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| author | Bart Van Assche <bart.vanassche@wdc.com> | 2017-08-17 13:13:37 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-08-18 08:45:29 -0600 |
| commit | 74c74282c554f48f6a24b5050e486db5202fc1a2 (patch) | |
| tree | f83b8c993f5b6704b4d60dda26bbf56a8cadbde9 /drivers/block | |
| parent | e2bb5548279a95cf5b2ecc7cb070a743aade3445 (diff) | |
| download | linux-74c74282c554f48f6a24b5050e486db5202fc1a2.tar.gz linux-74c74282c554f48f6a24b5050e486db5202fc1a2.tar.bz2 linux-74c74282c554f48f6a24b5050e486db5202fc1a2.zip | |
skd: Optimize locking
Only take skdev->lock if necessary.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/skd_main.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c index a732bb8040f4..bcd8df0bf203 100644 --- a/drivers/block/skd_main.c +++ b/drivers/block/skd_main.c @@ -490,7 +490,7 @@ static void skd_process_request(struct request *req, bool last) const u32 tag = blk_mq_unique_tag(req); struct skd_request_context *const skreq = blk_mq_rq_to_pdu(req); struct skd_scsi_request *scsi_req; - unsigned long flags; + unsigned long flags = 0; const u32 lba = blk_rq_pos(req); const u32 count = blk_rq_sectors(req); const int data_dir = rq_data_dir(req); @@ -525,9 +525,13 @@ static void skd_process_request(struct request *req, bool last) sizeof(struct fit_sg_descriptor), DMA_TO_DEVICE); - spin_lock_irqsave(&skdev->lock, flags); /* Either a FIT msg is in progress or we have to start one. */ - skmsg = skdev->skmsg; + if (skd_max_req_per_msg == 1) { + skmsg = NULL; + } else { + spin_lock_irqsave(&skdev->lock, flags); + skmsg = skdev->skmsg; + } if (!skmsg) { skmsg = &skdev->skmsg_table[tag]; skdev->skmsg = skmsg; @@ -574,11 +578,16 @@ static void skd_process_request(struct request *req, bool last) /* * If the FIT msg buffer is full send it. */ - if (last || fmh->num_protocol_cmds_coalesced >= skd_max_req_per_msg) { + if (skd_max_req_per_msg == 1) { skd_send_fitmsg(skdev, skmsg); - skdev->skmsg = NULL; + } else { + if (last || + fmh->num_protocol_cmds_coalesced >= skd_max_req_per_msg) { + skd_send_fitmsg(skdev, skmsg); + skdev->skmsg = NULL; + } + spin_unlock_irqrestore(&skdev->lock, flags); } - spin_unlock_irqrestore(&skdev->lock, flags); } static blk_status_t skd_mq_queue_rq(struct blk_mq_hw_ctx *hctx, |