On Thu, Feb 13, 2020 at 05:59:27PM +0300, Denis Plotnikov wrote: > v1: > * seg_max default value changing removed > > --- > The goal is to reduce the amount of requests issued by a guest on > 1M reads/writes. This rises the performance up to 4% on that kind of > disk access pattern. > > The maximum chunk size to be used for the guest disk accessing is > limited with seg_max parameter, which represents the max amount of > pices in the scatter-geather list in one guest disk request. > > Since seg_max is virqueue_size dependent, increasing the virtqueue > size increases seg_max, which, in turn, increases the maximum size > of data to be read/write from a guest disk. > > More details in the original problem statment: > https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg03721.html > > Suggested-by: Denis V. Lunev > Signed-off-by: Denis Plotnikov > --- > hw/block/virtio-blk.c | 2 +- > hw/core/machine.c | 2 ++ > hw/scsi/virtio-scsi.c | 2 +- > 3 files changed, 4 insertions(+), 2 deletions(-) I fixed up the "virtuqueue" typo in the commit message and the mis-formatted commit description (git-am(1) stops including lines after the first "---"). Thanks, applied to my block tree: https://github.com/stefanha/qemu/commits/block Stefan