[libvirt] Found mem leak in libvirtd, need help to debug

[Piotr Rybicki]

Hi guys.

W dniu 2015-11-20 o 11:29, Piotr Rybicki pisze:
>
>> I've seen some of theese already. The bug is actually not in libvirt but
>> in gluster's libgfapi library, so any change in libvirt won't help.
>>
>> This was tracked in gluster as:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=1093594
>>
>> I suggest you update the gluster library to resolve this issue.
>>

I've tested further this issue.

I have to report, that mem leak still exists in latest versions
gluster: 3.7.6
libvirt 1.3.1

mem leak exists even when starting domain (virsh start DOMAIN) which 
acesses drivie via libgfapi (although leak is much smaller than with 
gluster 3.5.X).

when using drive via file (gluster fuse mount), there is no mem leak 
when starting domain.

my drive definition (libgfapi):

     <disk type='network' device='disk'>
       <driver name='qemu' type='raw' cache='writethrough' iothread='1'/>
       <source protocol='gluster' name='pool/disk-sys.img'>
         <host name='X.X.X.X' transport='rdma'/>
       </source>
       <blockio logical_block_size='512' physical_block_size='32768'/>
       <target dev='vda' bus='virtio'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' 
function='0x0'/>
     </disk>


valgrind details (libgfapi):

# valgrind --leak-check=full --show-reachable=yes 
--child-silent-after-fork=yes libvirtd --listen 2> libvirt-gfapi.log

==6532== Memcheck, a memory error detector
==6532== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==6532== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==6532== Command: libvirtd --listen
==6532==
==6532== Warning: noted but unhandled ioctl 0x89a2 with no 
size/direction hints.
==6532==    This could cause spurious value errors to appear.
==6532==    See README_MISSING_SYSCALL_OR_IOCTL for guidance on writing 
a proper wrapper.
2016-02-09 12:20:26.732+0000: 6535: info : libvirt version: 1.3.1
2016-02-09 12:20:26.732+0000: 6535: info : hostname: adm-office
2016-02-09 12:20:26.732+0000: 6535: warning : qemuDomainObjTaint:2223 : 
Domain id=1 name='gentoo-intel' 
uuid=f9fd934b-cbda-af4e-cc98-0dd2c8dd6c2c is tainted: host-cpu
2016-02-09 12:21:29.924+0000: 6532: error : qemuMonitorIO:689 : internal 
error: End of file from monitor
==6532==
==6532== HEAP SUMMARY:
==6532==     in use at exit: 3,726,573 bytes in 15,324 blocks
==6532==   total heap usage: 238,573 allocs, 223,249 frees, 
1,020,776,752 bytes allocated

(...)

==6532== LEAK SUMMARY:
==6532==    definitely lost: 19,760 bytes in 97 blocks
==6532==    indirectly lost: 21,098 bytes in 122 blocks
==6532==      possibly lost: 2,698,764 bytes in 67 blocks
==6532==    still reachable: 986,951 bytes in 15,038 blocks
==6532==         suppressed: 0 bytes in 0 blocks
==6532==
==6532== For counts of detected and suppressed errors, rerun with: -v
==6532== ERROR SUMMARY: 96 errors from 96 contexts (suppressed: 0 from 0)

full log:
http://195.191.233.1/libvirt-gfapi.log
http://195.191.233.1/libvirt-gfapi.log.bz2

Best regards
Piotr Rybicki