Hi Michael,
On 3/30/24 19:02, Gavin Shan wrote:
On 3/28/24 19:31, Michael S. Tsirkin wrote:
On Thu, Mar 28, 2024 at 10:21:49AM +1000, Gavin Shan wrote:
All the callers of vhost_get_avail_idx() are concerned to the memory
barrier, imposed by smp_rmb() to ensure the order of the available
ring entry read and avail_idx read.
Improve vhost_get_avail_idx() so that smp_rmb() is executed when
the avail_idx is advanced. With it, the callers needn't to worry
about the memory barrier.
Suggested-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
Previous patches are ok. This one I feel needs more work -
first more code such as sanity checking should go into
this function, second there's actually a difference
between comparing to last_avail_idx and just comparing
to the previous value of avail_idx.
I will pick patches 1-2 and post a cleanup on top so you can
take a look, ok?
Thanks, Michael. It's fine to me.
A kindly ping.
If it's ok to you, could you please merge PATCH[1-2]? Our downstream
9.4 need the fixes, especially for NVidia's grace-hopper and grace-grace
platforms.
For PATCH[3], I also can help with the improvement if you don't have time
for it. Please let me know.
Thanks,
Gavin
