From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: 2.5.33-mm4 filemap_copy_from_user: Unexpected page fault From: Steven Cole In-Reply-To: <3D78DD07.E36AE3A9@zip.com.au> References: <1031327285.1984.155.camel@spc9.esa.lanl.gov> <3D78DD07.E36AE3A9@zip.com.au> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: 06 Sep 2002 11:03:23 -0600 Message-Id: <1031331803.2799.178.camel@spc9.esa.lanl.gov> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-mm@kvack.org List-ID: On Fri, 2002-09-06 at 10:51, Andrew Morton wrote: > Steven Cole wrote: > > > > With 2.5.33-mm4, I tried running dbench on an ext2 partition and was > > able to run up to dbench 80 successfully. However, at dbench 96, I got > > four messages like this: > > > > filemap_copy_from_user: Unexpected page fault > > Yep. This means that the page we faulted in by-hand in generic_file_write() > wasn't resident during the subsequent copy_from_user(). > > That fault-in by-hand is there to prevent a deadlock. That printk > meand that it isnt working all the time. We have (always had) a > problem. > > > Shortly after this, the box hung again, > > ... > > >>EIP; c0159bf4 <===== > > Trace; c0159e1e > > Trace; c013b8aa > > Trace; c013b4cb <__pdflush+12b/1d0> > > Hum. Thanks for that. > > I've been dbenching and compiling all night. And yet, it > seems that the dirty inode search in sync_sb_inodes() can trivially > lock up. > > Does this fix? > > fs-writeback.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) [patch snipped] Unfortunately no. With that patch, it got up to dbench 10 on ext3 and then it hung again. I haven't reboot the box yet in case the output from sysrq-p would be useful. It is a pain to type in though. I had vmstat -n 1 1200 running in another terminal and here are the last several lines of that output before the freeze: 0 0 0 0 636688 25356 19192 0 0 0 0 1077 2983 19 44 37 10 0 0 0 589504 25856 65452 0 0 24 0 1022 41 2 37 61 0 10 4 0 531940 26644 122060 0 0 12 22684 1194 431 6 51 42 0 10 3 0 527316 26736 126592 0 0 4 12944 1189 246 2 7 91 0 10 3 0 487488 27372 165676 0 0 12 15652 1238 569 7 41 52 0 10 1 0 487476 27372 165676 0 0 0 4868 1167 84 0 3 97 3 7 0 0 466636 27692 185728 0 0 20 12340 1188 202 6 24 70 0 10 2 0 462580 27772 189280 0 0 20 13240 1302 282 1 7 91 0 10 3 0 457832 27848 191244 0 0 8 9680 1350 334 2 5 93 0 10 3 0 457448 27864 191564 0 0 4 10064 1406 277 0 2 99 0 10 3 0 450812 27940 197804 0 0 12 12552 1382 351 2 6 92 4 6 3 0 442804 28132 205204 0 0 12 21928 1231 721 7 17 75 0 10 3 0 441248 28432 206376 0 0 12 18552 1195 5658 17 34 49 0 10 2 0 440500 28468 206712 0 0 4 2288 1153 394 1 3 96 9 3 5 0 438728 28580 207632 0 0 24 15100 1293 319 4 13 83 Steven -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/