diff options
| author | Christoph Hellwig <hch@lst.de> | 2020-04-28 13:27:54 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-04-29 17:33:26 +0200 |
| commit | 760f83ea63a7b2c12b3b1e656b24cbb880b6b814 (patch) | |
| tree | d66373dc8dac91571a6ff854e4b6eedc7faeb69f /block/blk-core.c | |
| parent | block: improve the submit_bio and generic_make_request documentation (diff) | |
| download | linux-760f83ea63a7b2c12b3b1e656b24cbb880b6b814.tar.xz linux-760f83ea63a7b2c12b3b1e656b24cbb880b6b814.zip | |
block: cleanup the memory stall accounting in submit_bio
Instead of a convoluted chain just check for REQ_OP_READ directly,
and keep all the memory stall code together in a single unlikely
branch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 30 |
1 files changed, 14 insertions, 16 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 68351ee94ad2..81a291085c6c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1148,10 +1148,6 @@ EXPORT_SYMBOL_GPL(direct_make_request); */ blk_qc_t submit_bio(struct bio *bio) { - bool workingset_read = false; - unsigned long pflags; - blk_qc_t ret; - if (blkcg_punt_bio_submit(bio)) return BLK_QC_T_NONE; @@ -1170,8 +1166,6 @@ blk_qc_t submit_bio(struct bio *bio) if (op_is_write(bio_op(bio))) { count_vm_events(PGPGOUT, count); } else { - if (bio_flagged(bio, BIO_WORKINGSET)) - workingset_read = true; task_io_account_read(bio->bi_iter.bi_size); count_vm_events(PGPGIN, count); } @@ -1187,20 +1181,24 @@ blk_qc_t submit_bio(struct bio *bio) } /* - * If we're reading data that is part of the userspace - * workingset, count submission time as memory stall. When the - * device is congested, or the submitting cgroup IO-throttled, - * submission can be a significant part of overall IO time. + * If we're reading data that is part of the userspace workingset, count + * submission time as memory stall. When the device is congested, or + * the submitting cgroup IO-throttled, submission can be a significant + * part of overall IO time. */ - if (workingset_read) - psi_memstall_enter(&pflags); - - ret = generic_make_request(bio); + if (unlikely(bio_op(bio) == REQ_OP_READ && + bio_flagged(bio, BIO_WORKINGSET))) { + unsigned long pflags; + blk_qc_t ret; - if (workingset_read) + psi_memstall_enter(&pflags); + ret = generic_make_request(bio); psi_memstall_leave(&pflags); - return ret; + return ret; + } + + return generic_make_request(bio); } EXPORT_SYMBOL(submit_bio); |