From: Russell King <rmk@arm.linux.org.uk>
To: James Bottomley <James.Bottomley@steeleye.com>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>,
linux-arch@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
davej@codemonkey.org.uk
Subject: Re: [CFT] read+shared mmap write+read data corruption
Date: Mon, 28 May 2007 11:05:13 +0100 [thread overview]
Message-ID: <20070528100513.GC26046@flint.arm.linux.org.uk> (raw)
In-Reply-To: <1180310431.3711.27.camel@mulgrave.il.steeleye.com>
On Sun, May 27, 2007 at 07:00:31PM -0500, James Bottomley wrote:
> Ok, output on parisc is:
>
> jejb@ioz:~$ ./a.out
> firstfirstfirst
> firstfirstfirst
> secondsecondsec
>
> Which is correct. It remains correct even if I drop the msync().
With Lennert's new program, I get mostly:
firstfirstfirst
firstfirstfirst
firstfirstfirst
but occasionally:
firstfirstfirst
firstfirstfirst
secondsecondsec
However, if I open code the memcpy() in the MAPREAD to copy one word
at a time, then I reliably get the "secondsecondsec" line. But if I
convert the memcpy() in MAPWRITE in the same way, I'm back to mostly
getting the failure with the occasional success. Utterly confused.
Unless someone's got a theory, I'm stumped.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
next prev parent reply other threads:[~2007-05-28 10:05 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-27 10:49 [CFT] read+shared mmap write+read data corruption Russell King
2007-05-27 14:16 ` James Bottomley
2007-05-27 22:25 ` Lennert Buytenhek
2007-05-27 23:06 ` David Miller
2007-05-27 23:05 ` David Miller
2007-05-28 0:31 ` James Bottomley
2007-05-28 12:44 ` Lennert Buytenhek
2007-05-29 5:35 ` David Miller
2007-05-29 9:12 ` Russell King
2007-05-29 10:26 ` David Miller
2007-05-27 22:24 ` Lennert Buytenhek
2007-05-28 0:00 ` James Bottomley
2007-05-28 10:05 ` Russell King [this message]
2007-05-28 14:17 ` James Bottomley
2007-05-28 14:39 ` Lennert Buytenhek
2007-05-29 3:06 ` James Bottomley
2007-05-29 3:15 ` Lennert Buytenhek
2007-05-29 14:32 ` James Bottomley
2007-05-29 17:13 ` Russell King
2007-05-29 5:58 ` David Miller
2007-05-28 15:04 ` Russell King
2007-05-29 15:42 ` Lennert Buytenhek
2007-05-28 12:33 ` Lennert Buytenhek
2007-05-28 14:22 ` James Bottomley
2007-05-28 12:38 ` Lennert Buytenhek
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