The patch titled
Subject: mm: swap: remove 'synchronous' argument to swap_read_folio()
has been added to the -mm mm-unstable branch. Its filename is
mm-swap-remove-synchronous-argument-to-swap_read_folio.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-remove-synchronous-argument-to-swap_read_folio.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: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Subject: mm: swap: remove 'synchronous' argument to swap_read_folio()
Date: Fri, 7 Jun 2024 04:55:15 +0000
Commit [1] introduced IO polling support duding swapin to reduce swap read
latency for block devices that can be polled. However later commit [2]
removed polling support. Commit [3] removed the remnants of polling
support from read_swap_cache_async() and __read_swap_cache_async().
However, it left behind some remnants in swap_read_folio(), the
'synchronous' argument.
swap_read_folio() reads the folio synchronously if synchronous=true or if
SWP_SYNCHRONOUS_IO is set in swap_info_struct. The only caller that
passes synchronous=true is in do_swap_page() in the SWP_SYNCHRONOUS_IO
case.
Hence, the argument is redundant, it is only set to true when the swap
read would have been synchronous anyway. Remove it.
[1] Commit 23955622ff8d ("swap: add block io poll in swapin path")
[2] Commit 9650b453a3d4 ("block: ignore RWF_HIPRI hint for sync dio")
[3] Commit b243dcbf2f13 ("swap: remove remnants of polling from read_swap_cache_async")
Link: https://lkml.kernel.org/r/20240607045515.1836558-1-yosryahmed@xxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 2 +-
mm/page_io.c | 6 +++---
mm/swap.h | 6 ++----
mm/swap_state.c | 10 +++++-----
4 files changed, 11 insertions(+), 13 deletions(-)
--- a/mm/memory.c~mm-swap-remove-synchronous-argument-to-swap_read_folio
+++ a/mm/memory.c
@@ -4113,7 +4113,7 @@ vm_fault_t do_swap_page(struct vm_fault
/* To provide entry to swap_read_folio() */
folio->swap = entry;
- swap_read_folio(folio, true, NULL);
+ swap_read_folio(folio, NULL);
folio->private = NULL;
}
} else {
--- a/mm/page_io.c~mm-swap-remove-synchronous-argument-to-swap_read_folio
+++ a/mm/page_io.c
@@ -493,10 +493,10 @@ static void swap_read_folio_bdev_async(s
submit_bio(bio);
}
-void swap_read_folio(struct folio *folio, bool synchronous,
- struct swap_iocb **plug)
+void swap_read_folio(struct folio *folio, struct swap_iocb **plug)
{
struct swap_info_struct *sis = swp_swap_info(folio->swap);
+ bool synchronous = sis->flags & SWP_SYNCHRONOUS_IO;
bool workingset = folio_test_workingset(folio);
unsigned long pflags;
bool in_thrashing;
@@ -521,7 +521,7 @@ void swap_read_folio(struct folio *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)) {
+ } else if (synchronous) {
swap_read_folio_bdev_sync(folio, sis);
} else {
swap_read_folio_bdev_async(folio, sis);
--- a/mm/swap.h~mm-swap-remove-synchronous-argument-to-swap_read_folio
+++ a/mm/swap.h
@@ -11,8 +11,7 @@ struct mempolicy;
/* linux/mm/page_io.c */
int sio_pool_init(void);
struct swap_iocb;
-void swap_read_folio(struct folio *folio, bool do_poll,
- struct swap_iocb **plug);
+void swap_read_folio(struct folio *folio, struct swap_iocb **plug);
void __swap_read_unplug(struct swap_iocb *plug);
static inline void swap_read_unplug(struct swap_iocb *plug)
{
@@ -83,8 +82,7 @@ static inline unsigned int folio_swap_fl
}
#else /* CONFIG_SWAP */
struct swap_iocb;
-static inline void swap_read_folio(struct folio *folio, bool do_poll,
- struct swap_iocb **plug)
+static inline void swap_read_folio(struct folio *folio, struct swap_iocb **plug)
{
}
static inline void swap_write_unplug(struct swap_iocb *sio)
--- a/mm/swap_state.c~mm-swap-remove-synchronous-argument-to-swap_read_folio
+++ a/mm/swap_state.c
@@ -567,7 +567,7 @@ struct folio *read_swap_cache_async(swp_
mpol_cond_put(mpol);
if (page_allocated)
- swap_read_folio(folio, false, plug);
+ swap_read_folio(folio, plug);
return folio;
}
@@ -684,7 +684,7 @@ struct folio *swap_cluster_readahead(swp
if (!folio)
continue;
if (page_allocated) {
- swap_read_folio(folio, false, &splug);
+ swap_read_folio(folio, &splug);
if (offset != entry_offset) {
folio_set_readahead(folio);
count_vm_event(SWAP_RA);
@@ -701,7 +701,7 @@ skip:
&page_allocated, false);
if (unlikely(page_allocated)) {
zswap_folio_swapin(folio);
- swap_read_folio(folio, false, NULL);
+ swap_read_folio(folio, NULL);
}
return folio;
}
@@ -834,7 +834,7 @@ static struct folio *swap_vma_readahead(
if (!folio)
continue;
if (page_allocated) {
- swap_read_folio(folio, false, &splug);
+ swap_read_folio(folio, &splug);
if (addr != vmf->address) {
folio_set_readahead(folio);
count_vm_event(SWAP_RA);
@@ -853,7 +853,7 @@ skip:
&page_allocated, false);
if (unlikely(page_allocated)) {
zswap_folio_swapin(folio);
- swap_read_folio(folio, false, NULL);
+ swap_read_folio(folio, NULL);
}
return folio;
}
_
Patches currently in -mm which might be from yosryahmed@xxxxxxxxxx are
mm-zswap-use-sg_set_folio-in-zswap_compress-decompress.patch
mm-zswap-use-kmap_local_folio-in-zswap_load.patch
mm-zswap-make-same_filled-functions-folio-friendly.patch
mm-rmap-abstract-updating-per-node-and-per-memcg-stats.patch
mm-zsmalloc-share-slab-caches-for-all-zsmalloc-zpools.patch
mm-swap-remove-synchronous-argument-to-swap_read_folio.patch
