From 74c74282c554f48f6a24b5050e486db5202fc1a2 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 17 Aug 2017 13:13:37 -0700 Subject: [PATCH] skd: Optimize locking Only take skdev->lock if necessary. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/block/skd_main.c | 21 +++++++++++++++------ 1 file 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, -- 2.20.1