lkml.org 
[lkml]   [2008]   [Jan]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH -v6 0/2] Fixing the issue with memory-mapped file times
Date
This is the sixth version of my solution for the bug #2645:

http://bugzilla.kernel.org/show_bug.cgi?id=2645

New since the previous version:

1) a few cosmetic changes according to the latest feedback
for the cleanup patch;

2) implementation of the following suggestion by Miklos Szeredi:

http://lkml.org/lkml/2008/1/17/158

These changes were tested as explained below. Please note that all
tests were performed with all recommended kernel debug options
enabled. Also note that the tests were performed on regular files
residing on both an ext3 partition and a tmpfs filesystem. I also
checked the block device case, which worked for me as well.

1. My own unit test:

http://bugzilla.kernel.org/attachment.cgi?id=14430

Result: all test cases passed successfully.

2. Unit test provided by Miklos Szeredi:

http://lkml.org/lkml/2008/1/14/104

Result: this test produced the following output:

debian-64:~# ./miklos_test test
begin 1200598736 1200598736 1200598617
write 1200598737 1200598737 1200598617
mmap 1200598737 1200598737 1200598738
b 1200598739 1200598739 1200598738
msync b 1200598739 1200598739 1200598738
c 1200598741 1200598741 1200598738
msync c 1200598741 1200598741 1200598738
d 1200598743 1200598743 1200598738
munmap 1200598743 1200598743 1200598738
close 1200598743 1200598743 1200598738
sync 1200598743 1200598743 1200598738
debian-64:~#

3. Regression tests were performed using the following test cases from
the LTP test suite:

msync01
msync02
msync03
msync04
msync05
mmapstress01
mmapstress09
mmapstress10

Result: no regressions were found while running these test cases.

4. Performance test was done using the program available from the
following link:

http://bugzilla.kernel.org/attachment.cgi?id=14493

Result: the impact of the changes was negligible for files of a few
hundred megabytes.

I wonder if these changes can be applied now.

These patches are the result of many fruitful discussions with
Miklos Szeredi, Peter Zijlstra, Rik van Riel, Peter Staubach,
and Jacob Oestergaard. I am grateful to you all for your support
during the days I was working on this long-standing nasty bug.


\
 
 \ /
  Last update: 2008-01-17 23:35    [W:1.662 / U:0.224 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site