Re: [PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cachewhen possible

From: Sasha Levin
Date: Tue Aug 28 2012 - 09:34:30 EST


On 08/28/2012 03:20 PM, Michael S. Tsirkin wrote:
> On Tue, Aug 28, 2012 at 03:04:03PM +0200, Sasha Levin wrote:
>> Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will
>> use indirect descriptors and allocate them using a simple
>> kmalloc().
>>
>> This patch adds a cache which will allow indirect buffers under
>> a configurable size to be allocated from that cache instead.
>>
>> Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
>
> I imagine this helps performance? Any numbers?

I ran benchmarks on the original RFC, I've re-tested it now and got similar
numbers to the original ones (virtio-net using vhost-net, thresh=16):

Before:
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec

87380 16384 16384 10.00 4512.12

After:
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec

87380 16384 16384 10.00 5399.18


Thanks,
Sasha
--
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/