From: Andrew Morton <akpm@osdl.org>
To: Jan Blunck <j.blunck@tu-harburg.de>
Cc: torvalds@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH][RESEND] don't allow sys_readahead() on files opened with O_DIRECT
Date: Thu, 25 Aug 2005 01:24:40 -0700 [thread overview]
Message-ID: <20050825012440.66b61cca.akpm@osdl.org> (raw)
In-Reply-To: <4305D437.4000703@tu-harburg.de>
Jan Blunck <j.blunck@tu-harburg.de> wrote:
>
> IMO sys_readahead() doesn't make sense if the file is opened with
> O_DIRECT, because the page cache is stuffed but never used. Therefore
> this patch changes that by letting the call return with -EINVAL.
>
a) It doesn't hurt, it's just a bit of a silly thing to do.
b) posix_fadvise(POSIX_FADV_WILLNEED) should get the same treatment (and
it's the preferred way of doing readahead).
c) O_DIRECT fd's should, as much as possible, offer the same ABI as
buffered fd's.
d) The patch could break existing apps.
next prev parent reply other threads:[~2005-08-25 8:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-19 12:44 [PATCH][RESEND] don't allow sys_readahead() on files opened with O_DIRECT Jan Blunck
2005-08-25 8:24 ` Andrew Morton [this message]
2005-08-25 12:13 ` Jan Blunck
2005-08-25 12:46 ` Christoph Hellwig
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=20050825012440.66b61cca.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=j.blunck@tu-harburg.de \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@osdl.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 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.