From d7bb72c83cfbcfd0563e158800e4052819223524 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 12 Mar 2012 16:36:07 +0000 Subject: 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 Signed-off-by: Kevin Wolf --- qemu-io.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'qemu-io.c') diff --git a/qemu-io.c b/qemu-io.c index 3189530..e6fcd77 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); -- cgit v1.1