From: Christoph Hellwig <hch@infradead.org>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC/PATCH] Add preadv and pwritev system calls.
Date: Thu, 11 Dec 2008 18:49:08 -0500 [thread overview]
Message-ID: <20081211234908.GA11305@infradead.org> (raw)
In-Reply-To: <49419EA7.6050308@redhat.com>
On Fri, Dec 12, 2008 at 12:13:43AM +0100, Gerd Hoffmann wrote:
> Hi,
>
> The attached patch adds preadv and pwritev system calls. These syscalls
> are a pretty straightforward combination of pread and readv (same for
> write). They are quite useful for doing vectored I/O in threaded
> applications. Using lseek+readv instead opens race windows you'll have
> to plug with locking.
>
> Other systems have such system calls too, for example NetBSD, check
> here: http://www.daemon-systems.org/man/preadv.2.html
>
> The patch sports the actual system call implementation and the windup in
> the x86 system call tables. Other archs are TBD.
>
> Comments? Reviews? Suggestions? Flames?
Looks good, but you should Cc linux-arch so that arch maintainers get
a heads up to wire up the syscalls.
> + if (ret > 0)
> + add_rchar(current, ret);
> + inc_syscr(current);
> + return ret;
Could it be that these are missing for the compat case both for the existing
readv/writev and your new syscalls?
next prev parent reply other threads:[~2008-12-11 23:49 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-11 23:13 [RFC/PATCH] Add preadv and pwritev system calls Gerd Hoffmann
2008-12-11 23:49 ` Christoph Hellwig [this message]
2008-12-12 9:19 ` Gerd Hoffmann
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=20081211234908.GA11305@infradead.org \
--to=hch@infradead.org \
--cc=kraxel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
/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