The patch titled
Subject: mm: swap: extend swap_shmem_alloc() to support batch SWAP_MAP_SHMEM flag setting
has been added to the -mm mm-unstable branch. Its filename is
mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: swap: extend swap_shmem_alloc() to support batch SWAP_MAP_SHMEM flag setting
Date: Tue, 18 Jun 2024 14:54:14 +0800
To support shmem large folio swap operations, add a new parameter to
swap_shmem_alloc() that allows batch SWAP_MAP_SHMEM flag setting for shmem
swap entries.
While we are at it, use folio_nr_pages() to get the number of pages of the
folio as preparation.
Link: https://lkml.kernel.org/r/4909c4bf2f28665c6a35cd7e77990c5defc3d7fb.1718690645.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Barry Song <21cnbao@xxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: Daniel Gomez <da.gomez@xxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Lance Yang <ioworker0@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 4 -
mm/shmem.c | 6 +-
mm/swapfile.c | 98 +++++++++++++++++++++--------------------
3 files changed, 57 insertions(+), 51 deletions(-)
--- a/include/linux/swap.h~mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting
+++ a/include/linux/swap.h
@@ -475,7 +475,7 @@ void put_swap_folio(struct folio *folio,
extern swp_entry_t get_swap_page_of_type(int);
extern int get_swap_pages(int n, swp_entry_t swp_entries[], int order);
extern int add_swap_count_continuation(swp_entry_t, gfp_t);
-extern void swap_shmem_alloc(swp_entry_t);
+extern void swap_shmem_alloc(swp_entry_t, int);
extern int swap_duplicate(swp_entry_t);
extern int swapcache_prepare(swp_entry_t);
extern void swap_free_nr(swp_entry_t entry, int nr_pages);
@@ -542,7 +542,7 @@ static inline int add_swap_count_continu
return 0;
}
-static inline void swap_shmem_alloc(swp_entry_t swp)
+static inline void swap_shmem_alloc(swp_entry_t swp, int nr)
{
}
--- a/mm/shmem.c~mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting
+++ a/mm/shmem.c
@@ -1432,6 +1432,7 @@ static int shmem_writepage(struct page *
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
swp_entry_t swap;
pgoff_t index;
+ int nr_pages;
/*
* Our capabilities prevent regular writeback or sync from ever calling
@@ -1464,6 +1465,7 @@ static int shmem_writepage(struct page *
}
index = folio->index;
+ nr_pages = folio_nr_pages(folio);
/*
* This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC
@@ -1516,8 +1518,8 @@ static int shmem_writepage(struct page *
if (add_to_swap_cache(folio, swap,
__GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN,
NULL) == 0) {
- shmem_recalc_inode(inode, 0, 1);
- swap_shmem_alloc(swap);
+ shmem_recalc_inode(inode, 0, nr_pages);
+ swap_shmem_alloc(swap, nr_pages);
shmem_delete_from_page_cache(folio, swp_to_radix_entry(swap));
mutex_unlock(&shmem_swaplist_mutex);
--- a/mm/swapfile.c~mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting
+++ a/mm/swapfile.c
@@ -3377,62 +3377,58 @@ void si_swapinfo(struct sysinfo *val)
* - swap-cache reference is requested but the entry is not used. -> ENOENT
* - swap-mapped reference requested but needs continued swap count. -> ENOMEM
*/
-static int __swap_duplicate(swp_entry_t entry, unsigned char usage)
+static int __swap_duplicate(struct swap_info_struct *p, unsigned long offset,
+ int nr, unsigned char usage)
{
- struct swap_info_struct *p;
struct swap_cluster_info *ci;
- unsigned long offset;
unsigned char count;
unsigned char has_cache;
- int err;
+ int err, i;
- p = swp_swap_info(entry);
-
- offset = swp_offset(entry);
ci = lock_cluster_or_swap_info(p, offset);
- count = p->swap_map[offset];
-
- /*
- * swapin_readahead() doesn't check if a swap entry is valid, so the
- * swap entry could be SWAP_MAP_BAD. Check here with lock held.
- */
- if (unlikely(swap_count(count) == SWAP_MAP_BAD)) {
- err = -ENOENT;
- goto unlock_out;
- }
+ for (i = 0; i < nr; i++) {
+ count = p->swap_map[offset + i];
- has_cache = count & SWAP_HAS_CACHE;
- count &= ~SWAP_HAS_CACHE;
- err = 0;
-
- if (usage == SWAP_HAS_CACHE) {
-
- /* set SWAP_HAS_CACHE if there is no cache and entry is used */
- if (!has_cache && count)
- has_cache = SWAP_HAS_CACHE;
- else if (has_cache) /* someone else added cache */
- err = -EEXIST;
- else /* no users remaining */
+ /*
+ * swapin_readahead() doesn't check if a swap entry is valid, so the
+ * swap entry could be SWAP_MAP_BAD. Check here with lock held.
+ */
+ if (unlikely(swap_count(count) == SWAP_MAP_BAD)) {
err = -ENOENT;
+ break;
+ }
- } else if (count || has_cache) {
+ has_cache = count & SWAP_HAS_CACHE;
+ count &= ~SWAP_HAS_CACHE;
+ err = 0;
+
+ if (usage == SWAP_HAS_CACHE) {
+ /* set SWAP_HAS_CACHE if there is no cache and entry is used */
+ if (!has_cache && count)
+ has_cache = SWAP_HAS_CACHE;
+ else if (has_cache) /* someone else added cache */
+ err = -EEXIST;
+ else /* no users remaining */
+ err = -ENOENT;
+ } else if (count || has_cache) {
+ if ((count & ~COUNT_CONTINUED) < SWAP_MAP_MAX)
+ count += usage;
+ else if ((count & ~COUNT_CONTINUED) > SWAP_MAP_MAX)
+ err = -EINVAL;
+ else if (swap_count_continued(p, offset + i, count))
+ count = COUNT_CONTINUED;
+ else
+ err = -ENOMEM;
+ } else
+ err = -ENOENT; /* unused swap entry */
- if ((count & ~COUNT_CONTINUED) < SWAP_MAP_MAX)
- count += usage;
- else if ((count & ~COUNT_CONTINUED) > SWAP_MAP_MAX)
- err = -EINVAL;
- else if (swap_count_continued(p, offset, count))
- count = COUNT_CONTINUED;
- else
- err = -ENOMEM;
- } else
- err = -ENOENT; /* unused swap entry */
+ if (err)
+ break;
- if (!err)
- WRITE_ONCE(p->swap_map[offset], count | has_cache);
+ WRITE_ONCE(p->swap_map[offset + i], count | has_cache);
+ }
-unlock_out:
unlock_cluster_or_swap_info(p, ci);
return err;
}
@@ -3441,9 +3437,12 @@ unlock_out:
* Help swapoff by noting that swap entry belongs to shmem/tmpfs
* (in which case its reference count is never incremented).
*/
-void swap_shmem_alloc(swp_entry_t entry)
+void swap_shmem_alloc(swp_entry_t entry, int nr)
{
- __swap_duplicate(entry, SWAP_MAP_SHMEM);
+ struct swap_info_struct *p = swp_swap_info(entry);
+ unsigned long offset = swp_offset(entry);
+
+ __swap_duplicate(p, offset, nr, SWAP_MAP_SHMEM);
}
/*
@@ -3455,9 +3454,11 @@ void swap_shmem_alloc(swp_entry_t entry)
*/
int swap_duplicate(swp_entry_t entry)
{
+ struct swap_info_struct *p = swp_swap_info(entry);
+ unsigned long offset = swp_offset(entry);
int err = 0;
- while (!err && __swap_duplicate(entry, 1) == -ENOMEM)
+ while (!err && __swap_duplicate(p, offset, 1, 1) == -ENOMEM)
err = add_swap_count_continuation(entry, GFP_ATOMIC);
return err;
}
@@ -3472,7 +3473,10 @@ int swap_duplicate(swp_entry_t entry)
*/
int swapcache_prepare(swp_entry_t entry)
{
- return __swap_duplicate(entry, SWAP_HAS_CACHE);
+ struct swap_info_struct *p = swp_swap_info(entry);
+ unsigned long offset = swp_offset(entry);
+
+ return __swap_duplicate(p, offset, 1, SWAP_HAS_CACHE);
}
void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
mm-memory-extend-finish_fault-to-support-large-folio.patch
mm-memory-extend-finish_fault-to-support-large-folio-fix.patch
mm-memory-extend-finish_fault-to-support-large-folio-fix-fix.patch
mm-shmem-add-thp-validation-for-pmd-mapped-thp-related-statistics.patch
mm-shmem-add-multi-size-thp-sysfs-interface-for-anonymous-shmem.patch
mm-shmem-add-multi-size-thp-sysfs-interface-for-anonymous-shmem-fix.patch
mm-shmem-add-multi-size-thp-sysfs-interface-for-anonymous-shmem-fix-3.patch
mm-shmem-add-mthp-support-for-anonymous-shmem.patch
mm-shmem-add-mthp-size-alignment-in-shmem_get_unmapped_area.patch
mm-shmem-add-mthp-counters-for-anonymous-shmem.patch
mm-shmem-add-mthp-counters-for-anonymous-shmem-fix.patch
mm-memcontrol-add-vm_bug_on_folio-to-catch-lru-folio-in-mem_cgroup_migrate.patch
mm-vmscan-add-validation-before-spliting-shmem-large-folio.patch
mm-swap-extend-swap_shmem_alloc-to-support-batch-swap_map_shmem-flag-setting.patch
mm-shmem-extend-shmem_partial_swap_usage-to-support-large-folio-swap.patch
mm-filemap-use-xa_get_order-to-get-the-swap-entry-order.patch
mm-shmem-use-swap_free_nr-to-free-shmem-swap-entries.patch
mm-shmem-support-large-folio-allocation-for-shmem_replace_folio.patch
mm-shmem-drop-folio-reference-count-using-nr_pages-in-shmem_delete_from_page_cache.patch
mm-shmem-support-large-folio-swap-out.patch
