From: Linus Torvalds <torvalds@osdl.org>
To: David Miller <davem@davemloft.net>
Cc: ranma@tdiedrich.de, gordonfarquharson@gmail.com, tbm@cyrius.com,
a.p.zijlstra@chello.nl, andrei.popa@i-neo.ro,
Andrew Morton <akpm@osdl.org>,
hugh@veritas.com, nickpiggin@yahoo.com.au, arjan@infradead.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: fix page_mkclean_one
Date: Wed, 27 Dec 2006 16:16:12 -0800 (PST) [thread overview]
Message-ID: <Pine.LNX.4.64.0612271601430.4473@woody.osdl.org> (raw)
In-Reply-To: <20061226.205518.63739038.davem@davemloft.net>
On Tue, 26 Dec 2006, David Miller wrote:
>
> I've seen it on sparc64, UP kernel, no preempt.
Ok, I still don't have a clue, but I think I at least have a new
test-case.
It can probably be improved upon, but this would _seem_ to trigger the
problem. Can people check?
You'd want to make sure you get page-put activity, by making TARGETSIZE be
big enough to cause memory pressure (and rather than making it bigger, you
might want to make your memory smaller instead, to make it run more
quickly. Either using "mem=128M" or big compiles or something...).
If it finds corruption, you'll see something like
Writing chunk 183858/183859 (99%)
Chunk ..
Chunk 120887 corrupted
Chunk 122372 corrupted
Chunk ...
Checking chunk 183858/183859 (99%)
otherwise it will just say
Writing chunk 183858/183859 (99%)
Checking chunk 183858/183859 (99%)
and exit.
I didn't spend a lot of time verifying this, but I _was_ able to cause
those "Chunk xxx corrupted" messages with this. There's probably a more
efficient better way to do it, but this is better than trying to use
rtorrent, and also makes any worries about what rtorrent does go away.
Of course, maybe it's this test-program that is buggy now, although it
looks trivial enough that I don't think it is.
I think my earlier stress-tester may not have triggered this, because it
just did all its writing in a linear order, so any LRU logic will happen
to write back old pages that we are no longer touching. The randomization
(and using a chunksize that isn't a multiple of a page-size) makes sure
that we're actually going to have lots of rewriting going on.
I think the test-case could probably be improved by having a munmap() and
page-cache flush in between the writing and the checking, to see whether
that shows the corruption easier (and possibly without having to start
paging in order to throw the pages out, which would simplify testing a
lot). But I haven't tested. I decided to post this asap, now that I've
recreated the corruption with something else, and something that is
possibly easier to analyze..
Linus
----
#include <sys/mman.h>
#include <sys/fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <time.h>
#define TARGETSIZE (256 << 20)
#define CHUNKSIZE (1460)
#define NRCHUNKS (TARGETSIZE / CHUNKSIZE)
#define SIZE (NRCHUNKS * CHUNKSIZE)
static void fillmem(void *start, int nr)
{
memset(start, nr, CHUNKSIZE);
}
static void checkmem(void *start, int nr)
{
unsigned char c = nr, *p = start;
int i;
for (i = 0; i < CHUNKSIZE; i++) {
if (*p++ != c) {
printf("Chunk %d corrupted \n", nr);
return;
}
}
}
int main(int argc, char **argv)
{
char *mapping;
int fd, i;
static int chunkorder[NRCHUNKS];
/*
* Make some random ordering of writing the chunks to the
* memory map..
*
* Start with fully ordered..
*/
for (i = 0; i < NRCHUNKS; i++)
chunkorder[i] = i;
/* ..and then mix it up randomly */
srandom(time(NULL));
for (i = 0; i < NRCHUNKS; i++) {
int index = (unsigned int) random() % NRCHUNKS;
int nr = chunkorder[index];
chunkorder[index] = chunkorder[i];
chunkorder[i] = nr;
}
fd = open("mapfile", O_RDWR | O_TRUNC | O_CREAT, 0666);
if (fd < 0)
return -1;
if (ftruncate(fd, SIZE) < 0)
return -1;
mapping = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (-1 == (int)(long)mapping)
return -1;
for (i = 0; i < NRCHUNKS; i++) {
int chunk = chunkorder[i];
printf("Writing chunk %d/%d (%d%%) \r", i, NRCHUNKS, 100*i/NRCHUNKS);
fillmem(mapping + chunk * CHUNKSIZE, chunk);
}
printf("\n");
for (i = 0; i < NRCHUNKS; i++) {
int chunk = i;
printf("Checking chunk %d/%d (%d%%) \r", i, NRCHUNKS, 100*i/NRCHUNKS);
checkmem(mapping + chunk * CHUNKSIZE, chunk);
}
printf("\n");
return 0;
}
next prev parent reply other threads:[~2006-12-28 0:16 UTC|newest]
Thread overview: 315+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-17 0:13 2.6.19 file content corruption on ext3 Andrei Popa
2006-12-17 12:06 ` Andrew Morton
2006-12-17 12:19 ` Marc Haber
2006-12-17 12:32 ` Andrei Popa
2006-12-17 13:39 ` Andrei Popa
2006-12-17 23:40 ` Andrew Morton
2006-12-18 1:02 ` Linus Torvalds
2006-12-18 1:22 ` Linus Torvalds
2006-12-18 1:29 ` Linus Torvalds
2006-12-18 1:57 ` Linus Torvalds
2006-12-18 4:51 ` Nick Piggin
2006-12-18 5:43 ` Andrew Morton
2006-12-18 7:22 ` Nick Piggin
2006-12-18 9:18 ` Andrew Morton
2006-12-18 9:26 ` Andrei Popa
2006-12-18 9:42 ` Nick Piggin
2006-12-19 8:51 ` Marc Haber
2006-12-19 9:28 ` Martin Michlmayr
2006-12-28 18:05 ` Marc Haber
2006-12-28 19:00 ` Linus Torvalds
2006-12-28 19:05 ` Petri Kaukasoina
2006-12-28 19:21 ` Linus Torvalds
2006-12-28 19:39 ` Dave Jones
2006-12-28 20:10 ` Arjan van de Ven
2006-12-29 9:23 ` maximilian attems
2006-12-29 15:02 ` Dave Jones
2006-12-29 18:52 ` maximilian attems
2006-12-29 19:14 ` Dave Jones
2006-12-28 21:24 ` Linus Torvalds
2006-12-28 21:36 ` Russell King
2006-12-28 22:37 ` Linus Torvalds
2006-12-28 22:50 ` David Miller
2006-12-28 23:01 ` Linus Torvalds
2006-12-29 1:38 ` Linus Torvalds
2006-12-29 1:59 ` Andrew Morton
2006-12-28 23:36 ` Anton Altaparmakov
2006-12-28 23:54 ` Linus Torvalds
2006-12-29 17:49 ` Guillaume Chazarain
2006-12-18 5:50 ` Linus Torvalds
2006-12-18 7:16 ` Andrew Morton
2006-12-18 7:17 ` Andrew Morton
2006-12-18 9:30 ` Nick Piggin
2006-12-18 7:30 ` Nick Piggin
2006-12-18 9:19 ` Andrei Popa
2006-12-18 9:38 ` Andrew Morton
2006-12-18 10:00 ` Andrei Popa
2006-12-18 10:11 ` Peter Zijlstra
2006-12-18 10:49 ` Andrei Popa
2006-12-18 15:24 ` Gene Heskett
2006-12-18 15:32 ` Peter Zijlstra
2006-12-18 15:47 ` Gene Heskett
2006-12-18 16:55 ` Peter Zijlstra
2006-12-18 18:03 ` Linus Torvalds
2006-12-18 18:24 ` Peter Zijlstra
2006-12-18 18:35 ` Linus Torvalds
2006-12-18 19:04 ` Andrei Popa
2006-12-18 19:10 ` Peter Zijlstra
2006-12-18 19:18 ` Linus Torvalds
2006-12-18 19:44 ` Andrei Popa
2006-12-18 20:14 ` Linus Torvalds
2006-12-18 20:41 ` Linus Torvalds
2006-12-18 21:11 ` Andrei Popa
2006-12-18 22:00 ` Alessandro Suardi
2006-12-18 22:45 ` Linus Torvalds
2006-12-19 0:13 ` Andrei Popa
2006-12-19 0:29 ` Linus Torvalds
2006-12-18 22:32 ` Linus Torvalds
2006-12-18 23:48 ` Andrei Popa
2006-12-19 0:04 ` Linus Torvalds
2006-12-19 0:29 ` Andrei Popa
2006-12-19 0:57 ` Linus Torvalds
2006-12-19 1:21 ` Andrew Morton
2006-12-19 1:44 ` Andrei Popa
2006-12-19 1:54 ` Andrew Morton
2006-12-19 2:04 ` Andrei Popa
2006-12-19 8:05 ` Andrei Popa
2006-12-19 8:24 ` Andrew Morton
2006-12-19 8:34 ` Pekka Enberg
2006-12-19 9:13 ` Marc Haber
2006-12-19 1:50 ` Andrei Popa
2006-12-19 1:03 ` Gene Heskett
2006-12-18 22:34 ` Gene Heskett
2006-12-22 17:27 ` Linus Torvalds
2006-12-18 21:43 ` Andrew Morton
2006-12-18 21:49 ` Peter Zijlstra
2006-12-19 23:42 ` Peter Zijlstra
2006-12-20 0:23 ` Linus Torvalds
2006-12-20 9:01 ` Peter Zijlstra
2006-12-20 9:12 ` Peter Zijlstra
2006-12-20 9:39 ` Arjan van de Ven
2006-12-20 11:26 ` [PATCH] mm: fix page_mkclean_one (was: 2.6.19 file content corruption on ext3) Peter Zijlstra
2006-12-20 11:39 ` Jesper Juhl
2006-12-20 11:42 ` Peter Zijlstra
2006-12-20 12:12 ` Jesper Juhl
2006-12-20 13:00 ` Hugh Dickins
2006-12-20 13:56 ` Peter Zijlstra
2006-12-20 17:03 ` Martin Michlmayr
2006-12-20 17:35 ` Linus Torvalds
2006-12-20 17:53 ` Martin Michlmayr
2006-12-20 19:01 ` Linus Torvalds
2006-12-20 19:50 ` Linus Torvalds
2006-12-20 20:22 ` Peter Zijlstra
2006-12-20 21:55 ` Dave Kleikamp
2006-12-20 22:25 ` Linus Torvalds
2006-12-20 22:59 ` Dave Kleikamp
2006-12-20 22:15 ` Peter Zijlstra
2006-12-20 22:20 ` Peter Zijlstra
2006-12-20 22:49 ` Linus Torvalds
2006-12-20 23:03 ` Peter Zijlstra
2006-12-21 9:16 ` Martin Schwidefsky
2006-12-21 9:20 ` Peter Zijlstra
2006-12-21 9:26 ` Martin Schwidefsky
2006-12-21 20:01 ` Linus Torvalds
2006-12-28 0:00 ` Martin Schwidefsky
2006-12-28 0:42 ` Linus Torvalds
2006-12-28 0:52 ` [PATCH] mm: fix page_mkclean_one David Miller
2006-12-21 2:36 ` [PATCH] mm: fix page_mkclean_one (was: 2.6.19 file content corruption on ext3) Trond Myklebust
2006-12-21 8:10 ` Peter Zijlstra
2006-12-20 23:24 ` David Chinner
2006-12-20 23:55 ` Linus Torvalds
2006-12-21 1:20 ` David Chinner
2006-12-20 23:32 ` Andrew Morton
2006-12-20 23:55 ` Linus Torvalds
2006-12-21 0:11 ` Andrew Morton
2006-12-21 0:22 ` Linus Torvalds
2006-12-21 0:24 ` Linus Torvalds
2006-12-21 15:48 ` Andrei Popa
2006-12-21 16:58 ` Linus Torvalds
2006-12-21 0:43 ` Linus Torvalds
2006-12-21 1:20 ` Andrew Morton
2006-12-21 2:54 ` Trond Myklebust
2006-12-21 17:19 ` Linus Torvalds
2006-12-21 7:32 ` Gordon Farquharson
2006-12-21 7:53 ` Linus Torvalds
2006-12-21 8:38 ` Martin Michlmayr
2006-12-21 8:59 ` Linus Torvalds
2006-12-21 9:17 ` Gordon Farquharson
2006-12-21 9:27 ` Andrew Morton
2006-12-22 4:20 ` Gordon Farquharson
2006-12-22 4:54 ` Linus Torvalds
2006-12-22 10:00 ` Martin Michlmayr
2006-12-22 10:06 ` Martin Michlmayr
2006-12-22 10:10 ` Martin Michlmayr
2006-12-22 11:07 ` Martin Michlmayr
2006-12-22 15:30 ` Gordon Farquharson
2006-12-22 17:11 ` Martin Michlmayr
2006-12-22 10:17 ` Andrew Morton
2006-12-22 11:12 ` Martin Michlmayr
2006-12-22 12:24 ` Andrei Popa
2006-12-22 12:32 ` Martin Michlmayr
2006-12-22 12:59 ` Martin Michlmayr
2006-12-22 13:25 ` Peter Zijlstra
2006-12-22 13:29 ` Peter Zijlstra
2006-12-22 17:56 ` Linus Torvalds
2006-12-22 19:20 ` Martin Michlmayr
2006-12-24 8:10 ` Gordon Farquharson
2006-12-24 8:43 ` Linus Torvalds
2006-12-24 8:57 ` Andrew Morton
2006-12-24 9:26 ` Linus Torvalds
2006-12-24 12:14 ` Andrei Popa
2006-12-24 12:26 ` Andrei Popa
2006-12-24 12:30 ` Andrew Morton
2006-12-24 12:31 ` Andrew Morton
2006-12-24 16:45 ` Andrei Popa
2006-12-24 17:16 ` Linus Torvalds
2006-12-24 18:07 ` Andrew Morton
2006-12-24 18:37 ` Linus Torvalds
2006-12-24 19:18 ` Linus Torvalds
2006-12-24 20:55 ` Gordon Farquharson
2006-12-26 10:31 ` Nick Piggin
2006-12-26 19:26 ` Linus Torvalds
2006-12-27 12:32 ` Jari Sundell
2006-12-27 12:44 ` valdyn
2006-12-27 13:33 ` Jari Sundell
2007-01-07 2:06 ` Tom Lanyon
2007-01-07 5:58 ` Tom Lanyon
2007-01-07 6:05 ` Andrew Morton
2006-12-24 21:21 ` Michael S. Tsirkin
2006-12-24 19:27 ` Gordon Farquharson
2006-12-24 19:35 ` Linus Torvalds
2006-12-24 20:10 ` Andrei Popa
2006-12-24 20:24 ` Linus Torvalds
2006-12-24 20:30 ` Andrei Popa
2006-12-26 17:51 ` Al Viro
2006-12-26 17:58 ` Al Viro
2006-12-24 22:01 ` Martin Michlmayr
2006-12-24 14:05 ` Martin Michlmayr
2006-12-26 16:17 ` Tobias Diedrich
2006-12-27 4:55 ` [PATCH] mm: fix page_mkclean_one David Miller
2006-12-27 7:00 ` Linus Torvalds
2006-12-27 8:39 ` Andrei Popa
2006-12-28 0:16 ` Linus Torvalds [this message]
2006-12-28 0:39 ` Linus Torvalds
2006-12-28 0:52 ` David Miller
2006-12-28 3:04 ` Linus Torvalds
2006-12-28 4:32 ` Gordon Farquharson
2006-12-28 4:53 ` Linus Torvalds
2006-12-28 5:20 ` Gordon Farquharson
2006-12-28 5:41 ` David Miller
2006-12-28 5:47 ` Gordon Farquharson
2006-12-28 10:13 ` Russell King
2006-12-28 14:15 ` Gordon Farquharson
2006-12-28 15:53 ` Martin Michlmayr
2006-12-28 17:27 ` Linus Torvalds
2006-12-28 18:44 ` Russell King
2006-12-28 19:01 ` Linus Torvalds
[not found] ` <97a0a9ac0612272115g4cce1f08n3c3c8498a6076bd5@mail.gmail.com>
[not found] ` <Pine.LNX.4.64.0612272120180.4473@woody.osdl.org>
2006-12-28 5:38 ` Gordon Farquharson
2006-12-28 9:30 ` Martin Michlmayr
2006-12-28 10:16 ` Martin Michlmayr
2006-12-28 10:49 ` Russell King
2006-12-28 14:56 ` Martin Michlmayr
2006-12-28 5:58 ` Gordon Farquharson
2006-12-28 17:08 ` Linus Torvalds
2006-12-28 5:55 ` Chen, Kenneth W
2006-12-28 6:10 ` Chen, Kenneth W
2006-12-28 6:27 ` David Miller
2006-12-28 17:10 ` Linus Torvalds
2006-12-28 9:15 ` Zhang, Yanmin
2006-12-28 17:15 ` Linus Torvalds
2006-12-28 11:50 ` Petri Kaukasoina
2006-12-28 15:09 ` Guillaume Chazarain
2006-12-28 19:19 ` Guillaume Chazarain
2006-12-28 19:28 ` Linus Torvalds
2006-12-28 19:45 ` Andrew Morton
2006-12-28 20:14 ` Linus Torvalds
2006-12-28 22:38 ` David Miller
2006-12-29 2:50 ` Segher Boessenkool
2006-12-29 6:48 ` Linus Torvalds
2006-12-29 8:58 ` Ok, explained.. (was Re: [PATCH] mm: fix page_mkclean_one) Linus Torvalds
2006-12-29 10:48 ` Linus Torvalds
2006-12-29 11:16 ` Andrei Popa
2006-12-29 12:09 ` Nick Piggin
2006-12-29 17:25 ` Linus Torvalds
2006-12-29 12:31 ` Ingo Molnar
2006-12-29 13:08 ` Martin Johansson
2006-12-29 14:08 ` Martin Michlmayr
2006-12-29 15:17 ` Stephen Clark
2006-12-29 15:54 ` Martin Michlmayr
2006-12-29 22:16 ` Andrew Morton
2006-12-29 22:24 ` Andrew Morton
2006-12-29 22:42 ` Linus Torvalds
2006-12-29 23:32 ` Theodore Tso
2006-12-29 23:59 ` Linus Torvalds
2006-12-30 0:05 ` Andrew Morton
2006-12-30 0:50 ` Linus Torvalds
2006-12-29 23:51 ` Andrew Morton
2006-12-30 0:11 ` Linus Torvalds
2006-12-30 0:33 ` Andrew Morton
2006-12-30 0:58 ` Linus Torvalds
2006-12-30 1:16 ` Andrew Morton
2006-12-29 15:27 ` Theodore Tso
2006-12-29 17:51 ` Linus Torvalds
2006-12-29 12:19 ` [patch] fix data corruption bug in __block_write_full_page() Ingo Molnar
2007-01-02 11:20 ` Christoph Hellwig
2007-01-02 12:06 ` Ingo Molnar
2007-01-02 12:16 ` Christoph Hellwig
2006-12-28 22:35 ` [PATCH] mm: fix page_mkclean_one Mike Galbraith
2006-12-22 15:01 ` [PATCH] mm: fix page_mkclean_one (was: 2.6.19 file content corruption on ext3) Patrick Mau
2006-12-23 8:15 ` Andrei Popa
2006-12-22 15:08 ` Gordon Farquharson
2006-12-22 10:01 ` Martin Michlmayr
2006-12-22 15:16 ` Gordon Farquharson
2006-12-21 12:30 ` Russell King
2006-12-21 12:36 ` Russell King
2006-12-21 11:21 ` Martin Michlmayr
2006-12-20 22:11 ` Russell King
2006-12-21 8:18 ` Martin Michlmayr
2006-12-21 9:54 ` Russell King
2006-12-20 14:55 ` Martin Schwidefsky
2006-12-20 14:27 ` 2.6.19 file content corruption on ext3 Martin Schwidefsky
2006-12-20 9:32 ` Peter Zijlstra
2006-12-20 14:15 ` Andrei Popa
2006-12-20 14:23 ` Peter Zijlstra
2006-12-20 16:30 ` Andrei Popa
2006-12-20 16:36 ` Peter Zijlstra
2006-12-19 7:38 ` Peter Zijlstra
2006-12-19 4:36 ` Nick Piggin
2006-12-19 6:34 ` Linus Torvalds
2006-12-19 6:51 ` Nick Piggin
2006-12-19 7:26 ` Linus Torvalds
2006-12-19 8:04 ` Linus Torvalds
2006-12-19 9:00 ` Peter Zijlstra
2006-12-19 9:05 ` Peter Zijlstra
[not found] ` <4587B762.2030603@yahoo.com.au>
2006-12-19 10:32 ` Andrew Morton
2006-12-19 10:42 ` Nick Piggin
2006-12-19 10:47 ` Andrew Morton
2006-12-19 10:52 ` Peter Zijlstra
2006-12-19 10:58 ` Nick Piggin
2006-12-19 11:51 ` Peter Zijlstra
2006-12-19 10:55 ` Nick Piggin
2006-12-19 16:51 ` Linus Torvalds
2006-12-19 17:43 ` Linus Torvalds
2006-12-19 18:59 ` Linus Torvalds
2006-12-19 21:30 ` Peter Zijlstra
2006-12-19 22:51 ` Linus Torvalds
2006-12-19 22:58 ` Andrew Morton
2006-12-19 23:06 ` Peter Zijlstra
2006-12-19 23:07 ` Peter Zijlstra
2006-12-20 0:03 ` Linus Torvalds
2006-12-20 0:18 ` Andrew Morton
2006-12-20 18:02 ` Stephen Clark
2006-12-20 5:56 ` Jari Sundell
2006-12-19 21:56 ` Florian Weimer
2006-12-21 13:03 ` Peter Zijlstra
2006-12-21 20:40 ` Andrew Morton
2006-12-19 20:03 ` dean gaudet
2006-12-19 7:22 ` Peter Zijlstra
2006-12-19 7:59 ` Nick Piggin
2006-12-19 8:14 ` Linus Torvalds
2006-12-19 9:40 ` Nick Piggin
2006-12-19 16:46 ` Linus Torvalds
2006-12-28 15:50 [PATCH] mm: fix page_mkclean_one martin
2007-02-01 22:40 Mark Groves
2007-02-02 8:42 ` Nick Piggin
2007-02-02 13:08 ` Evgeniy Polyakov
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