From: Christoph Hellwig <hch@lst.de>
To: Sagi Grimberg <sagi@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>
Subject: Re: [PATCH] nvme-pci: silence a lockdep complaint
Date: Thu, 23 May 2024 14:39:49 +0200 [thread overview]
Message-ID: <20240523123949.GA20758@lst.de> (raw)
In-Reply-To: <a643075c-a51a-413a-a0a0-7954049ad918@grimberg.me>
On Thu, May 23, 2024 at 01:04:13PM +0300, Sagi Grimberg wrote:
>
>
> On 23/05/2024 9:54, Christoph Hellwig wrote:
>> On Wed, May 22, 2024 at 03:36:19PM -0600, Keith Busch wrote:
>>> The below patch is what I'm messing with. I have a CMIC PCI NVMe and
>>> nvme native multipathing enabled, and that can recreate the lockdep
>>> splat 100% of the time. It goes away with this patch. Non-multipath
>>> devices are harder to hit the lockdep splat for a different reason.
>> I much prefer the srcu locking as it has real benefits as well over
>> a global-ish rwsem. I'll try to get to a real review in a bit.
>>
>
> Can you explain what are these benefits?
No having a global lock taken for namespace lookups.
next prev parent reply other threads:[~2024-05-23 12:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-22 9:15 [PATCH] nvme-pci: silence a lockdep complaint Sagi Grimberg
2024-05-22 12:18 ` Shinichiro Kawasaki
2024-05-22 16:12 ` Keith Busch
2024-05-22 16:28 ` Christoph Hellwig
2024-05-22 18:00 ` Sagi Grimberg
2024-05-22 21:36 ` Keith Busch
2024-05-23 6:54 ` Christoph Hellwig
2024-05-23 10:04 ` Sagi Grimberg
2024-05-23 12:39 ` Christoph Hellwig [this message]
2024-05-23 13:02 ` Sagi Grimberg
2024-05-23 13:19 ` Christoph Hellwig
2024-05-23 13:45 ` Sagi Grimberg
2024-05-23 15:02 ` Keith Busch
2024-05-23 8:06 ` Christoph Hellwig
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=20240523123949.GA20758@lst.de \
--to=hch@lst.de \
--cc=kbusch@kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=sagi@grimberg.me \
--cc=shinichiro.kawasaki@wdc.com \
/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