mm: swap: remove 'synchronous' argument to swap_read_folio()

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 23955622ff ("swap: add block io poll in swapin path")
[2] Commit 9650b453a3 ("block: ignore RWF_HIPRI hint for sync dio")
[3] Commit b243dcbf2f ("swap: remove remnants of polling from read_swap_cache_async")

Link: https://lkml.kernel.org/r/20240607045515.1836558-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yosry Ahmed 2024-06-07 04:55:15 +00:00 committed by Andrew Morton
parent 90b8fab5cd
commit b2d1f38b52
4 changed files with 11 additions and 13 deletions

View File

@ -4115,7 +4115,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
/* 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 {

View File

@ -493,10 +493,10 @@ static void swap_read_folio_bdev_async(struct folio *folio,
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, bool synchronous,
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);

View File

@ -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_flags(struct folio *folio)
}
#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)

View File

@ -567,7 +567,7 @@ struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
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_entry_t entry, gfp_t gfp_mask,
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 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
&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(swp_entry_t targ_entry, gfp_t gfp_mask,
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 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
&page_allocated, false);
if (unlikely(page_allocated)) {
zswap_folio_swapin(folio);
swap_read_folio(folio, false, NULL);
swap_read_folio(folio, NULL);
}
return folio;
}