From: Jens Axboe <axboe@kernel.dk>
To: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>,
linux-nvme@lists.infradead.org
Cc: kbusch@kernel.org, hch@lst.de, sagi@grimberg.me
Subject: Re: [PATCH 1/2] nvme-pci; remove the barriers nvme_irq()
Date: Fri, 19 Feb 2021 06:40:04 -0700 [thread overview]
Message-ID: <80fc53d2-4f35-7c72-5cc5-3ec13c5ee51a@kernel.dk> (raw)
In-Reply-To: <20210219063726.63728-1-chaitanya.kulkarni@wdc.com>
On 2/18/21 11:37 PM, Chaitanya Kulkarni wrote:
> The barriers were added to the nvme_irq() in the
> commit 3a7afd8ee42a ("nvme-pci: remove the CQ lock for interrupt driven queues")
> to prevent compiler from doing memory optimization for the variabes that
> were protected previously by spinlock in nvme_irq() at completion queue
> processing and with queue head check condition..
>
> The variable nvmeq->last_cq_head from those checks was removed in the
> commit f6c4d97b0d82 ("nvme/pci: Remove last_cq_head")") that was
> preventing poll queues from mistakenly triggering the spurious
> interrupt detection.
>
> Remove the barriers which were protecting the updates to the variables.
Would seem prudent to just ask the original submitter to send a v2
of his patch, as that's where it came from.
--
Jens Axboe
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
next prev parent reply other threads:[~2021-02-19 13:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-19 6:37 [PATCH 1/2] nvme-pci; remove the barriers nvme_irq() Chaitanya Kulkarni
2021-02-19 13:40 ` Jens Axboe [this message]
2021-02-23 6:54 ` Chaitanya Kulkarni
2021-02-23 14:36 ` Heiner Kallweit
2021-02-23 20:49 ` Chaitanya Kulkarni
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=80fc53d2-4f35-7c72-5cc5-3ec13c5ee51a@kernel.dk \
--to=axboe@kernel.dk \
--cc=chaitanya.kulkarni@wdc.com \
--cc=hch@lst.de \
--cc=kbusch@kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=sagi@grimberg.me \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox