Red Hat Bugzilla – Bug 152326
bio slab cache leak
Last modified: 2015-01-04 17:18:06 EST
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Description of problem:
The bio slab cache on RHEL 4 kernels seems to have a memory leak, or at least is
not freeing cached objects. After 4 days a machine that we use to process incoming mail has the following entry in /proc/slabinfo
biovec-1 2519354 2520804 16 226 1 : tunables 120 60 8 :\
slabdata 11154 11154 360
bio 2519338 2519696 96 41 1 : tunables 120 60 8 :\
slabdata 61456 61456 300
Another box that is running a UP kernel and is just sitting idle has the following enteries
biovec-1 34808 35030 16 226 1 : tunables 120 60 0 : \
slabdata 155 155 0
bio 34808 34906 128 31 1 : tunables 120 60 0 : \
slabdata 1126 1126 0
The first box has to be rebooted about every 5 days or it runs out of memory.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Boot RHEL 4 box with stock kernel
2. Let run for a couple days
Actual Results: Available memory constantly goes down.
Expected Results: Available memory shouldn't dissapear.
The box with 2.5 million active bio's is an SMP box the other is UP. They both use MD devices for all partitions.
This thread on LKML seems to talk about similar symptoms, though it is for 2.6.11-rc1.
theres a fix in testing for this problem in the in-progress U1 kernel.
http://people.redhat.com/davej/kernels/RHEL4 has current snapshots of this, but
be warned, these have not completed QA yet, and may offer additional problems.
How are things looking for the kernel for U1. Will this fix be in there or did
this fix come out with the recent security errata for EL4?
no, the security errata had security patches, and nothing else.
It should be fixed in the current U1 builds.