[PATCH 2/2] trace: Trace write requests in virtio-blk, multiwrite, and paio_submit

Stefan Hajnoczi
2010-05-21T09:42:39Z

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
block.c | 7 +++++++
hw/virtio-blk.c | 6 ++++++
posix-aio-compat.c | 2 ++
trace.h | 42 +++++++++++++++++++++++++++++++++++++++++-
trace.py | 8 ++++++++
5 files changed, 64 insertions(+), 1 deletions(-)

diff --git a/block.c b/block.c
index bfe46e3..a7fb040 100644
--- a/block.c
+++ b/block.c
@@ -27,6 +27,7 @@
#include "block_int.h"
#include "module.h"
#include "qemu-objects.h"
+#include "trace.h"

#ifdef CONFIG_BSD
#include <sys/types.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..73b873e 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))
@@ -270,6 +275,7 @@ static void virtio_blk_handle_write(BlockRequest *blkreq, int *num_writes,
blkreq[*num_writes].cb = virtio_blk_rw_complete;
blkreq[*num_writes].opaque = req;
blkreq[*num_writes].error = 0;
+ trace_virtio_blk_handle_write(req, req->out->sector, req->qiov.size / 512);

(*num_writes)++;
}
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index b43c531..57d83f0 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -23,6 +23,7 @@
#include <stdio.h>

#include "qemu-queue.h"
+#include "trace.h"
#include "osdep.h"
#include "qemu-common.h"
#include "block_int.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.h b/trace.h
index 144aa1e..3c4564f 100644
--- a/trace.h
+++ b/trace.h
@@ -1,5 +1,12 @@
typedef enum {
- TRACE_MAX
+ TRACE_MULTIWRITE_CB,
+ TRACE_BDRV_AIO_MULTIWRITE,
+ TRACE_BDRV_AIO_MULTIWRITE_EARLYFAIL,
+ TRACE_BDRV_AIO_MULTIWRITE_LATEFAIL,
+ TRACE_VIRTIO_BLK_REQ_COMPLETE,
+ TRACE_VIRTIO_BLK_RW_COMPLETE,
+ TRACE_VIRTIO_BLK_HANDLE_WRITE,
+ TRACE_PAIO_SUBMIT,
} TraceEvent;

void trace1(TraceEvent event, unsigned long x1);
@@ -7,3 +14,36 @@ void trace2(TraceEvent event, unsigned long x1, unsigned long x2);
void trace3(TraceEvent event, unsigned long x1, unsigned long x2, unsigned long x3);
void trace4(TraceEvent event, unsigned long x1, unsigned long x2, unsigned long x3, unsigned long x4);
void trace5(TraceEvent event, unsigned long x1, unsigned long x2, unsigned long x3, unsigned long x4, unsigned long x5);
+
+static inline void trace_multiwrite_cb(void *mcb, int ret) {
+ trace2(TRACE_MULTIWRITE_CB, (unsigned long)mcb, ret);
+}
+
+static inline void trace_bdrv_aio_multiwrite(void *mcb, int num_callbacks, int num_reqs) {
+ trace3(TRACE_BDRV_AIO_MULTIWRITE, (unsigned long)mcb, num_callbacks, num_reqs);
+}
+
+static inline void trace_bdrv_aio_multiwrite_earlyfail(void *mcb) {
+ trace1(TRACE_BDRV_AIO_MULTIWRITE_EARLYFAIL, (unsigned long)mcb);
+}
+
+static inline void trace_bdrv_aio_multiwrite_latefail(void *mcb, int i) {
+ trace2(TRACE_BDRV_AIO_MULTIWRITE_LATEFAIL, (unsigned long)mcb, i);
+}
+
+static inline void trace_virtio_blk_req_complete(void *req, int status) {
+ trace2(TRACE_VIRTIO_BLK_REQ_COMPLETE, (unsigned long)req, status);
+}
+
+static inline void trace_virtio_blk_rw_complete(void *req, int ret) {
+ trace2(TRACE_VIRTIO_BLK_RW_COMPLETE, (unsigned long)req, ret);
+}
+
+static inline void trace_virtio_blk_handle_write(void *req, unsigned long sector, unsigned long nsectors) {
+ trace3(TRACE_VIRTIO_BLK_HANDLE_WRITE, (unsigned long)req, sector, nsectors);
+}
+
+static inline void trace_paio_submit(void *acb, void *opaque, unsigned long sector_num, unsigned long nb_sectors, unsigned long type)
+{
+ trace5(TRACE_PAIO_SUBMIT, (unsigned long)acb, (unsigned long)opaque, sector_num, nb_sectors, type);
+}
diff --git a/trace.py b/trace.py
index f38ab6b..ba4476c 100755
--- a/trace.py
+++ b/trace.py
@@ -6,6 +6,14 @@ trace_fmt = 'LLLLLL'
trace_len = struct.calcsize(trace_fmt)

events = {
+ 0: ('multiwrite_cb', 'mcb', 'ret'),
+ 1: ('bdrv_aio_multiwrite', 'mcb', 'num_callbacks', 'num_reqs'),
+ 2: ('bdrv_aio_multiwrite_earlyfail', 'mcb'),
+ 3: ('bdrv_aio_multiwrite_latefail', 'mcb', 'i'),
+ 4: ('virtio_blk_req_complete', 'req', 'status'),
+ 5: ('virtio_blk_rw_complete', 'req', 'ret'),
+ 6: ('virtio_blk_handle_write', 'req', 'sector', 'nsectors'),
+ 7: ('paio_submit', 'acb', 'opaque', 'sector_num', 'nb_sectors', 'type'),
}

def read_record(fobj):
--
1.7.1