From: Andi Kleen <ak@suse.de>
To: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: David Miller <davem@davemloft.net>,
Ulrich Drepper <drepper@redhat.com>,
Andrew Morton <akpm@osdl.org>, netdev <netdev@vger.kernel.org>,
Zach Brown <zach.brown@oracle.com>,
Christoph Hellwig <hch@infradead.org>,
Chase Venters <chase.venters@clientec.com>,
Johann Borck <johann.borck@densedata.com>,
linux-kernel@vger.kernel.org, Jeff Garzik <jeff@garzik.org>,
Jamal Hadi Salim <hadi@cyberus.ca>, Ingo Molnar <mingo@elte.hu>,
linux-fsdevel@vger.kernel.org
Subject: Re: [take36 10/10] kevent: Kevent based generic AIO.
Date: 12 Feb 2007 14:08:10 +0100 [thread overview]
Message-ID: <p733b5bh6bp.fsf@bingen.suse.de> (raw)
In-Reply-To: <1171279650540@2ka.mipt.ru>
Evgeniy Polyakov <johnpol@2ka.mipt.ru> writes:
>
> aio_sendfile_path() is essentially aio_sendfile(), except that it takes
> source filename as parameter, has a pointer to private header
> and its size (which allows to send header and file's content in one syscall
> instead of three (open, send, sendfile) and returns opened file descriptor.
Are you sure this is a useful optimization? Do you have numbers vs open+aio_sendfile+close?
Compared to the cost of sending a complete file three system calls should be quite in the noise.
And Linux system calls are not that expensive (few hundred cycles normally)
Adding such compound system calls would be a worrying precedent because
I'm sure others would want them then for their favourite system call combo
too. If they were really useful it might make more sense to have a batch()
system call that works for arbitary calls, but I'm not convinced yet
it's even needed. It would be certainly ugly.
-Andi
next prev parent reply other threads:[~2007-02-12 12:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <11712796473213@2ka.mipt.ru>
2007-02-12 11:27 ` [take36 3/10] kevent: poll/select() notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 4/10] kevent: Socket notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 5/10] kevent: Timer notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 6/10] kevent: Pipe notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 7/10] kevent: Signal notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 8/10] kevent: Kevent posix timer notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 9/10] kevent: Private userspace notifications Evgeniy Polyakov
2007-02-12 11:27 ` [take36 10/10] kevent: Kevent based generic AIO Evgeniy Polyakov
2007-02-12 13:08 ` Andi Kleen [this message]
2007-02-12 12:19 ` Evgeniy Polyakov
2007-02-12 13:12 ` Alan
2007-02-12 13:24 ` Evgeniy Polyakov
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=p733b5bh6bp.fsf@bingen.suse.de \
--to=ak@suse.de \
--cc=akpm@osdl.org \
--cc=chase.venters@clientec.com \
--cc=davem@davemloft.net \
--cc=drepper@redhat.com \
--cc=hadi@cyberus.ca \
--cc=hch@infradead.org \
--cc=jeff@garzik.org \
--cc=johann.borck@densedata.com \
--cc=johnpol@2ka.mipt.ru \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=netdev@vger.kernel.org \
--cc=zach.brown@oracle.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.