[dpdk-dev] [PATCH 2/3] vhost: fix long stall of vhost-user negotiation

[Maxime Coquelin]

On 01/22/2017 09:46 AM, Yuanhan Liu wrote:
> Setting up the mapping from GPA (guest physical address) to HPA (guest
> physical address) could be very time consuming when the guest memory is
> backened with small pages (4K). The bigger the guest memory, the longer
> it takes. This could lead a very long vhost-user negotiation.
>
> Since the mapping is only needed in zero copy mode so far, we could
> avoid such time consuming settup when zero copy is turned off (which is
> the default case).
>
> It's actually a workaround, a right fix might be to start a new thread,
> and hide the big latency there.
>
> Fixes: e246896178e6 ("vhost: get guest/host physical address mappings")
>
> Cc: stable at dpdk.org
> Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
> ---
>  lib/librte_vhost/vhost_user.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Thanks,
Maxime