Use the new REQ_ZWPLUG_UNORDERED bio flag so that even copies to sequential write required zones can queue up writes bios as soon as the reads finish. This simplifies the code and reduces the submission latency as all writes are immediately available in the zoned write plug list when the previous write completes instead of going through two layers of queueing.
Signed-off-by: Christoph Hellwig <[email protected]> --- drivers/md/dm-kcopyd.c | 48 ++++++------------------------------------ 1 file changed, 6 insertions(+), 42 deletions(-) diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c index 6ea75436a433..37e181c79760 100644 --- a/drivers/md/dm-kcopyd.c +++ b/drivers/md/dm-kcopyd.c @@ -383,7 +383,6 @@ struct kcopyd_job { struct mutex lock; atomic_t sub_jobs; sector_t progress; - sector_t write_offset; struct kcopyd_job *master_job; }; @@ -411,50 +410,17 @@ void dm_kcopyd_exit(void) } /* - * Functions to push and pop a job onto the head of a given job - * list. + * Functions to push and pop a job onto the head of a given job list. */ -static struct kcopyd_job *pop_io_job(struct list_head *jobs, - struct dm_kcopyd_client *kc) -{ - struct kcopyd_job *job; - - /* - * For I/O jobs, pop any read, any write without sequential write - * constraint and sequential writes that are at the right position. - */ - list_for_each_entry(job, jobs, list) { - if (job->op == REQ_OP_READ || - !(job->flags & BIT(DM_KCOPYD_WRITE_SEQ))) { - list_del(&job->list); - return job; - } - - if (job->write_offset == job->master_job->write_offset) { - job->master_job->write_offset += job->source.count; - list_del(&job->list); - return job; - } - } - - return NULL; -} - static struct kcopyd_job *pop(struct list_head *jobs, struct dm_kcopyd_client *kc) { struct kcopyd_job *job = NULL; spin_lock_irq(&kc->job_lock); - - if (!list_empty(jobs)) { - if (jobs == &kc->io_jobs) - job = pop_io_job(jobs, kc); - else { - job = list_entry(jobs->next, struct kcopyd_job, list); - list_del(&job->list); - } - } + job = list_first_entry_or_null(jobs, struct kcopyd_job, list); + if (job) + list_del(&job->list); spin_unlock_irq(&kc->job_lock); return job; @@ -541,7 +507,7 @@ static void complete_io(unsigned long error, void *context) push(&kc->complete_jobs, job); else { - job->op = REQ_OP_WRITE; + job->op = REQ_OP_WRITE | REQ_ZWPLUG_UNORDERED; push(&kc->io_jobs, job); } @@ -730,7 +696,6 @@ static void segment_complete(int read_err, unsigned long write_err, int i; *sub_job = *job; - sub_job->write_offset = progress; sub_job->source.sector += progress; sub_job->source.count = count; @@ -833,7 +798,7 @@ void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, /* * Use WRITE ZEROES to optimize zeroing if all dests support it. */ - job->op = REQ_OP_WRITE_ZEROES; + job->op = REQ_OP_WRITE_ZEROES | REQ_ZWPLUG_UNORDERED; for (i = 0; i < job->num_dests; i++) if (!bdev_write_zeroes_sectors(job->dests[i].bdev)) { job->op = REQ_OP_WRITE; @@ -844,7 +809,6 @@ void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, job->fn = fn; job->context = context; job->master_job = job; - job->write_offset = 0; if (job->source.count <= kc->sub_job_size) dispatch_job(job); -- 2.47.3
