From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH 3/7] nvme-pci: remove cq check after submission
Date: Thu, 17 May 2018 18:31:48 +0200 [thread overview]
Message-ID: <20180517163152.23155-4-hch@lst.de> (raw)
In-Reply-To: <20180517163152.23155-1-hch@lst.de>
From: Jens Axboe <axboe@kernel.dk>
We always check the completion queue after submitting, but in my testing
this isn't a win even on DRAM/xpoint devices. In some cases it's
actually worse. Kill it.
Signed-off-by: Jens Axboe <axboe at kernel.dk>
Signed-off-by: Keith Busch <keith.busch at intel.com>
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
drivers/nvme/host/pci.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 4b8c3420ace6..16eacae3b69d 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -69,7 +69,6 @@ MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
struct nvme_dev;
struct nvme_queue;
-static void nvme_process_cq(struct nvme_queue *nvmeq);
static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
/*
@@ -896,7 +895,6 @@ static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
goto out_cleanup_iod;
}
__nvme_submit_cmd(nvmeq, &cmnd);
- nvme_process_cq(nvmeq);
spin_unlock_irq(&nvmeq->q_lock);
return BLK_STS_OK;
out_cleanup_iod:
--
2.17.0
next prev parent reply other threads:[~2018-05-17 16:31 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-17 16:31 RFC: handle completions outside the queue lock and split the queue lock Christoph Hellwig
2018-05-17 16:31 ` [PATCH 1/7] nvme: mark the result argument to nvme_complete_async_event volatile Christoph Hellwig
2018-05-17 16:31 ` [PATCH 2/7] nvme-pci: simplify nvme_cqe_valid Christoph Hellwig
2018-05-17 16:31 ` Christoph Hellwig [this message]
2018-05-17 16:31 ` [PATCH 4/7] nvme-pci: move ->cq_vector == -1 check outside of ->q_lock Christoph Hellwig
2018-05-17 16:31 ` [PATCH 5/7] nvme-pci: handle completions outside of the queue lock Christoph Hellwig
2018-05-17 16:31 ` [PATCH 6/7] nvme-pci: split the nvme queue lock into submission and completion locks Christoph Hellwig
2018-05-17 16:31 ` [PATCH 7/7] nvme-pci: drop IRQ disabling on submission queue lock Christoph Hellwig
2018-05-17 16:36 ` RFC: handle completions outside the queue lock and split the " Jens Axboe
2018-05-17 16:44 ` Christoph Hellwig
2018-05-17 16:55 ` Keith Busch
2018-05-17 17:00 ` Christoph Hellwig
2018-05-17 17:05 ` Keith Busch
2018-05-17 17:08 ` Jens Axboe
2018-05-18 14:52 [PATCHSET v2 0/7] Improve nvme completion handling Jens Axboe
2018-05-18 14:52 ` [PATCH 3/7] nvme-pci: remove cq check after submission Jens Axboe
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