| Message ID | 20220304160331.399757-2-hch@lst.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [01/14] blk-mq: do not include passthrough requests in I/O accounting | expand |
On 3/4/22 08:03, Christoph Hellwig wrote: > I/O accounting buckets I/O into the read/write/discard categories into > which passthrough I/O does not fit at all. It also accounts to the > block_device, which may not even exist for passthrough I/O. Reviewed-by: Bart Van Assche <bvanassche@acm.org>
On 3/4/22 08:03, Christoph Hellwig wrote: > I/O accounting buckets I/O into the read/write/discard categories into > which passthrough I/O does not fit at all. It also accounts to the > block_device, which may not even exist for passthrough I/O. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- Looks good. Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Christoph, > I/O accounting buckets I/O into the read/write/discard categories into > which passthrough I/O does not fit at all. It also accounts to the > block_device, which may not even exist for passthrough I/O. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c index a05ce77250316..ab4b646551334 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -883,10 +883,15 @@ static inline void blk_account_io_done(struct request *req, u64 now) static void __blk_account_io_start(struct request *rq) { - /* passthrough requests can hold bios that do not have ->bi_bdev set */ - if (rq->bio && rq->bio->bi_bdev) + /* + * All non-passthrough requests are created from a bio with one + * exception: when a flush command that is part of a flush sequence + * generated by the state machine in blk-flush.c is cloned onto the + * lower device by dm-multipath we can get here without a bio. + */ + if (rq->bio) rq->part = rq->bio->bi_bdev; - else if (rq->q->disk) + else rq->part = rq->q->disk->part0; part_stat_lock(); diff --git a/block/blk.h b/block/blk.h index ebaa59ca46ca6..6f21859c7f0ff 100644 --- a/block/blk.h +++ b/block/blk.h @@ -325,7 +325,7 @@ int blk_dev_init(void); */ static inline bool blk_do_io_stat(struct request *rq) { - return (rq->rq_flags & RQF_IO_STAT) && rq->q->disk; + return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq); } void update_io_ticks(struct block_device *part, unsigned long now, bool end);
I/O accounting buckets I/O into the read/write/discard categories into which passthrough I/O does not fit at all. It also accounts to the block_device, which may not even exist for passthrough I/O. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-mq.c | 11 ++++++++--- block/blk.h | 2 +- 2 files changed, 9 insertions(+), 4 deletions(-)