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| author | Ming Lei <ming.lei@redhat.com> | 2022-04-20 16:31:10 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-05-02 18:07:42 +0200 |
| commit | 9650b453a3d4b1b8ed4ea8bcb9b40109608d1faf (patch) | |
| tree | c43dfc5033aec249e22536898a6a043390df7782 /mm/page_io.c | |
| parent | block/partitions/ldm: Remove redundant assignments (diff) | |
| download | linux-9650b453a3d4b1b8ed4ea8bcb9b40109608d1faf.tar.xz linux-9650b453a3d4b1b8ed4ea8bcb9b40109608d1faf.zip | |
block: ignore RWF_HIPRI hint for sync dio
So far bio is marked as REQ_POLLED if RWF_HIPRI/IOCB_HIPRI is passed
from userspace sync io interface, then block layer tries to poll until
the bio is completed. But the current implementation calls
blk_io_schedule() if bio_poll() returns 0, and this way causes io hang or
timeout easily.
But looks no one reports this kind of issue, which should have been
triggered in normal io poll sanity test or blktests block/007 as
observed by Changhui, that means it is very likely that no one uses it
or no one cares it.
Also after io_uring is invented, io poll for sync dio becomes legacy
interface.
So ignore RWF_HIPRI hint for sync dio.
CC: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Reported-by: Changhui Zhong <czhong@redhat.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Changhui Zhong <czhong@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220420143110.2679002-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'mm/page_io.c')
| -rw-r--r-- | mm/page_io.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/mm/page_io.c b/mm/page_io.c index 89fbf3cae30f..3fbdab6a940e 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -360,7 +360,6 @@ int swap_readpage(struct page *page, bool synchronous) * attempt to access it in the page fault retry time check. */ if (synchronous) { - bio->bi_opf |= REQ_POLLED; get_task_struct(current); bio->bi_private = current; } @@ -372,8 +371,7 @@ int swap_readpage(struct page *page, bool synchronous) if (!READ_ONCE(bio->bi_private)) break; - if (!bio_poll(bio, NULL, 0)) - blk_io_schedule(); + blk_io_schedule(); } __set_current_state(TASK_RUNNING); bio_put(bio); |