Re: [PATCH v2 1/2] virtio-ring: Use threshold for switching to indirect descriptors

2012-08-28 Thread Michael S. Tsirkin
On Tue, Aug 28, 2012 at 03:04:02PM +0200, Sasha Levin wrote: > Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect > descriptors even if we have plenty of space in the ring. This means that > we take a performance hit at all times due to the overhead of creating > indirect desc

[PATCH v2 1/2] virtio-ring: Use threshold for switching to indirect descriptors

2012-08-28 Thread Sasha Levin
Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect descriptors even if we have plenty of space in the ring. This means that we take a performance hit at all times due to the overhead of creating indirect descriptors. Instead, use it only after we're below a configurable offse