linux-kernel - Re: mmap vs fs cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <513A8ECB.8000504@ubuntu.com>
Date:	Fri, 08 Mar 2013 20:22:19 -0500
From:	Phillip Susi <psusi@...ntu.com>
To:	Howard Chu <hyc@...as.com>
CC:	Chris Friesen <chris.friesen@...band.com>,
	"Kirill A. Shutemov" <kirill@...temov.name>,
	Johannes Weiner <hannes@...xchg.org>, Jan Kara <jack@...e.cz>,
	linux-kernel <linux-kernel@...r.kernel.org>, linux-mm@...ck.org
Subject: Re: mmap vs fs cache

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 03/08/2013 10:00 AM, Howard Chu wrote:
> Yes, that's what I was thinking. I added a 
> posix_madvise(..POSIX_MADV_RANDOM) but that had no effect on the
> test.

Yep, that's because it isn't implemented.

You might try MADV_WILLNEED to schedule it to be read in first.  I
believe that will only read in the requested page, without additional
readahead, and then when you fault on the page, it already has IO
scheduled, so the extra readahead will also be skipped.


-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with undefined - http://www.enigmail.net/

iQEcBAEBAgAGBQJROo7GAAoJEJrBOlT6nu759SAH+wRhoUIZUuzNGrhfUJ6RnwV8
VjFyftBCAsdC+Mzq81Da3KJOi+BdYV8VbkYNPzbKll5AnxzL5Udvbdyf9SkROhug
UgLWHe8pC6ZtHfSvWBCqS1YDLkzw+TiWwJzuL5iUEDC2NGuUJQ5SbhwyTEypvWai
pdPZeFVyhLAKOtAUwD5e/5vhBWSq2M1TG2C7BUCow2fbJ6kil+kWuXtiDeNPvtUk
4FwabL8zHA9pNtMlHB0cUrn5W3VQYGqeTaDngjyLxR1gw7uFQn52G47IPe2LAMGx
58L/tHjbkSY9oukGiMHoF1jiaFqJqV1pw+Q2P7S+0XsU8JdW6CmzotTqDmcozqE=
=DOZT
-----END PGP SIGNATURE-----
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/