From: Jeff Moyer <jmoyer@redhat.com>
To: Oliver Neukum <oliver@neukum.org>
Cc: GeunSik Lim <leemgs1@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: question on readahead and sync mounting
Date: Tue, 23 Feb 2010 12:38:44 -0500 [thread overview]
Message-ID: <x497hq34ztn.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <201002230059.09390.oliver@neukum.org> (Oliver Neukum's message of "Tue, 23 Feb 2010 00:59:09 +0100")
Oliver Neukum <oliver@neukum.org> writes:
> Am Dienstag, 23. Februar 2010 00:48:39 schrieben Sie:
>> Please, Refer to below articles to understand readahead essentially.
>>
>> http://lwn.net/Articles/235164/ (On-demand readahead by corbet)
>> http://kernelnewbies.org/Linux_2_6_23#head-102af265937262a7a21766ae58fddc1a29a5d8d7(
>> On-demand read-ahead on Linux 2.6.23)
>
> OK, I am looking for a way to make sure read requests on a SCSI drive
> actually hit the bus after a certain event. Is there a way to do this without
> tossing away the whole cache?
I'm not sure I understand what you're asking, but it sounds like you
want to do an O_DIRECT read. Open the file with O_DIRECT, then pass
a properly-aligned buffer to the read(2) call.
Cheers,
Jeff
prev parent reply other threads:[~2010-02-23 17:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-22 23:32 Oliver Neukum
[not found] ` <49b7c2351002221548ma5b8e81m80ac4b60a6eb9d9d@mail.gmail.com>
2010-02-22 23:59 ` Oliver Neukum
2010-02-23 17:38 ` Jeff Moyer [this message]
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