[PATCH 5/5] trace: Trace virtio-blk, multiwrite, and paio_submit

Stefan Hajnoczi
2010-05-22T21:08:37Z

This patch adds trace events that make it possible to observe
virtio-blk.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
block.c | 7 +++++++
hw/virtio-blk.c | 7 +++++++
posix-aio-compat.c | 2 ++
trace-events | 14 ++++++++++++++
4 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/block.c b/block.c
index bfe46e3..86fe7f5 100644
--- a/block.c
+++ b/block.c
@@ -23,6 +23,7 @@
*/
#include "config-host.h"
#include "qemu-common.h"
+#include "trace.h"
#include "monitor.h"
#include "block_int.h"
#include "module.h"
@@ -1913,6 +1914,8 @@ static void multiwrite_cb(void *opaque, int ret)
{
MultiwriteCB *mcb = opaque;

+ trace_multiwrite_cb(mcb, ret);
+
if (ret < 0 && !mcb->error) {
mcb->error = ret;
multiwrite_user_cb(mcb);
@@ -2044,6 +2047,8 @@ int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
// Check for mergable requests
num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);

+ trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
+
// Run the aio requests
for (i = 0; i < num_reqs; i++) {
acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
@@ -2054,9 +2059,11 @@ int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
// submitted yet. Otherwise we'll wait for the submitted AIOs to
// complete and report the error in the callback.
if (mcb->num_requests == 0) {
+ trace_bdrv_aio_multiwrite_earlyfail(mcb);
reqs[i].error = -EIO;
goto fail;
} else {
+ trace_bdrv_aio_multiwrite_latefail(mcb, i);
mcb->num_requests++;
multiwrite_cb(mcb, -EIO);
break;
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index b05d15e..ef384e0 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -13,6 +13,7 @@

#include <qemu-common.h>
#include <sysemu.h>
+#include "trace.h"
#include "virtio-blk.h"
#include "block_int.h"
#ifdef __linux__
@@ -50,6 +51,8 @@ static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
{
VirtIOBlock *s = req->dev;

+ trace_virtio_blk_req_complete(req, status);
+
req->in->status = status;
virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
virtio_notify(&s->vdev, s->vq);
@@ -87,6 +90,8 @@ static void virtio_blk_rw_complete(void *opaque, int ret)
{
VirtIOBlockReq *req = opaque;

+ trace_virtio_blk_rw_complete(req, ret);
+
if (ret) {
int is_read = !(req->out->type & VIRTIO_BLK_T_OUT);
if (virtio_blk_handle_rw_error(req, -ret, is_read))
@@ -251,6 +256,8 @@ static void virtio_blk_handle_flush(VirtIOBlockReq *req)
static void virtio_blk_handle_write(BlockRequest *blkreq, int *num_writes,
VirtIOBlockReq *req, BlockDriverState **old_bs)
{
+ trace_virtio_blk_handle_write(req, req->out->sector, req->qiov.size / 512);
+
if (req->out->sector & req->dev->sector_mask) {
virtio_blk_rw_complete(req, -EIO);
return;
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index b43c531..c2200fe 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -25,6 +25,7 @@
#include "qemu-queue.h"
#include "osdep.h"
#include "qemu-common.h"
+#include "trace.h"
#include "block_int.h"

#include "block/raw-posix-aio.h"
@@ -583,6 +584,7 @@ BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd,
acb->next = posix_aio_state->first_aio;
posix_aio_state->first_aio = acb;

+ trace_paio_submit(acb, opaque, sector_num, nb_sectors, type);
qemu_paio_submit(acb);
return &acb->common;
}
diff --git a/trace-events b/trace-events
index a93ea29..4d96b8e 100644
--- a/trace-events
+++ b/trace-events
@@ -32,3 +32,17 @@ qemu_free(void *ptr) "ptr %p"
qemu_memalign(size_t alignment, size_t size) "alignment %zu size %zu"
qemu_valloc(size_t size) "size %zu"
qemu_vfree(void *ptr) "ptr %p"
+
+# block.c
+multiwrite_cb(void *mcb, int ret) "mcb %p ret %d"
+bdrv_aio_multiwrite(void *mcb, int num_callbacks, int num_reqs) "mcb %p num_callbacks %d num_reqs %d"
+bdrv_aio_multiwrite_earlyfail(void *mcb) "mcb %p"
+bdrv_aio_multiwrite_latefail(void *mcb, int i) "mcb %p i %d"
+
+# hw/virtio-blk.c
+virtio_blk_req_complete(void *req, int status) "req %p status %d"
+virtio_blk_rw_complete(void *req, int ret) "req %p ret %d"
+virtio_blk_handle_write(void *req, unsigned long sector, unsigned long nsectors) "req %p sector %lu nsectors %lu"
+
+# posix-aio-compat.c
+paio_submit(void *acb, void *opaque, unsigned long sector_num, unsigned long nb_sectors, unsigned long type) "acb %p opaque %p sector_num %lu nb_sectors %lu type %lu"
--
1.7.1