation.org: mm/memory-failure.c needs mm/swap.h] Link: https://lkml.kernel.org/r/164859751830.29473.5309689752169286816.stgit@noble.brown Link: https://lkml.kernel.org/r/164859778120.29473.11725907882296224053.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-08fs: Convert is_dirty_writeback() to take a folioMatthew Wilcox (Oracle)1-1/+1
Pass a folio instead of a page to aops->is_dirty_writeback(). Convert both implementations and the caller. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-29mm/vmscan: fix comment for isolate_lru_pagesMiaohe Lin1-2/+2
Since commit 791b48b64232 ("mm: vmscan: scan until it finds eligible pages"), splicing any skipped pages to the tail of the LRU list won't put the system at risk of premature OOM but will waste lots of cpu cycles. Correct the comment accordingly. Link: https://lkml.kernel.org/r/20220416025231.8082-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29mm/vmscan: fix comment for current_may_throttleMiaohe Lin1-4/+3
Since commit 6d6435811c19 ("remove bdi_congested() and wb_congested() and related functions"), there is no congested backing device check anymore. Correct the comment accordingly. [akpm@linux-foundation.org: tweak grammar] Link: https://lkml.kernel.org/r/20220414120202.30082-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29mm/vmscan: remove obsolete comment in get_scan_countMiaohe Lin1-3/+1
Since commit 1431d4d11abb ("mm: base LRU balancing on an explicit cost model"), the relative value of each set of LRU lists is based on cost model instead of rotated/scanned ratio. Cleanup the relevant comment. Link: https://lkml.kernel.org/r/20220409030245.61211-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29mm/vmscan: sc->reclaim_idx must be a valid zone indexWei Yang1-2/+2
lruvec_lru_size() is only used in get_scan_count(), so the only possible zone_idx is sc->reclaim_idx. Since sc->reclaim_idx is ensured to be a valid zone idex, we can remove the extra check for zone iteration. Link: https://lkml.kernel.org/r/20220317234624.23358-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29mm/vmscan: reclaim only affects managed_zonesWei Yang1-2/+2
As mentioned in commit 6aa303defb74 ("mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator") , reclaim only affects managed_zones. Let's adjust the code and comment accordingly. Link: https://lkml.kernel.org/r/20220327024101.10378-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-03-23Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds1-149/+156
Pull folio updates from Matthew Wilcox: - Rewrite how munlock works to massively reduce the contention on i_mmap_rwsem (Hugh Dickins): https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/ - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig): https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/ - Convert GUP to use folios and make pincount available for order-1 pages. (Matthew Wilcox) - Convert a few more truncation functions to use folios (Matthew Wilcox) - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox) - Convert rmap_walk to use folios (Matthew Wilcox) - Convert most of shrink_page_list() to use a folio (Matthew Wilcox) - Add support for creating large folios in readahead (Matthew Wilcox) * tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits) mm/damon: minor cleanup for damon_pa_young selftests/vm/transhuge-stress: Support file-backed PMD folios mm/filemap: Support VM_HUGEPAGE for file mappings mm/readahead: Switch to page_cache_ra_order mm/readahead: Align file mappings for non-DAX mm/readahead: Add large folio readahead mm: Support arbitrary THP sizes mm: Make large folios depend on THP mm: Fix READ_ONLY_THP warning mm/filemap: Allow large folios to be added to the page cache mm: Turn can_split_huge_page() into can_split_folio() mm/vmscan: Convert pageout() to take a folio mm/vmscan: Turn page_check_references() into folio_check_references() mm/vmscan: Account large folios correctly mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios mm/vmscan: Free non-shmem folios without splitting them mm/rmap: Constify the rmap_walk_control argument mm/rmap: Convert rmap_walk() to take a folio mm: Turn page_anon_vma() into folio_anon_vma() mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read() ...
2022-03-23NUMA balancing: optimize page placement for memory tiering systemHuang Ying1-1/+5
With the advent of various new memory types, some machines will have multiple types of memory, e.g. DRAM and PMEM (persistent memory). The memory subsystem of these machines can be called memory tiering system, because the performance of the different types of memory are usually different. In such system, because of the memory accessing pattern changing etc, some pages in the slow memory may become hot globally. So in this patch, the NUMA balancing mechanism is enhanced to optimize the page placement among the different memory types according to hot/cold dynamically. In a typical memory tiering system, there are CPUs, fast memory and slow memory in each physical NUMA node. The CPUs and the fast memory will be put in one logical node (called fast memory node), while the slow memory will be put in another (faked) logical node (called slow memory node). That is, the fast memory is regarded as local while the slow memory is regarded as remote. So it's possible for the recently accessed pages in the slow memory node to be promoted to the fast memory node via the existing NUMA balancing mechanism. The original NUMA balancing mechanism will stop to migrate pages if the free memory of the target node becomes below the high watermark. This is a reasonable policy if there's only one memory type. But this makes the original NUMA balancing mechanism almost do not work to optimize page placement among different memory types. Details are as follows. It's the common cases that the working-set size of the workload is larger than the size of the fast memory nodes. Otherwise, it's unnecessary to use the slow memory at all. So, there are almost always no enough free pages in the fast memory nodes, so that the globally hot pages in the slow memory node cannot be promoted to the fast memory node. To solve the issue, we have 2 choices as follows, a. Ignore the free pages watermark checking when promoting hot pages from the slow memory node to the fast memory node. This will create some memory pressure in the fast memory node, thus trigger the memory reclaiming. So that, the cold pages in the fast memory node will be demoted to the slow memory node. b. Define a new watermark called wmark_promo which is higher than wmark_high, and have kswapd reclaiming pages until free pages reach such watermark. The scenario is as follows: when we want to promote hot-pages from a slow memory to a fast memory, but fast memory's free pages would go lower than high watermark with such promotion, we wake up kswapd with wmark_promo watermark in order to demote cold pages and free us up some space. So, next time we want to promote hot-pages we might have a chance of doing so. The choice "a" may create high memory pressure in the fast memory node. If the memory pressure of the workload is high, the memory pressure may become so high that the memory allocation latency of the workload is influenced, e.g. the direct reclaiming may be triggered. The choice "b" works much better at this aspect. If the memory pressure of the workload is high, the hot pages promotion will stop earlier because its allocation watermark is higher than that of the normal memory allocation. So in this patch, choice "b" is implemented. A new zone watermark (WMARK_PROMO) is added. Which is larger than the high watermark and can be controlled via watermark_scale_factor. In addition to the original page placement optimization among sockets, the NUMA balancing mechanism is extended to be used to optimize page placement according to hot/cold among different memory types. So the sysctl user space interface (numa_balancing) is extended in a backward compatible way as follow, so that the users can enable/disable these functionality individually. The sysctl is converted from a Boolean value to a bits field. The definition of the flags is, - 0: NUMA_BALANCING_DISABLED - 1: NUMA_BALANCING_NORMAL - 2: NUMA_BALANCING_MEMORY_TIERING We have tested the patch with the pmbench memory accessing benchmark with the 80:20 read/write ratio and the Gauss access address distribution on a 2 socket Intel server with Optane DC Persistent Memory Model. The test results shows that the pmbench score can improve up to 95.9%. Thanks Andrew Morton to help fix the document format error. Link: https://lkml.kernel.org/r/20220221084529.1052339-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Wei Xu <weixugc@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: zhongjiang-ali <zhongjiang-ali@linux.alibaba.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23mm: vmscan: fix documentation for page_check_references()Charan Teja Kalla1-1/+1
Commit b518154e59aa ("mm/vmscan: protect the workingset on anonymous LRU") requires to look twice for both mapped anon/file pages are used more than once to take the decission of reclaim or activation. Correct the documentation accordingly. Link: https://lkml.kernel.org/r/1646925640-21324-1-git-send-email-quic_charante@quicinc.com Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23mm: __isolate_lru_page_prepare() in isolate_migratepages_block()Hugh Dickins1-83/+18
__isolate_lru_page_prepare() conflates two unrelated functions, with the flags to one disjoint from the flags to the other; and hides some of the important checks outside of isolate_migratepages_block(), where the sequence is better to be visible. It comes from the days of lumpy reclaim, before compaction, when the combination made more sense. Move what's needed by mm/compaction.c isolate_migratepages_block() inline there, and what's needed by mm/vmscan.c isolate_lru_pages() inline there. Shorten "isolate_mode" to "mode", so the sequence of conditions is easier to read. Declare a "mapping" variable, to save one call to page_mapping() (but not another: calling again after page is locked is necessary). Simplify isolate_lru_pages() with a "move_to" list pointer. Link: https://lkml.kernel.org/r/879d62a8-91cc-d3c6-fb3b-69768236df68@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Alex Shi <alexs@kernel.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23mm/fs: delete PF_SWAPWRITEHugh Dickins1-6/+2
PF_SWAPWRITE has been redundant since v3.2 commit ee72886d8ed5 ("mm: vmscan: do not writeback filesystem pages in direct reclaim"). Coincidentally, NeilBrown's current patch "remove inode_congested()" deletes may_write_to_inode(), which appeared to be the one function which took notice of PF_SWAPWRITE. But if you study the old logic, and the conditions under which may_write_to_inode() was called, you discover that flag and function have been pointless for a decade. Link: https://lkml.kernel.org/r/75e80e7-742d-e3bd-531-614db8961e4@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: NeilBrown <neilb@suse.de> Cc: Jan Kara <jack@suse.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23remove bdi_congested() and wb_congested() and related functionsNeilBrown1-3/+1
These functions are no longer useful as no BDIs report congestions any more. Removing the test on bdi_write_contested() in current_may_throttle() could cause a small change in behaviour, but only when PF_LOCAL_THROTTLE is set. So replace the calls by 'false' and simplify the code - and remove the functions. [akpm@linux-foundation.org: fix build] Link: https://lkml.kernel.org/r/164549983742.9187.2570198746005819592.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nilfs] Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Paolo Valente <paolo.valente@linaro.org> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23remove inode_congested()NeilBrown1-16/+1
inode_congested() reports if the backing-device for the inode is congested. No bdi reports congestion any more, so this always returns 'false'. So remove inode_congested() and related functions, and remove the call sites, assuming that inode_congested() always returns 'false'. Link: https://lkml.kernel.org/r/164549983741.9187.2174285592262191311.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Paolo Valente <paolo.valente@linaro.org> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-21mm: Turn can_split_huge_page() into can_split_folio()Matthew Wilcox (Oracle)1-3/+3
This function already required a head page to be passed, so this just adds type-safety and removes a few implicit calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/vmscan: Convert pageout() to take a folioMatthew Wilcox (Oracle)1-32/+32
We always write out an entire folio at once. This conversion removes a few calls to compound_head() and gets the NR_VMSCAN_WRITE statistic right when writing out a large folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/vmscan: Turn page_check_references() into folio_check_references()Matthew Wilcox (Oracle)1-17/+16
This function only has one caller, and it already has a folio. This removes a number of calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/vmscan: Account large folios correctlyMatthew Wilcox (Oracle)1-6/+6
The statistics we gather should count the number of pages, not the number of folios. The logic in this function is somewhat convoluted, but even if we split the folio, I think the accounting is now correct. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/vmscan: Optimise shrink_page_list for non-PMD-sized foliosMatthew Wilcox (Oracle)1-1/+2
A large folio which is smaller than a PMD does not need to do the extra work in try_to_unmap() of trying to split a PMD entry. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/vmscan: Free non-shmem folios without splitting themMatthew Wilcox (Oracle)1-2/+2
We have to allocate memory in order to split a file-backed folio, so it's not a good idea to split them in the memory freeing path. It also doesn't work for XFS because pages have an extra reference count from page_has_private() and split_huge_page() expects that reference to have already been removed. Unfortunately, we still have to split shmem THPs because we can't handle swapping out an entire THP yet. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/rmap: Convert try_to_unmap() to take a folioMatthew Wilcox (Oracle)1-1/+1
Change all three callers and the worker function try_to_unmap_one(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-03-21mm/rmap: Turn page_referenced() into folio_referenced()Matthew Wilcox (Oracle)1-8/+12
Both its callers pass a page which was previously on an LRU list, so were passing a folio by definition. Use the type system to enforce that and remove a few calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm: Add split_folio_to_list()Matthew Wilcox (Oracle)1-5/+5
This is a convenience function; split_huge_page_to_list() can take any page in a folio (and does so on purpose because that page will be the one which keeps the refcount). But it's convenient for the callers to pass the folio instead of the first page in the folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm/vmscan: Turn page_check_dirty_writeback() into folio_check_dirty_writeback()Matthew Wilcox (Oracle)1-10/+10
Saves a few calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm: Convert remove_mapping() to take a folioMatthew Wilcox (Oracle)1-9/+14
Add kernel-doc and return the number of pages removed in order to get the statistics right in __invalidate_mapping_pages(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
2022-03-21mm/vmscan: Convert __remove_mapping() to take a folioMatthew Wilcox (Oracle)1-21/+23
This removes a few hidden calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm: Turn putback_lru_page() into folio_putback_lru()Matthew Wilcox (Oracle)1-8/+8
Add a putback_lru_page() wrapper. Removes a couple of compound_head() calls. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm/memcg: Convert mem_cgroup_swapout() to take a folioMatthew Wilcox (Oracle)1-1/+1
This removes an assumption that THPs are the only kind of compound pages and removes a couple of hidden calls to compound_head. It also documents that you can't pass a tail page to mem_cgroup_swapout(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm/workingset: Convert workingset_eviction() to take a folioMatthew Wilcox (Oracle)1-3/+4
This removes an assumption that THPs are the only kind of compound pages and removes a few hidden calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-03-21mm: Turn isolate_lru_page() into folio_isolate_lru()Matthew Wilcox (Oracle)1-24/+19
Add isolate_lru_page() as a wrapper around isolate_lru_folio(). TestClearPageLRU() would have always failed on a tail page, so returning -EBUSY is the same behaviour. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-02-17mm/thp: shrink_page_list() avoid splitting VM_LOCKED THPHugh Dickins1-3/+3
4.8 commit 7751b2da6be0 ("vmscan: split file huge pages before paging them out") inserted a split_huge_page_to_list() into shrink_page_list() without considering the mlock case: no problem if the page has already been marked as Mlocked (the !page_evictable check much higher up will have skipped all this), but it has always been the case that races or omissions in setting Mlocked can rely on page reclaim to detect this and correct it before actually reclaiming - and that remains so, but what a shame if a hugepage is needlessly split before discovering it. It is surprising that page_check_references() returns PAGEREF_RECLAIM when VM_LOCKED, but there was a good reason for that: try_to_unmap_one() is where the condition is detected and corrected; and until now it could not be done in page_referenced_one(), because that does not always have the page locked. Now that mlock's requirement for page lock has gone, copy try_to_unmap_one()'s mlock restoration into page_referenced_one(), and let page_check_references() return PAGEREF_ACTIVATE in this case. But page_referenced_one() may find a pte mapping one part of a hugepage: what hold should a pte mapped in a VM_LOCKED area exert over the entire huge page? That's debatable. The approach taken here is to treat that pte mapping in page_referenced_one() as if not VM_LOCKED, and if no VM_LOCKED pmd mapping is found later in the walk, and lack of reference permits, then PAGEREF_RECLAIM take it to attempted splitting as before. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>