From: Dominique Martinet <asmadeus@codewreck.org>
To: piaojun <piaojun@huawei.com>
Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
Eric Van Hensbergen <ericvh@gmail.com>,
Ron Minnich <rminnich@sandia.gov>,
Latchesar Ionkov <lucho@ionkov.net>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
v9fs-developer@lists.sourceforge.net
Subject: Re: [PATCH] net/9p/trans_virtio.c: replace mutex_lock with spin_lock to protect 'virtio_chan_list'
Date: Wed, 18 Jul 2018 11:54:20 +0200 [thread overview]
Message-ID: <20180718095420.GA28377@nautica> (raw)
In-Reply-To: <5B4EF511.7090104@huawei.com>
piaojun wrote on Wed, Jul 18, 2018:
> spin_lock is more effective for short time protection than mutex_lock, as
> mutex lock may cause process sleep and wake up which consume much cpu
> time.
That's not a fast path operation, I don't mind changing things but I'd
like to understand why - these functions are only ever called at unmount
time or when something happens on the virtio bus (probe will happen on
probing on the pci bus and I'm not too sure on remove but probably pci
removal i.e. basically never?)
I don't see why this wouldn't work, but I won't take this without a
(good?) reason.
--
Dominique Martinet
next prev parent reply other threads:[~2018-07-18 9:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 8:06 [PATCH] net/9p/trans_virtio.c: replace mutex_lock with spin_lock to protect 'virtio_chan_list' piaojun
2018-07-18 9:54 ` Dominique Martinet [this message]
2018-07-19 2:26 ` piaojun
2018-07-19 3:36 ` Dominique Martinet
2018-07-19 7:44 ` piaojun
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=20180718095420.GA28377@nautica \
--to=asmadeus@codewreck.org \
--cc=akpm@linux-foundation.org \
--cc=ericvh@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lucho@ionkov.net \
--cc=piaojun@huawei.com \
--cc=rminnich@sandia.gov \
--cc=v9fs-developer@lists.sourceforge.net \
/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;
as well as URLs for NNTP newsgroup(s).