Saul Tamari wrote:
This patch reduces the size of memory being cleared on every virtio-blk IO. Improve number of IOPS when using avirtio-blk device. On every virtio-blk IO command passed to QEMU, virtio_blk_alloc_request() allocates and clears (with qemu_mallocz()) a VirtIOBlockReq object. The sizeof(VirtIOBlockReq) equals 41040 bytes on my x86-64 machine. By moving the 'elem' variable to the end of VirtIOBlockReq and clearing only upto the address of the 'elem.in_addr' field, the memset() call now clears only 80 bytes. Signed-off-by: Saul Tamari <stamari@xxxxxxxxx> --- diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 2630b99..de74b00 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -79,12 +79,13 @@ static inline void virtio_identify_template(struct virtio_blk_config *bc)
This patch is whitespace damaged by your mailer. Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
