Re: [PATCH] nvme: use lighter smp barriers in nvme_irq
From: Keith Busch <kbusch@kernel.org>
Date: 2021-02-18 21:58:41
On Thu, Feb 18, 2021 at 04:06:35AM +0000, Chaitanya Kulkarni wrote:
On 2/17/21 19:28, Keith Busch wrote:quoted
The variables the driver was protecting no longer exist, so I also agree the barriers should not be necessary.Are you saying something like following is needed ?
Right, I'm just saying the barriers don't appear to be necessary, so they can go away as you've indicated below.
quoted hunk ↗ jump to hunk
From a3a73bd3943b479f82ff00582baf2c37c1afd8e8 Mon Sep 17 00:00:00 2001 From: Chaitanya Kulkarni <redacted> Date: Wed, 17 Feb 2021 20:01:37 -0800 Subject: [PATCH] nvme-pci: remove the barriers The variable which was protected by the barriers is removed in The commit f6c4d97b0d82 (" nvme/pci: Remove last_cq_head"). Remove the barriers which was protecting the variable. Signed-off-by: Chaitanya Kulkarni <redacted> --- drivers/nvme/host/pci.c | 6 ------ 1 file changed, 6 deletions(-)diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 0045c5edf629..3729775f6a8a 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c@@ -1062,14 +1062,8 @@ static irqreturn_t nvme_irq(int irq, void *data) struct nvme_queue *nvmeq = data; irqreturn_t ret = IRQ_NONE; - /* - * The rmb/wmb pair ensures we see all updates from a previous run of - * the irq handler, even if that was on another CPU. - */ - rmb(); if (nvme_process_cq(nvmeq)) ret = IRQ_HANDLED; - wmb(); return ret; }-- 2.22.1
_______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme