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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I know this fixes RHEL3 (2.4 kernels) and
the RHEL4 U6/U7 (2.6.9 kernels), but testing this with RHEL5 U2 (2.6.18-92.el5PAE)
shows that the memory is still being swapped out which would result in client
data corruption.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
pvfs2-developers-bounces@beowulf-underground.org
[mailto:pvfs2-developers-bounces@beowulf-underground.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Bart Taylor<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, November 20, 2008
4:32 PM<br>
<b><span style='font-weight:bold'>To:</span></b>
pvfs2-developers@beowulf-underground.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [Pvfs2-developers] Re:
patch for client data corruption with 2.4kernels</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>I neglected the header
file; attached is an additional patch to catch it. Both of these patches should
apply cleanly to head.<br>
<br>
Bart.<br>
<br>
<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Thu, Nov 20, 2008 at 1:54 PM, Bart Taylor <<a
href="mailto:batayl@gmail.com">batayl@gmail.com</a>> wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Hey guys,<br>
<br>
This patch fixes a client data corruption issue on Linux 2.4 systems. We worked
with Phil off-list and determined that the kernel's mapped buffers are not
staying pinned in memory as they should be. We were able to verify that under
heavy swapping the pvfs2-client-core memory was being moved, invalidating the
pointers. This fix uses mlock to hold the two buffers in place, and we were
able to verify that it fixes the swapping issue. There are compile time flags
to ensure it is only added for Linux 2.4 systems.<br>
<font color="#888888"><span style='color:#888888'><br>
Bart.</span></font><o:p></o:p></span></font></p>
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