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| author | NeilBrown <neilb@suse.de> | 2022-05-10 04:20:49 +0300 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-05-10 04:20:49 +0300 |
| commit | 2282679fb20bf036a714ed49fadd0230c278a203 (patch) | |
| tree | 9d800e63a82d3405fd1897ab4b8e3873d7ebb561 /mm/swap.h | |
| parent | 5169b844b7dd5934cd4f22ab66de0cc669abf0b0 (diff) | |
| download | linux-2282679fb20bf036a714ed49fadd0230c278a203.tar.xz | |
mm: submit multipage write for SWP_FS_OPS swap-space
swap_writepage() is given one page at a time, but may be called repeatedly
in succession.
For block-device swapspace, the blk_plug functionality allows the multiple
pages to be combined together at lower layers. That cannot be used for
SWP_FS_OPS as blk_plug may not exist - it is only active when
CONFIG_BLOCK=y. Consequently all swap reads over NFS are single page
reads.
With this patch we pass a pointer-to-pointer via the wbc. swap_writepage
can store state between calls - much like the pointer passed explicitly to
swap_readpage. After calling swap_writepage() some number of times, the
state will be passed to swap_write_unplug() which can submit the combined
request.
Link: https://lkml.kernel.org/r/164859778128.29473.5191868522654408537.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 | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/swap.h b/mm/swap.h index 0389ab147837..a6da8f612904 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -16,6 +16,7 @@ static inline void swap_read_unplug(struct swap_iocb *plug) if (unlikely(plug)) __swap_read_unplug(plug); } +void swap_write_unplug(struct swap_iocb *sio); int swap_writepage(struct page *page, struct writeback_control *wbc); void end_swap_bio_write(struct bio *bio); int __swap_writepage(struct page *page, struct writeback_control *wbc, @@ -71,6 +72,9 @@ static inline int swap_readpage(struct page *page, bool do_poll, { return 0; } +static inline void swap_write_unplug(struct swap_iocb *sio) +{ +} static inline struct address_space *swap_address_space(swp_entry_t entry) { |