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| author | NeilBrown <neilb@suse.de> | 2022-05-09 18:20:48 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-05-09 18:20:48 -0700 |
| commit | d791ea676b66489ef6dabd04cd655f5c77426e40 (patch) | |
| tree | 8560739409e33c8db7aee3a690f5d0dd09231833 /mm/swap.h | |
| parent | 4b60c0ff2f2021ab99b7fb9da63b7ed1579ef1d8 (diff) | |
| download | linux-d791ea676b66489ef6dabd04cd655f5c77426e40.tar.gz linux-d791ea676b66489ef6dabd04cd655f5c77426e40.tar.bz2 linux-d791ea676b66489ef6dabd04cd655f5c77426e40.zip | |
mm: reclaim mustn't enter FS for SWP_FS_OPS swap-space
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variable becoming out-of-date.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>
Diffstat (limited to 'mm/swap.h')
| -rw-r--r-- | mm/swap.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/swap.h b/mm/swap.h index f8265bf0ce00..e19f185df5e2 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -50,6 +50,10 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, struct vm_fault *vmf); +static inline unsigned int page_swap_flags(struct page *page) +{ + return page_swap_info(page)->flags; +} #else /* CONFIG_SWAP */ static inline int swap_readpage(struct page *page, bool do_poll) { @@ -129,5 +133,9 @@ static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, { } +static inline unsigned int page_swap_flags(struct page *page) +{ + return 0; +} #endif /* CONFIG_SWAP */ #endif /* _MM_SWAP_H */ |