From: Al Viro <viro@zeniv.linux.org.uk>
To: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Eric Biggers <ebiggers@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
"Theodore Y. Ts'o" <tytso@mit.edu>,
Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <yuchao0@huawei.com>,
Tyler Hicks <tyhicks@canonical.com>,
linux-fsdevel@vger.kernel.org, ecryptfs@vger.kernel.org,
linux-fscrypt@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5] fs: introduce is_dot_or_dotdot helper for cleanup
Date: Wed, 11 Dec 2019 04:47:23 +0000 [thread overview]
Message-ID: <20191211044723.GC4203@ZenIV.linux.org.uk> (raw)
In-Reply-To: <febbd7eb-5e53-6e7c-582d-5b224e441e37@loongson.cn>
On Wed, Dec 11, 2019 at 11:59:40AM +0800, Tiezhu Yang wrote:
> static inline bool is_dot_or_dotdot(const unsigned char *name, size_t len)
> {
> if (len == 1 && name[0] == '.')
> return true;
>
> if (len == 2 && name[0] == '.' && name[1] == '.')
> return true;
>
> return false;
> }
>
> Hi Matthew,
>
> How do you think? I think the performance influence is very small
> due to is_dot_or_dotdot() is a such short static inline function.
It's a very short inline function called on a very hot codepath.
Often.
I mean it - it's done literally for every pathname component of
every pathname passed to a syscall.
WARNING: multiple messages have this Message-ID (diff)
From: Al Viro <viro@zeniv.linux.org.uk>
To: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: ecryptfs@vger.kernel.org, "Theodore Y. Ts'o" <tytso@mit.edu>,
linux-kernel@vger.kernel.org,
Matthew Wilcox <willy@infradead.org>,
Tyler Hicks <tyhicks@canonical.com>,
Eric Biggers <ebiggers@kernel.org>,
linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Jaegeuk Kim <jaegeuk@kernel.org>,
linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [f2fs-dev] [PATCH v5] fs: introduce is_dot_or_dotdot helper for cleanup
Date: Wed, 11 Dec 2019 04:47:23 +0000 [thread overview]
Message-ID: <20191211044723.GC4203@ZenIV.linux.org.uk> (raw)
In-Reply-To: <febbd7eb-5e53-6e7c-582d-5b224e441e37@loongson.cn>
On Wed, Dec 11, 2019 at 11:59:40AM +0800, Tiezhu Yang wrote:
> static inline bool is_dot_or_dotdot(const unsigned char *name, size_t len)
> {
> if (len == 1 && name[0] == '.')
> return true;
>
> if (len == 2 && name[0] == '.' && name[1] == '.')
> return true;
>
> return false;
> }
>
> Hi Matthew,
>
> How do you think? I think the performance influence is very small
> due to is_dot_or_dotdot() is a such short static inline function.
It's a very short inline function called on a very hot codepath.
Often.
I mean it - it's done literally for every pathname component of
every pathname passed to a syscall.
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
next prev parent reply other threads:[~2019-12-11 4:47 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-11 2:20 [PATCH v5] fs: introduce is_dot_or_dotdot helper for cleanup Tiezhu Yang
2019-12-11 2:20 ` [f2fs-dev] " Tiezhu Yang
2019-12-11 2:48 ` Eric Biggers
2019-12-11 2:48 ` [f2fs-dev] " Eric Biggers
2019-12-11 3:59 ` Tiezhu Yang
2019-12-11 3:59 ` [f2fs-dev] " Tiezhu Yang
2019-12-11 4:47 ` Al Viro [this message]
2019-12-11 4:47 ` Al Viro
2019-12-11 6:38 ` Tiezhu Yang
2019-12-11 6:38 ` Tiezhu Yang
2019-12-11 6:38 ` [f2fs-dev] " Tiezhu Yang
2019-12-11 7:17 ` Gao Xiang
2019-12-11 7:17 ` Gao Xiang
2019-12-11 7:17 ` [f2fs-dev] " Gao Xiang
2019-12-11 13:40 ` Matthew Wilcox
2019-12-11 13:40 ` [f2fs-dev] " Matthew Wilcox
2019-12-11 14:41 ` Gao Xiang
2019-12-11 14:41 ` [f2fs-dev] " Gao Xiang via Linux-f2fs-devel
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=20191211044723.GC4203@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=ebiggers@kernel.org \
--cc=ecryptfs@vger.kernel.org \
--cc=jaegeuk@kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-fscrypt@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tyhicks@canonical.com \
--cc=tytso@mit.edu \
--cc=willy@infradead.org \
--cc=yangtiezhu@loongson.cn \
--cc=yuchao0@huawei.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.