* [Qemu-devel] [RFC][PATCH v2] suppressing queue notification with queue depth parameter (was: [RFC][PATCH] Queue notify support for virtio block device.)
@ 2010-01-14 10:33 Vadim Rozenfeld
2010-01-14 14:30 ` Anthony Liguori
0 siblings, 1 reply; 2+ messages in thread
From: Vadim Rozenfeld @ 2010-01-14 10:33 UTC (permalink / raw)
To: qemu-devel; +Cc: Dor Laor, Avi Kivity
The following patch allows to suppress virtio queue notification with
the number of requests passed as parameter.
Changes from v1:
- code styling,
- parameter "x-queue-depth-suppress-notify" for queue depth adjustment.
repository: /home/vadimr/work/upstream/qemu
branch: master
commit d23a1c2fbd23e3da9a671a35c95324d2c630e4c9
Author: Vadim Rozenfeld <vrozenfe@redhat.com>
Date: Thu Jan 14 08:09:26 2010 +0200
[RFC][PATCH v2] suppressing queue notification with queue depth
parameter
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index cb1ae1f..93b584d 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -28,6 +28,8 @@ typedef struct VirtIOBlock
char serial_str[BLOCK_SERIAL_STRLEN + 1];
QEMUBH *bh;
size_t config_size;
+ unsigned int queue_depth;
+ unsigned int requests;
} VirtIOBlock;
static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
@@ -87,6 +89,8 @@ typedef struct VirtIOBlockReq
struct VirtIOBlockReq *next;
} VirtIOBlockReq;
+static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue
*vq);
+
static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
{
VirtIOBlock *s = req->dev;
@@ -95,6 +99,11 @@ static void virtio_blk_req_complete(VirtIOBlockReq
*req, int status)
virtqueue_push(s->vq, &req->elem, req->qiov.size +
sizeof(*req->in));
virtio_notify(&s->vdev, s->vq);
+ virtio_blk_handle_output(&s->vdev, s->vq);
+ if (--s->requests == (s->queue_depth - 1)) {
+ virtio_queue_set_notification(s->vq, 1);
+ }
+
qemu_free(req);
}
@@ -340,6 +349,10 @@ static void virtio_blk_handle_output(VirtIODevice
*vdev, VirtQueue *vq)
exit(1);
}
+ if (++s->requests == s->queue_depth) {
+ virtio_queue_set_notification(s->vq, 0);
+ }
+
req->out = (void *)req->elem.out_sg[0].iov_base;
req->in = (void *)req->elem.in_sg[req->elem.in_num -
1].iov_base;
@@ -502,6 +515,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev,
DriveInfo *dinfo)
s->vdev.reset = virtio_blk_reset;
s->bs = dinfo->bdrv;
s->rq = NULL;
+ s->queue_depth = drive_get_queue_depth(dinfo->bdrv);
if (strlen(ps))
strncpy(s->serial_str, ps, sizeof(s->serial_str));
else
diff --git a/qemu-config.c b/qemu-config.c
index c3203c8..6fcf958 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -78,6 +78,10 @@ QemuOptsList qemu_drive_opts = {
},{
.name = "readonly",
.type = QEMU_OPT_BOOL,
+ },{
+ .name = "x-queue-depth-suppress-notify",
+ .type = QEMU_OPT_NUMBER,
+ .help = "number of requests in queueu before suppressing
notify",
},
{ /* end if list */ }
},
diff --git a/sysemu.h b/sysemu.h
index 9d80bb2..6eecbe1 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -183,6 +183,7 @@ typedef struct DriveInfo {
BlockInterfaceErrorAction on_read_error;
BlockInterfaceErrorAction on_write_error;
char serial[BLOCK_SERIAL_STRLEN + 1];
+ int queue_depth;
QTAILQ_ENTRY(DriveInfo) next;
} DriveInfo;
@@ -198,6 +199,7 @@ extern DriveInfo *drive_get_by_id(const char *id);
extern int drive_get_max_bus(BlockInterfaceType type);
extern void drive_uninit(DriveInfo *dinfo);
extern const char *drive_get_serial(BlockDriverState *bdrv);
+extern int drive_get_queue_depth(BlockDriverState *bdrv);
extern BlockInterfaceErrorAction drive_get_on_error(
BlockDriverState *bdrv, int is_read);
diff --git a/vl.c b/vl.c
index b048e89..517d290 100644
--- a/vl.c
+++ b/vl.c
@@ -2043,6 +2043,18 @@ const char *drive_get_serial(BlockDriverState
*bdrv)
return "\0";
}
+int drive_get_queue_depth(BlockDriverState *bdrv)
+{
+ DriveInfo *dinfo;
+
+ QTAILQ_FOREACH(dinfo, &drives, next) {
+ if (dinfo->bdrv == bdrv)
+ return dinfo->queue_depth;
+ }
+
+ return 1;
+}
+
BlockInterfaceErrorAction drive_get_on_error(
BlockDriverState *bdrv, int is_read)
{
@@ -2110,6 +2122,7 @@ DriveInfo *drive_init(QemuOpts *opts, void
*opaque,
const char *devaddr;
DriveInfo *dinfo;
int snapshot = 0;
+ int queue_depth = 1;
*fatal_error = 1;
@@ -2141,6 +2154,7 @@ DriveInfo *drive_init(QemuOpts *opts, void
*opaque,
file = qemu_opt_get(opts, "file");
serial = qemu_opt_get(opts, "serial");
+ queue_depth = qemu_opt_get_number(opts,
"x-queue-depth-suppress-notify",1);
if ((buf = qemu_opt_get(opts, "if")) != NULL) {
pstrcpy(devname, sizeof(devname), buf);
@@ -2375,6 +2389,7 @@ DriveInfo *drive_init(QemuOpts *opts, void
*opaque,
dinfo->on_read_error = on_read_error;
dinfo->on_write_error = on_write_error;
dinfo->opts = opts;
+ dinfo->queue_depth = queue_depth;
if (serial)
strncpy(dinfo->serial, serial, sizeof(serial));
QTAILQ_INSERT_TAIL(&drives, dinfo, next);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [Qemu-devel] [RFC][PATCH v2] suppressing queue notification with queue depth parameter (was: [RFC][PATCH] Queue notify support for virtio block device.)
2010-01-14 10:33 [Qemu-devel] [RFC][PATCH v2] suppressing queue notification with queue depth parameter (was: [RFC][PATCH] Queue notify support for virtio block device.) Vadim Rozenfeld
@ 2010-01-14 14:30 ` Anthony Liguori
0 siblings, 0 replies; 2+ messages in thread
From: Anthony Liguori @ 2010-01-14 14:30 UTC (permalink / raw)
To: Vadim Rozenfeld; +Cc: Dor Laor, qemu-devel, Avi Kivity
On 01/14/2010 04:33 AM, Vadim Rozenfeld wrote:
> The following patch allows to suppress virtio queue notification with
> the number of requests passed as parameter.
>
> Changes from v1:
> - code styling,
> - parameter "x-queue-depth-suppress-notify" for queue depth adjustment.
>
> repository: /home/vadimr/work/upstream/qemu
> branch: master
> commit d23a1c2fbd23e3da9a671a35c95324d2c630e4c9
> Author: Vadim Rozenfeld<vrozenfe@redhat.com>
> Date: Thu Jan 14 08:09:26 2010 +0200
>
> [RFC][PATCH v2] suppressing queue notification with queue depth
> parameter
>
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index cb1ae1f..93b584d 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -28,6 +28,8 @@ typedef struct VirtIOBlock
> char serial_str[BLOCK_SERIAL_STRLEN + 1];
> QEMUBH *bh;
> size_t config_size;
> + unsigned int queue_depth;
> + unsigned int requests;
> } VirtIOBlock;
>
> static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
> @@ -87,6 +89,8 @@ typedef struct VirtIOBlockReq
> struct VirtIOBlockReq *next;
> } VirtIOBlockReq;
>
> +static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue
> *vq);
> +
> static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
> {
> VirtIOBlock *s = req->dev;
> @@ -95,6 +99,11 @@ static void virtio_blk_req_complete(VirtIOBlockReq
> *req, int status)
> virtqueue_push(s->vq,&req->elem, req->qiov.size +
> sizeof(*req->in));
> virtio_notify(&s->vdev, s->vq);
>
> + virtio_blk_handle_output(&s->vdev, s->vq);
> + if (--s->requests == (s->queue_depth - 1)) {
> + virtio_queue_set_notification(s->vq, 1);
> + }
> +
> qemu_free(req);
> }
>
> @@ -340,6 +349,10 @@ static void virtio_blk_handle_output(VirtIODevice
> *vdev, VirtQueue *vq)
> exit(1);
> }
>
> + if (++s->requests == s->queue_depth) {
> + virtio_queue_set_notification(s->vq, 0);
> + }
> +
> req->out = (void *)req->elem.out_sg[0].iov_base;
> req->in = (void *)req->elem.in_sg[req->elem.in_num -
> 1].iov_base;
>
> @@ -502,6 +515,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev,
> DriveInfo *dinfo)
> s->vdev.reset = virtio_blk_reset;
> s->bs = dinfo->bdrv;
> s->rq = NULL;
> + s->queue_depth = drive_get_queue_depth(dinfo->bdrv);
> if (strlen(ps))
> strncpy(s->serial_str, ps, sizeof(s->serial_str));
> else
> diff --git a/qemu-config.c b/qemu-config.c
> index c3203c8..6fcf958 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -78,6 +78,10 @@ QemuOptsList qemu_drive_opts = {
> },{
> .name = "readonly",
> .type = QEMU_OPT_BOOL,
> + },{
> + .name = "x-queue-depth-suppress-notify",
> + .type = QEMU_OPT_NUMBER,
> + .help = "number of requests in queueu before suppressing
> notify",
> },
> { /* end if list */ }
> },
> diff --git a/sysemu.h b/sysemu.h
> index 9d80bb2..6eecbe1 100644
> --- a/sysemu.h
> +++ b/sysemu.h
> @@ -183,6 +183,7 @@ typedef struct DriveInfo {
> BlockInterfaceErrorAction on_read_error;
> BlockInterfaceErrorAction on_write_error;
> char serial[BLOCK_SERIAL_STRLEN + 1];
> + int queue_depth;
> QTAILQ_ENTRY(DriveInfo) next;
> } DriveInfo;
>
> @@ -198,6 +199,7 @@ extern DriveInfo *drive_get_by_id(const char *id);
> extern int drive_get_max_bus(BlockInterfaceType type);
> extern void drive_uninit(DriveInfo *dinfo);
> extern const char *drive_get_serial(BlockDriverState *bdrv);
> +extern int drive_get_queue_depth(BlockDriverState *bdrv);
>
> extern BlockInterfaceErrorAction drive_get_on_error(
> BlockDriverState *bdrv, int is_read);
> diff --git a/vl.c b/vl.c
> index b048e89..517d290 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2043,6 +2043,18 @@ const char *drive_get_serial(BlockDriverState
> *bdrv)
> return "\0";
> }
>
> +int drive_get_queue_depth(BlockDriverState *bdrv)
> +{
> + DriveInfo *dinfo;
> +
> + QTAILQ_FOREACH(dinfo,&drives, next) {
> + if (dinfo->bdrv == bdrv)
> + return dinfo->queue_depth;
> + }
> +
> + return 1;
> +}
> +
> BlockInterfaceErrorAction drive_get_on_error(
> BlockDriverState *bdrv, int is_read)
> {
> @@ -2110,6 +2122,7 @@ DriveInfo *drive_init(QemuOpts *opts, void
> *opaque,
> const char *devaddr;
> DriveInfo *dinfo;
> int snapshot = 0;
> + int queue_depth = 1;
>
It should be disabled by default. queue_depth=1 by default is going to
be devastating for multi-spindle set-ups.
Regards,
Anthony Liguori
^ permalink raw reply [flat|nested] 2+ messages in thread
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2010-01-14 10:33 [Qemu-devel] [RFC][PATCH v2] suppressing queue notification with queue depth parameter (was: [RFC][PATCH] Queue notify support for virtio block device.) Vadim Rozenfeld
2010-01-14 14:30 ` Anthony Liguori
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