+++ This bug was initially created as a clone of Bug #456686 +++ Description of problem: There is a missing memory barrier in the current aio_complete in the RHEL4 kernels causing a race between read_events/aio_complete causing the thread in read_events to sleep indefinitely, hanging the application that is waiting on I/O completion. This was reported upstream by Quentin Barnes of Yahoo: http://lkml.org/lkml/2008/3/12/207 Fix has been merged in 2.6.26: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6cb2a21049b8990df4576c5fce4d48d0206c22d5 And was also accepted for 2.6.24.y: http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.24.y.git;a=commit;h=0db49fc729eee503836ea12745b55f7f802d2abb Version-Release number of selected component (if applicable): How reproducible: Unclear. Depends on the AIO application; Quentin reports seeing hangs virtually 100% of the time. Looking for a straightforward reproducer for this now and will update with details when they are available. Steps to Reproduce: < to be filled > Actual results: Application hangs in read_events Expected results: No hang. AIO completes as normal. Additional info: --- Additional comment from pm-rhel on 2008-09-03 09:12:05 EDT --- Updating PM score. --- Additional comment from pm-rhel on 2008-09-22 13:53:39 EDT --- 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.
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.
*** Bug 456687 has been marked as a duplicate of this bug. ***
Updating PM score.
in kernel-2.6.18-141.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5 Please do NOT transition this bugzilla state to VERIFIED until our QE team has sent specific instructions indicating when to do so. However feel free to provide a comment indicating that this fix has been verified.
~~ Attention - RHEL 5.4 Beta Released! ~~ RHEL 5.4 Beta has been released! There should be a fix present in the Beta release that addresses this particular request. Please test and report back results here, at your earliest convenience. RHEL 5.4 General Availability release is just around the corner! If you encounter any issues while testing Beta, please describe the issues you have encountered and set the bug into NEED_INFO. If you encounter new issues, please clone this bug to open a new issue and request it be reviewed for inclusion in RHEL 5.4 or a later update, if it is not of urgent severity. Please do not flip the bug status to VERIFIED. Only post your verification results, and if available, update Verified field with the appropriate value. Questions can be posted to this bug or your customer or partner representative.
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-2009-1243.html