Re: [dpdk-dev] [PATCH] vhost: fix iotlb pool out-of-memory handling

[Jens Freimann <jfreimann@redhat.com>]

On Thu, Jan 25, 2018 at 04:06:53PM +0100, Maxime Coquelin wrote:
>In the unlikely case the IOTLB memory pool runs out of memory,
>an issue may happen if all entries are used by the IOTLB cache,
>and an IOTLB miss happen. If the iotlb pending list is empty,
>then no memory is freed and allocation fails a second time.
>
>This patch fixes this by doing an IOTLB cache random evict if
>the IOTLB pending list is empty, ensuring the second allocation
>try will succeed.
>
>In the same spirit, the opposite is done when inserting an
>IOTLB entry in the IOTLB cache fails due to out of memory. In
>this case, the IOTLB pending is flushed if the IOTLB cache is
>empty to ensure the new entry can be inserted.
>
>Fixes: d012d1f293f4 ("vhost: add IOTLB helper functions")
>Fixes: f72c2ad63aeb ("vhost: add pending IOTLB miss request list and helpers")
>
>Cc: stable@dpdk.org
>Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>---
> lib/librte_vhost/iotlb.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>

Reviewed-by: Jens Freimann <jfreimann@redhat.com>

regards,
Jens