Re: [PATCH 2/6] vhost_net: use vhost_add_used_and_signal_n() in vhost_zerocopy_signal_used()

From: Jason Wang
Date: Mon Aug 19 2013 - 22:33:18 EST


On 08/16/2013 05:54 PM, Michael S. Tsirkin wrote:
> On Fri, Aug 16, 2013 at 01:16:26PM +0800, Jason Wang wrote:
>> > Switch to use vhost_add_used_and_signal_n() to avoid multiple calls to
>> > vhost_add_used_and_signal(). With the patch we will call at most 2 times
>> > (consider done_idx warp around) compared to N times w/o this patch.
>> >
>> > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> So? Does this help performance then?
>

Looks like it can especially when guest does support event index. When
guest enable tx interrupt, this can saves us some unnecessary signal to
guest. I will do some test.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/