Red Hat Bugzilla – Bug 215939
kernel dm: use private biosets to avoid deadlock under memory pressure
Last modified: 2013-02-28 23:04:22 EST
+++ This bug was initially created as a clone of Bug #209851 +++
To avoid deadlock under memory pressure it is necessary for dm layers to use
private mempools and not share them.
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
Can you add some information about how common this problem is? Has it been seen
in the field? Typical workloads and configurations? Or strictly theoretical or
This problem can only happen in low memory situations when higher level (fs or
upper stacked dm device) succesfully allocate bios but lower level does not
because of low memory (upper levels drain common memory pool).
I saw this problem upstream but actually have no reports in RHEL4 but it use
There are no biosets in RHEL4 kernel so implementation will require backporting
of changes in block layer.
QE ack for RHEL4.5.
committed in stream U5 build 42.36. A test kernel with this patch is available
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 the 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.