Hi all,
I'm seeing memory leaks when running tests with valgrind memcheck tool [1]. It
seems like it's caused due to verbs_device refcount never reaching zero.
Last related commit is 8125fdeb69bb ("verbs: Avoid ibv_device memory leak"),
which seems like it should prevent this issue - but I'm not sure it covers all
cases.
When calling ibv_get_device_list, try_driver will eventually get called and set
the device refcount to one. The refcount for each device will be increased when
iterating the devices list, and on each verbs_init_context call.
In the free flow, the refcount is decreased on verbs_uninit_context and when
iterating the devices list - which brings the refcount back to one, as initially
set by try_driver (hence uninit_device isn't called).
Is there a reason for initializing refcount to one instead of zero? According to
the cited commit the reference count should be decreased when the device no
longer exists in the sysfs, but the device isn't necessarily removed from the sysfs.
[1]
==35758== HEAP SUMMARY:
==35758== in use at exit: 27,777 bytes in 88 blocks
==35758== total heap usage: 295 allocs, 207 frees, 141,751 bytes allocated
==35758==
==35758== 728 bytes in 1 blocks are possibly lost in loss record 3 of 8
==35758== at 0x4C2A935: calloc (vg_replace_malloc.c:711)
==35758== by 0x6FF263F: efa_device_alloc (efa.c:161)
==35758== by 0x4E42B67: try_driver (init.c:365)
==35758== by 0x4E42DBE: try_drivers (init.c:429)
==35758== by 0x4E42DBE: try_all_drivers (init.c:519)
==35758== by 0x4E43798: ibverbs_get_device_list (init.c:584)
==35758== by 0x4E40870: ibv_get_device_list@@IBVERBS_1.1 (device.c:74)
==35758== by 0x400691: main (device_list.c:46)
==35758==
==35758== 1,048 bytes in 1 blocks are possibly lost in loss record 6 of 8
==35758== at 0x4C2A935: calloc (vg_replace_malloc.c:711)
==35758== by 0x4E425C5: find_sysfs_devs_nl_cb (ibdev_nl.c:156)
==35758== by 0x5697E4B: nl_recvmsgs_report (in /usr/lib64/libnl-3.so.200.23.0)
==35758== by 0x56982B8: nl_recvmsgs (in /usr/lib64/libnl-3.so.200.23.0)
==35758== by 0x4E4734F: rdmanl_get_devices (rdma_nl.c:96)
==35758== by 0x4E42726: find_sysfs_devs_nl (ibdev_nl.c:205)
==35758== by 0x4E43501: ibverbs_get_device_list (init.c:538)
==35758== by 0x4E40870: ibv_get_device_list@@IBVERBS_1.1 (device.c:74)
==35758== by 0x400691: main (device_list.c:46)
Thanks,
Gal
