| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 15 Jan 2013 17:48:19 +0800
From: Wanlong Gao <gaowanlong@...fujitsu.com>
To: Paolo Bonzini <pbonzini@...hat.com>
CC: linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
hutao@...fujitsu.com, linux-scsi@...r.kernel.org,
virtualization@...ts.linux-foundation.org, mst@...hat.com,
rusty@...tcorp.com.au, asias@...hat.com, stefanha@...hat.com,
nab@...ux-iscsi.org
Subject: [PATCH 1/2] virtio-scsi: split out request queue set affinity function
These two patches are based on the multi-queue virtio-scsi patch set.
We set cpu affinity when the num_queues equals to the number
of VCPUs. Split out the set affinity function, this also
fix the bug when CPU IDs are not consecutive.
Signed-off-by: Wanlong Gao <gaowanlong@...fujitsu.com>
---
drivers/scsi/virtio_scsi.c | 50 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 44 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 3641d5f..16b0ef2 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -106,6 +106,9 @@ struct virtio_scsi {
u32 num_queues;
+ /* Does the affinity hint is set for virtqueues? */
+ bool affinity_hint_set;
+
struct virtio_scsi_vq ctrl_vq;
struct virtio_scsi_vq event_vq;
struct virtio_scsi_vq req_vqs[];
@@ -701,14 +704,45 @@ static struct scsi_host_template virtscsi_host_template_multi = {
&__val, sizeof(__val)); \
})
+static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
+{
+ int i;
+ int cpu;
+
+ /* In multiqueue mode, when the number of cpu is equal
+ * to the number of request queues, we let the qeueues
+ * to be private to one cpu by setting the affinity hint
+ * to eliminate the contention.
+ */
+ if ((vscsi->num_queues == 1 ||
+ vscsi->num_queues != num_online_cpus()) && affinity) {
+ if (vscsi->affinity_hint_set)
+ affinity = false;
+ else
+ return;
+ }
+
+ if (affinity) {
+ i = 0;
+ for_each_online_cpu(cpu) {
+ virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu);
+ i++;
+ }
+
+ vscsi->affinity_hint_set = true;
+ } else {
+ for (i = 0; i < vscsi->num_queues - VIRTIO_SCSI_VQ_BASE; i++)
+ virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1);
+
+ vscsi->affinity_hint_set = false;
+ }
+}
static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
- struct virtqueue *vq, bool affinity)
+ struct virtqueue *vq)
{
spin_lock_init(&virtscsi_vq->vq_lock);
virtscsi_vq->vq = vq;
- if (affinity)
- virtqueue_set_affinity(vq, vq->index - VIRTIO_SCSI_VQ_BASE);
}
static void virtscsi_init_tgt(struct virtio_scsi *vscsi, int i)
@@ -736,6 +770,8 @@ static void virtscsi_remove_vqs(struct virtio_device *vdev)
struct Scsi_Host *sh = virtio_scsi_host(vdev);
struct virtio_scsi *vscsi = shost_priv(sh);
+ virtscsi_set_affinity(vscsi, false);
+
/* Stop all the virtqueues. */
vdev->config->reset(vdev);
@@ -779,11 +815,13 @@ static int virtscsi_init(struct virtio_device *vdev,
if (err)
return err;
- virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0], false);
- virtscsi_init_vq(&vscsi->event_vq, vqs[1], false);
+ virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
+ virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
- vqs[i], vscsi->num_queues > 1);
+ vqs[i]);
+
+ virtscsi_set_affinity(vscsi, true);
virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
--
1.8.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists