Re: [PATCH v3 0/4] net/virtio: fix memory leak when reinitializing device

[Yuanhan Liu <yliu@fridaylinux.org>]

On Tue, Jan 23, 2018 at 04:54:39PM +0100, Olivier Matz wrote:
> When devops->configure() is called, the queues may be reallocated
> if the features flag changed, but the previous are not freed. This
> patchset fixes this issue.

Seires applied to dpdk-next-virtio.

Thanks.

	--yliu
> 
> To really point out the issue, I instrumented rte_malloc,
> rte_memzone_reserve, rte_mbuf_alloc to track the allocations and frees.
> For reference, the patch is available here:
> https://www.droids-corp.org/~zer0/hidden/0001-debug-malloc.patch
> Iit conflicts a bit with the patchset, but it is quite easy to solve.
> 
> To reproduce the issue:
> 
>   cd dpdk
>   make config T=x86_64-native-linuxapp-gcc
>   sed -i 's,CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_INIT=n,CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_INIT=y,' build/.config
>   make -j4
>   mkdir -p /mnt/huge
>   mount -t hugetlbfs nodev /mnt/huge
>   echo 256 > /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
>   modprobe uio_pci_generic
>   python usertools/dpdk-devbind.py -b uio_pci_generic 0000:00:02.0
>   ./build/app/testpmd -l 0,1 --log-level 8 -- --total-num-mbufs=16384 \
>      -i --port-topology=chained --disable-hw-vlan-filter \
>      --disable-hw-vlan-strip --enable-rx-cksum --enable-lro \
>      --txqflags=0 --no-lsc-interrupt
> 
>   # testpmd commands
>   port stop 0
>   port config all rx-cksum off
>   port start 0
>   quit
> 
> Without the patchset, the debug patch displays a leak of mbufs allocated
> from virtio_dev_rx_queue_setup_finish() and a leak of rte_mallocs allocated
> from virtio_init_queue().
> 
> After the patchset, only one malloc is remaining after the device close,
> but this is normal, because this area is freed in dev_uninit().
> 
> v2 -> v3:
> - fix queue flushing with vector Rx enabled (Tiwei).
>   The patch is slightly changed compared to what was proposed by mail,
>   due to a checkpatch warning.
> 
> v1 -> v2:
> - move the vq != NULL check from the refactor patch to the memory
>   leak fix patch (Yuanhan)
> - new patch to fix queue flushing with vector Rx enabled (Tiwei)
> - move the backportable fixes at the beginning of the patchset (Yuanhan)
> - remove Cc stable on the typo fix (Yuanhan)
>   note: I finally kept it in the patchset
> 
> 
> Olivier Matz (4):
>   net/virtio: fix queue flushing with vector Rx enabled
>   net/virtio: fix memory leak when reinitializing device
>   net/virtio: rationalize queue flushing
>   net/virtio: fix typo in function name
> 
>  drivers/net/virtio/virtio_ethdev.c | 71 +++++++++++++++++---------------------
>  drivers/net/virtio/virtqueue.c     | 30 +++++++++++++---
>  drivers/net/virtio/virtqueue.h     | 13 ++++++-
>  3 files changed, 69 insertions(+), 45 deletions(-)
> 
> -- 
> 2.11.0