BPF Archive on lore.kernel.org
 help / color / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: Muchun Song <songmuchun@bytedance.com>
Cc: adobriyan@gmail.com, ast@kernel.org, daniel@iogearbox.net,
	kafai@fb.com, songliubraving@fb.com, yhs@fb.com, andriin@fb.com,
	john.fastabend@gmail.com, kpsingh@chromium.org,
	ebiederm@xmission.com, bernd.edlinger@hotmail.de,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH] files: Use rcu lock to get the file structures for better performance
Date: Thu, 21 May 2020 08:21:17 -0700
Message-ID: <20200521152117.GC28818@bombadil.infradead.org> (raw)
In-Reply-To: <20200521123835.70069-1-songmuchun@bytedance.com>

On Thu, May 21, 2020 at 08:38:35PM +0800, Muchun Song wrote:
> There is another safe way to get the file structure without
> holding the files->file_lock. That is rcu lock, and this way
> has better performance. So use the rcu lock instead of the
> files->file_lock.

What makes you think this is safe?  Are you actually seeing contention
on this spinlock?

  reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 12:38 Muchun Song
2020-05-21 15:21 ` Matthew Wilcox [this message]
2020-05-21 16:06   ` [External] " Muchun Song
2020-05-21 16:16     ` Greg KH
2020-05-21 16:47 ` Matthew Wilcox
2020-05-22  7:52   ` [External] " Muchun Song
2020-05-22 11:43     ` Matthew Wilcox

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200521152117.GC28818@bombadil.infradead.org \
    --to=willy@infradead.org \
    --cc=adobriyan@gmail.com \
    --cc=andriin@fb.com \
    --cc=ast@kernel.org \
    --cc=bernd.edlinger@hotmail.de \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=ebiederm@xmission.com \
    --cc=john.fastabend@gmail.com \
    --cc=kafai@fb.com \
    --cc=kpsingh@chromium.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=songliubraving@fb.com \
    --cc=songmuchun@bytedance.com \
    --cc=yhs@fb.com \


* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

BPF Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/bpf/0 bpf/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 bpf bpf/ https://lore.kernel.org/bpf \
	public-inbox-index bpf

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git