Red Hat Bugzilla – Bug 641315
Backport upstream cacheing fix for optimizing reads from /proc/vmcore
Last modified: 2011-05-19 08:49:20 EDT
Description of problem: The mechanism used to read /proc/vmcore on 6.0 is not optimal because it does not always take advantage of reading through cached memory. The following upstream commit should be backported because it dramatically improves performance for at least one partner that tested on RHEL6.0: http://lists.infradead.org/pipermail/kexec/2010-September/004498.html Jon.
*** Bug 641990 has been marked as a duplicate of this bug. ***
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=2821989 test build
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
Patch(es) available on kernel-2.6.32-89.el6
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Reading the /proc/vmcore file on a Red Hat Enterprise Linux 6 system was not optimal because it did not always take advantage of reading through the cached memory. With this update, access to the /dev/oldmem device in the /proc/vmcore file is cached, resulting in faster copying to user space.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0542.html