From fc4324b4597c4eb8907207e82f9a6acec84dd335 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 19 Mar 2014 17:08:24 +1030 Subject: [PATCH] virtio-blk: base queue-depth on virtqueue ringsize or module param Venkatash spake thus: virtio-blk set the default queue depth to 64 requests, which was insufficient for high-IOPS devices. Instead set the blk-queue depth to the device's virtqueue depth divided by two (each I/O requires at least two VQ entries). But behold, Ted added a module parameter: Also allow the queue depth to be something which can be set at module load time or via a kernel boot-time parameter, for testing/benchmarking purposes. And I rewrote it substantially, mainly to take VIRTIO_RING_F_INDIRECT_DESC into account. As QEMU sets the vq size for PCI to 128, Venkatash's patch wouldn't have made a change. This version does (since QEMU also offers VIRTIO_RING_F_INDIRECT_DESC. Inspired-by: "Theodore Ts'o" Based-on-the-true-story-of: Venkatesh Srinivas Cc: "Michael S. Tsirkin" Cc: virtio-dev@lists.oasis-open.org Cc: virtualization@lists.linux-foundation.org Cc: Frank Swiderski Signed-off-by: Rusty Russell --- Reading git-format-patch failed