Searched hist:"01 e99aeca3979600302913cef3f89076786f32c8" (Results 1 – 4 of 4) sorted by relevance
/openbmc/linux/block/ |
H A D | blk-mq-sched.c | diff 01e99aeca3979600302913cef3f89076786f32c8 Mon Feb 24 19:04:32 CST 2020 Ming Lei <ming.lei@redhat.com> blk-mq: insert passthrough request into hctx->dispatch directly
For some reason, device may be in one situation which can't handle FS request, so STS_RESOURCE is always returned and the FS request will be added to hctx->dispatch. However passthrough request may be required at that time for fixing the problem. If passthrough request is added to scheduler queue, there isn't any chance for blk-mq to dispatch it given we prioritize requests in hctx->dispatch. Then the FS IO request may never be completed, and IO hang is caused.
So passthrough request has to be added to hctx->dispatch directly for fixing the IO hang.
Fix this issue by inserting passthrough request into hctx->dispatch directly together withing adding FS request to the tail of hctx->dispatch in blk_mq_dispatch_rq_list(). Actually we add FS request to tail of hctx->dispatch at default, see blk_mq_request_bypass_insert().
Then it becomes consistent with original legacy IO request path, in which passthrough request is always added to q->queue_head.
Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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H A D | blk-flush.c | diff 01e99aeca3979600302913cef3f89076786f32c8 Mon Feb 24 19:04:32 CST 2020 Ming Lei <ming.lei@redhat.com> blk-mq: insert passthrough request into hctx->dispatch directly
For some reason, device may be in one situation which can't handle FS request, so STS_RESOURCE is always returned and the FS request will be added to hctx->dispatch. However passthrough request may be required at that time for fixing the problem. If passthrough request is added to scheduler queue, there isn't any chance for blk-mq to dispatch it given we prioritize requests in hctx->dispatch. Then the FS IO request may never be completed, and IO hang is caused.
So passthrough request has to be added to hctx->dispatch directly for fixing the IO hang.
Fix this issue by inserting passthrough request into hctx->dispatch directly together withing adding FS request to the tail of hctx->dispatch in blk_mq_dispatch_rq_list(). Actually we add FS request to tail of hctx->dispatch at default, see blk_mq_request_bypass_insert().
Then it becomes consistent with original legacy IO request path, in which passthrough request is always added to q->queue_head.
Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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H A D | blk-mq.h | diff 01e99aeca3979600302913cef3f89076786f32c8 Mon Feb 24 19:04:32 CST 2020 Ming Lei <ming.lei@redhat.com> blk-mq: insert passthrough request into hctx->dispatch directly
For some reason, device may be in one situation which can't handle FS request, so STS_RESOURCE is always returned and the FS request will be added to hctx->dispatch. However passthrough request may be required at that time for fixing the problem. If passthrough request is added to scheduler queue, there isn't any chance for blk-mq to dispatch it given we prioritize requests in hctx->dispatch. Then the FS IO request may never be completed, and IO hang is caused.
So passthrough request has to be added to hctx->dispatch directly for fixing the IO hang.
Fix this issue by inserting passthrough request into hctx->dispatch directly together withing adding FS request to the tail of hctx->dispatch in blk_mq_dispatch_rq_list(). Actually we add FS request to tail of hctx->dispatch at default, see blk_mq_request_bypass_insert().
Then it becomes consistent with original legacy IO request path, in which passthrough request is always added to q->queue_head.
Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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H A D | blk-mq.c | diff 01e99aeca3979600302913cef3f89076786f32c8 Mon Feb 24 19:04:32 CST 2020 Ming Lei <ming.lei@redhat.com> blk-mq: insert passthrough request into hctx->dispatch directly
For some reason, device may be in one situation which can't handle FS request, so STS_RESOURCE is always returned and the FS request will be added to hctx->dispatch. However passthrough request may be required at that time for fixing the problem. If passthrough request is added to scheduler queue, there isn't any chance for blk-mq to dispatch it given we prioritize requests in hctx->dispatch. Then the FS IO request may never be completed, and IO hang is caused.
So passthrough request has to be added to hctx->dispatch directly for fixing the IO hang.
Fix this issue by inserting passthrough request into hctx->dispatch directly together withing adding FS request to the tail of hctx->dispatch in blk_mq_dispatch_rq_list(). Actually we add FS request to tail of hctx->dispatch at default, see blk_mq_request_bypass_insert().
Then it becomes consistent with original legacy IO request path, in which passthrough request is always added to q->queue_head.
Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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