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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Baolin Wang](/assets/img/avatar_default.png)
The mTHP swap related counters: 'anon_swpout' and 'anon_swpout_fallback' are confusing with an 'anon_' prefix, since the shmem can swap out non-anonymous pages. So drop the 'anon_' prefix to keep consistent with the old swap counter names. This is needed in 6.10-rcX to avoid having an inconsistent ABI out in the field. Link: https://lkml.kernel.org/r/7a8989c13299920d7589007a30065c3e2c19f0e0.1716431702.git.baolin.wang@linux.alibaba.com Fixes:d0f048ac39
("mm: add per-order mTHP anon_swpout and anon_swpout_fallback counters") Fixes:42248b9d34
("mm: add docs for per-order mTHP counters and transhuge_page ABI") Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Suggested-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
547 lines
14 KiB
C
547 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/mm/page_io.c
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*
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* Swap reorganised 29.12.95,
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* Asynchronous swapping added 30.12.95. Stephen Tweedie
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* Removed race in async swapping. 14.4.1996. Bruno Haible
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* Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie
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* Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman
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*/
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#include <linux/mm.h>
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#include <linux/kernel_stat.h>
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#include <linux/gfp.h>
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#include <linux/pagemap.h>
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#include <linux/swap.h>
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#include <linux/bio.h>
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#include <linux/swapops.h>
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#include <linux/writeback.h>
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#include <linux/blkdev.h>
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#include <linux/psi.h>
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#include <linux/uio.h>
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#include <linux/sched/task.h>
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#include <linux/delayacct.h>
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#include <linux/zswap.h>
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#include "swap.h"
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static void __end_swap_bio_write(struct bio *bio)
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{
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struct folio *folio = bio_first_folio_all(bio);
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if (bio->bi_status) {
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/*
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* We failed to write the page out to swap-space.
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* Re-dirty the page in order to avoid it being reclaimed.
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* Also print a dire warning that things will go BAD (tm)
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* very quickly.
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*
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* Also clear PG_reclaim to avoid folio_rotate_reclaimable()
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*/
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folio_mark_dirty(folio);
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pr_alert_ratelimited("Write-error on swap-device (%u:%u:%llu)\n",
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MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
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(unsigned long long)bio->bi_iter.bi_sector);
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folio_clear_reclaim(folio);
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}
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folio_end_writeback(folio);
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}
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static void end_swap_bio_write(struct bio *bio)
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{
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__end_swap_bio_write(bio);
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bio_put(bio);
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}
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static void __end_swap_bio_read(struct bio *bio)
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{
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struct folio *folio = bio_first_folio_all(bio);
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if (bio->bi_status) {
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pr_alert_ratelimited("Read-error on swap-device (%u:%u:%llu)\n",
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MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
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(unsigned long long)bio->bi_iter.bi_sector);
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} else {
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folio_mark_uptodate(folio);
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}
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folio_unlock(folio);
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}
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static void end_swap_bio_read(struct bio *bio)
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{
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__end_swap_bio_read(bio);
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bio_put(bio);
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}
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int generic_swapfile_activate(struct swap_info_struct *sis,
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struct file *swap_file,
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sector_t *span)
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{
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struct address_space *mapping = swap_file->f_mapping;
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struct inode *inode = mapping->host;
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unsigned blocks_per_page;
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unsigned long page_no;
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unsigned blkbits;
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sector_t probe_block;
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sector_t last_block;
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sector_t lowest_block = -1;
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sector_t highest_block = 0;
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int nr_extents = 0;
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int ret;
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blkbits = inode->i_blkbits;
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blocks_per_page = PAGE_SIZE >> blkbits;
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/*
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* Map all the blocks into the extent tree. This code doesn't try
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* to be very smart.
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*/
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probe_block = 0;
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page_no = 0;
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last_block = i_size_read(inode) >> blkbits;
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while ((probe_block + blocks_per_page) <= last_block &&
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page_no < sis->max) {
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unsigned block_in_page;
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sector_t first_block;
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cond_resched();
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first_block = probe_block;
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ret = bmap(inode, &first_block);
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if (ret || !first_block)
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goto bad_bmap;
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/*
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* It must be PAGE_SIZE aligned on-disk
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*/
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if (first_block & (blocks_per_page - 1)) {
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probe_block++;
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goto reprobe;
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}
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for (block_in_page = 1; block_in_page < blocks_per_page;
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block_in_page++) {
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sector_t block;
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block = probe_block + block_in_page;
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ret = bmap(inode, &block);
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if (ret || !block)
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goto bad_bmap;
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if (block != first_block + block_in_page) {
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/* Discontiguity */
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probe_block++;
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goto reprobe;
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}
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}
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first_block >>= (PAGE_SHIFT - blkbits);
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if (page_no) { /* exclude the header page */
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if (first_block < lowest_block)
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lowest_block = first_block;
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if (first_block > highest_block)
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highest_block = first_block;
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}
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/*
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* We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
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*/
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ret = add_swap_extent(sis, page_no, 1, first_block);
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if (ret < 0)
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goto out;
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nr_extents += ret;
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page_no++;
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probe_block += blocks_per_page;
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reprobe:
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continue;
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}
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ret = nr_extents;
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*span = 1 + highest_block - lowest_block;
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if (page_no == 0)
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page_no = 1; /* force Empty message */
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sis->max = page_no;
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sis->pages = page_no - 1;
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sis->highest_bit = page_no - 1;
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out:
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return ret;
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bad_bmap:
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pr_err("swapon: swapfile has holes\n");
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ret = -EINVAL;
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goto out;
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}
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/*
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* We may have stale swap cache pages in memory: notice
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* them here and get rid of the unnecessary final write.
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*/
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int swap_writepage(struct page *page, struct writeback_control *wbc)
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{
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struct folio *folio = page_folio(page);
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int ret;
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if (folio_free_swap(folio)) {
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folio_unlock(folio);
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return 0;
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}
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/*
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* Arch code may have to preserve more data than just the page
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* contents, e.g. memory tags.
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*/
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ret = arch_prepare_to_swap(folio);
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if (ret) {
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folio_mark_dirty(folio);
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folio_unlock(folio);
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return ret;
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}
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if (zswap_store(folio)) {
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folio_start_writeback(folio);
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folio_unlock(folio);
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folio_end_writeback(folio);
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return 0;
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}
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if (!mem_cgroup_zswap_writeback_enabled(folio_memcg(folio))) {
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folio_mark_dirty(folio);
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return AOP_WRITEPAGE_ACTIVATE;
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}
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__swap_writepage(folio, wbc);
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return 0;
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}
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static inline void count_swpout_vm_event(struct folio *folio)
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{
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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if (unlikely(folio_test_pmd_mappable(folio))) {
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count_memcg_folio_events(folio, THP_SWPOUT, 1);
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count_vm_event(THP_SWPOUT);
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}
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count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
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#endif
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count_vm_events(PSWPOUT, folio_nr_pages(folio));
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}
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#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
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static void bio_associate_blkg_from_page(struct bio *bio, struct folio *folio)
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{
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struct cgroup_subsys_state *css;
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struct mem_cgroup *memcg;
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memcg = folio_memcg(folio);
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if (!memcg)
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return;
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rcu_read_lock();
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css = cgroup_e_css(memcg->css.cgroup, &io_cgrp_subsys);
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bio_associate_blkg_from_css(bio, css);
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rcu_read_unlock();
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}
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#else
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#define bio_associate_blkg_from_page(bio, folio) do { } while (0)
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#endif /* CONFIG_MEMCG && CONFIG_BLK_CGROUP */
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struct swap_iocb {
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struct kiocb iocb;
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struct bio_vec bvec[SWAP_CLUSTER_MAX];
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int pages;
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int len;
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};
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static mempool_t *sio_pool;
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int sio_pool_init(void)
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{
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if (!sio_pool) {
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mempool_t *pool = mempool_create_kmalloc_pool(
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SWAP_CLUSTER_MAX, sizeof(struct swap_iocb));
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if (cmpxchg(&sio_pool, NULL, pool))
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mempool_destroy(pool);
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}
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if (!sio_pool)
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return -ENOMEM;
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return 0;
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}
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static void sio_write_complete(struct kiocb *iocb, long ret)
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{
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struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb);
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struct page *page = sio->bvec[0].bv_page;
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int p;
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if (ret != sio->len) {
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/*
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* In the case of swap-over-nfs, this can be a
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* temporary failure if the system has limited
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* memory for allocating transmit buffers.
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* Mark the page dirty and avoid
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* folio_rotate_reclaimable but rate-limit the
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* messages but do not flag PageError like
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* the normal direct-to-bio case as it could
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* be temporary.
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*/
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pr_err_ratelimited("Write error %ld on dio swapfile (%llu)\n",
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ret, page_file_offset(page));
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for (p = 0; p < sio->pages; p++) {
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page = sio->bvec[p].bv_page;
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set_page_dirty(page);
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ClearPageReclaim(page);
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}
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}
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for (p = 0; p < sio->pages; p++)
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end_page_writeback(sio->bvec[p].bv_page);
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mempool_free(sio, sio_pool);
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}
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static void swap_writepage_fs(struct folio *folio, struct writeback_control *wbc)
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{
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struct swap_iocb *sio = NULL;
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struct swap_info_struct *sis = swp_swap_info(folio->swap);
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struct file *swap_file = sis->swap_file;
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loff_t pos = folio_file_pos(folio);
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count_swpout_vm_event(folio);
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folio_start_writeback(folio);
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folio_unlock(folio);
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if (wbc->swap_plug)
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sio = *wbc->swap_plug;
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if (sio) {
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if (sio->iocb.ki_filp != swap_file ||
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sio->iocb.ki_pos + sio->len != pos) {
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swap_write_unplug(sio);
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sio = NULL;
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}
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}
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if (!sio) {
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sio = mempool_alloc(sio_pool, GFP_NOIO);
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init_sync_kiocb(&sio->iocb, swap_file);
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sio->iocb.ki_complete = sio_write_complete;
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sio->iocb.ki_pos = pos;
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sio->pages = 0;
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sio->len = 0;
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}
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bvec_set_folio(&sio->bvec[sio->pages], folio, folio_size(folio), 0);
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sio->len += folio_size(folio);
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sio->pages += 1;
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if (sio->pages == ARRAY_SIZE(sio->bvec) || !wbc->swap_plug) {
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swap_write_unplug(sio);
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sio = NULL;
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}
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if (wbc->swap_plug)
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*wbc->swap_plug = sio;
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}
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static void swap_writepage_bdev_sync(struct folio *folio,
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struct writeback_control *wbc, struct swap_info_struct *sis)
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{
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struct bio_vec bv;
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struct bio bio;
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bio_init(&bio, sis->bdev, &bv, 1,
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REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc));
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bio.bi_iter.bi_sector = swap_folio_sector(folio);
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bio_add_folio_nofail(&bio, folio, folio_size(folio), 0);
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bio_associate_blkg_from_page(&bio, folio);
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count_swpout_vm_event(folio);
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folio_start_writeback(folio);
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folio_unlock(folio);
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submit_bio_wait(&bio);
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__end_swap_bio_write(&bio);
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}
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static void swap_writepage_bdev_async(struct folio *folio,
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struct writeback_control *wbc, struct swap_info_struct *sis)
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{
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struct bio *bio;
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bio = bio_alloc(sis->bdev, 1,
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REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc),
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GFP_NOIO);
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bio->bi_iter.bi_sector = swap_folio_sector(folio);
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bio->bi_end_io = end_swap_bio_write;
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bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
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bio_associate_blkg_from_page(bio, folio);
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count_swpout_vm_event(folio);
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folio_start_writeback(folio);
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folio_unlock(folio);
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submit_bio(bio);
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}
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void __swap_writepage(struct folio *folio, struct writeback_control *wbc)
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{
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struct swap_info_struct *sis = swp_swap_info(folio->swap);
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VM_BUG_ON_FOLIO(!folio_test_swapcache(folio), folio);
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/*
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* ->flags can be updated non-atomicially (scan_swap_map_slots),
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* but that will never affect SWP_FS_OPS, so the data_race
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* is safe.
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*/
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if (data_race(sis->flags & SWP_FS_OPS))
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swap_writepage_fs(folio, wbc);
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else if (sis->flags & SWP_SYNCHRONOUS_IO)
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swap_writepage_bdev_sync(folio, wbc, sis);
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else
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swap_writepage_bdev_async(folio, wbc, sis);
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}
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void swap_write_unplug(struct swap_iocb *sio)
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{
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struct iov_iter from;
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struct address_space *mapping = sio->iocb.ki_filp->f_mapping;
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int ret;
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iov_iter_bvec(&from, ITER_SOURCE, sio->bvec, sio->pages, sio->len);
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ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
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if (ret != -EIOCBQUEUED)
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sio_write_complete(&sio->iocb, ret);
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}
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static void sio_read_complete(struct kiocb *iocb, long ret)
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{
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struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb);
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int p;
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if (ret == sio->len) {
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for (p = 0; p < sio->pages; p++) {
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struct folio *folio = page_folio(sio->bvec[p].bv_page);
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folio_mark_uptodate(folio);
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folio_unlock(folio);
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}
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count_vm_events(PSWPIN, sio->pages);
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} else {
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for (p = 0; p < sio->pages; p++) {
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struct folio *folio = page_folio(sio->bvec[p].bv_page);
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folio_unlock(folio);
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}
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pr_alert_ratelimited("Read-error on swap-device\n");
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}
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mempool_free(sio, sio_pool);
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}
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static void swap_read_folio_fs(struct folio *folio, struct swap_iocb **plug)
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{
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struct swap_info_struct *sis = swp_swap_info(folio->swap);
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struct swap_iocb *sio = NULL;
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loff_t pos = folio_file_pos(folio);
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if (plug)
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sio = *plug;
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if (sio) {
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if (sio->iocb.ki_filp != sis->swap_file ||
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sio->iocb.ki_pos + sio->len != pos) {
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swap_read_unplug(sio);
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sio = NULL;
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}
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}
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if (!sio) {
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sio = mempool_alloc(sio_pool, GFP_KERNEL);
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init_sync_kiocb(&sio->iocb, sis->swap_file);
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sio->iocb.ki_pos = pos;
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sio->iocb.ki_complete = sio_read_complete;
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sio->pages = 0;
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sio->len = 0;
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}
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bvec_set_folio(&sio->bvec[sio->pages], folio, folio_size(folio), 0);
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sio->len += folio_size(folio);
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sio->pages += 1;
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if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) {
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swap_read_unplug(sio);
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sio = NULL;
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}
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if (plug)
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*plug = sio;
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}
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static void swap_read_folio_bdev_sync(struct folio *folio,
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struct swap_info_struct *sis)
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{
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struct bio_vec bv;
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struct bio bio;
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bio_init(&bio, sis->bdev, &bv, 1, REQ_OP_READ);
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bio.bi_iter.bi_sector = swap_folio_sector(folio);
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|
bio_add_folio_nofail(&bio, folio, folio_size(folio), 0);
|
|
/*
|
|
* Keep this task valid during swap readpage because the oom killer may
|
|
* attempt to access it in the page fault retry time check.
|
|
*/
|
|
get_task_struct(current);
|
|
count_vm_event(PSWPIN);
|
|
submit_bio_wait(&bio);
|
|
__end_swap_bio_read(&bio);
|
|
put_task_struct(current);
|
|
}
|
|
|
|
static void swap_read_folio_bdev_async(struct folio *folio,
|
|
struct swap_info_struct *sis)
|
|
{
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
|
|
bio->bi_iter.bi_sector = swap_folio_sector(folio);
|
|
bio->bi_end_io = end_swap_bio_read;
|
|
bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
|
|
count_vm_event(PSWPIN);
|
|
submit_bio(bio);
|
|
}
|
|
|
|
void swap_read_folio(struct folio *folio, bool synchronous,
|
|
struct swap_iocb **plug)
|
|
{
|
|
struct swap_info_struct *sis = swp_swap_info(folio->swap);
|
|
bool workingset = folio_test_workingset(folio);
|
|
unsigned long pflags;
|
|
bool in_thrashing;
|
|
|
|
VM_BUG_ON_FOLIO(!folio_test_swapcache(folio) && !synchronous, folio);
|
|
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
|
|
VM_BUG_ON_FOLIO(folio_test_uptodate(folio), folio);
|
|
|
|
/*
|
|
* Count submission time as memory stall and delay. When the device
|
|
* is congested, or the submitting cgroup IO-throttled, submission
|
|
* can be a significant part of overall IO time.
|
|
*/
|
|
if (workingset) {
|
|
delayacct_thrashing_start(&in_thrashing);
|
|
psi_memstall_enter(&pflags);
|
|
}
|
|
delayacct_swapin_start();
|
|
|
|
if (zswap_load(folio)) {
|
|
folio_mark_uptodate(folio);
|
|
folio_unlock(folio);
|
|
} else if (data_race(sis->flags & SWP_FS_OPS)) {
|
|
swap_read_folio_fs(folio, plug);
|
|
} else if (synchronous || (sis->flags & SWP_SYNCHRONOUS_IO)) {
|
|
swap_read_folio_bdev_sync(folio, sis);
|
|
} else {
|
|
swap_read_folio_bdev_async(folio, sis);
|
|
}
|
|
|
|
if (workingset) {
|
|
delayacct_thrashing_end(&in_thrashing);
|
|
psi_memstall_leave(&pflags);
|
|
}
|
|
delayacct_swapin_end();
|
|
}
|
|
|
|
void __swap_read_unplug(struct swap_iocb *sio)
|
|
{
|
|
struct iov_iter from;
|
|
struct address_space *mapping = sio->iocb.ki_filp->f_mapping;
|
|
int ret;
|
|
|
|
iov_iter_bvec(&from, ITER_DEST, sio->bvec, sio->pages, sio->len);
|
|
ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
|
|
if (ret != -EIOCBQUEUED)
|
|
sio_read_complete(&sio->iocb, ret);
|
|
}
|