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authorStefan Hajnoczi <stefanha@linux.vnet.ibm.com>2012-03-12 16:36:07 +0000
committerKevin Wolf <kwolf@redhat.com>2012-04-05 14:54:39 +0200
commitd7bb72c83cfbcfd0563e158800e4052819223524 (patch)
treebb36b10cc9460fee6d78d0bc89eb4b112fb36b13
parent3948d1d4876065160583e79533bf604481063833 (diff)
qemu-io: add option to enable tracing
It can be useful to enable QEMU tracing when trying out block layer interfaces via qemu-io. Tracing can be enabled using the new -T FILE option where the given file contains a list of trace events to enable (just like the qemu --trace events=FILE option). $ echo qemu_vfree >my-events $ ./qemu-io -T my-events ... Remember to use ./configure --enable-trace-backend=BACKEND when building qemu-io. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--qemu-io.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/qemu-io.c b/qemu-io.c
index 31895305f1..e6fcd7719e 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -17,6 +17,7 @@
#include "qemu-common.h"
#include "block_int.h"
#include "cmd.h"
+#include "trace/control.h"
#define VERSION "0.0.1"
@@ -1783,6 +1784,7 @@ static void usage(const char *name)
" -g, --growable allow file to grow (only applies to protocols)\n"
" -m, --misalign misalign allocations for O_DIRECT\n"
" -k, --native-aio use kernel AIO implementation (on Linux only)\n"
+" -T, --trace FILE enable trace events listed in the given file\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
"\n",
@@ -1794,7 +1796,7 @@ int main(int argc, char **argv)
{
int readonly = 0;
int growable = 0;
- const char *sopt = "hVc:rsnmgk";
+ const char *sopt = "hVc:rsnmgkT:";
const struct option lopt[] = {
{ "help", 0, NULL, 'h' },
{ "version", 0, NULL, 'V' },
@@ -1806,6 +1808,7 @@ int main(int argc, char **argv)
{ "misalign", 0, NULL, 'm' },
{ "growable", 0, NULL, 'g' },
{ "native-aio", 0, NULL, 'k' },
+ { "trace", 1, NULL, 'T' },
{ NULL, 0, NULL, 0 }
};
int c;
@@ -1837,6 +1840,11 @@ int main(int argc, char **argv)
case 'k':
flags |= BDRV_O_NATIVE_AIO;
break;
+ case 'T':
+ if (!trace_backend_init(optarg, NULL)) {
+ exit(1); /* error message will have been printed */
+ }
+ break;
case 'V':
printf("%s version %s\n", progname, VERSION);
exit(0);