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
This was reported upstream by Quentin Barnes of Yahoo:
Fix has been merged in 2.6.26:
And was also accepted for 2.6.24.y:
Version-Release number of selected component (if applicable):
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 >
Application hangs in read_events
No hang. AIO completes as normal.
Updating PM score.
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
Patch posted for review:
Committed in 78.29.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/
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.