[PATCH 16/16] perf kvm: set live mode refresh time dynamically

David Ahern
2013-05-26T00:27:10Z

David's patch (https://lkml.org/lkml/2013/5/9/125 ) add a live mode for
perf kvm stat, but his patch can't set the refresh frequency
dynamically.

This patch accepts user's input and changes the value of
kvm->display_time variable.

For example, when the live mode is running, you press any key, it will
prints:

Mapped keys:
[d] set refresh frequency
[q] quit

Enter selection, or unmapped key to continue:
Enter refresh frequency(seconds): 2

Then, the live mode will refresh the screen every 2 seconds.

Signed-off-by: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
tools/perf/builtin-kvm.c | 42 ++++++++++++++++++++++++++++++++++++++----
tools/perf/util/top.c | 4 ++++
2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 7392538..3e3f6e2 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -111,7 +111,7 @@ struct perf_kvm_stat {
struct rb_root result;

int timerfd;
- unsigned int display_time;
+ int display_time;
bool live;
};

@@ -1021,17 +1021,51 @@ static int fd_set_nonblock(int fd)
return 0;
}

+static void perf_kvm_live__print_mapped_keys(void)
+{
+ fprintf(stdout, "\nMapped keys:\n");
+ fprintf(stdout, "\t[d] set refresh frequency\n");
+ fprintf(stdout, "\t[q] quit\n");
+}
+
static
-int perf_kvm__handle_stdin(struct termios *tc_now, struct termios *tc_save)
+int perf_kvm__handle_stdin(struct perf_kvm_stat *kvm,
+ struct termios *tc_now,
+ struct termios *tc_save)
{
int c;
+ struct pollfd stdin_poll = { .fd = 0, .events = POLLIN};

tcsetattr(0, TCSANOW, tc_now);
c = getc(stdin);
tcsetattr(0, TCSAFLUSH, tc_save);

+ if (c == -1)
+ return 0;
if (c == 'q')
return 1;
+ perf_kvm_live__print_mapped_keys();
+ fprintf(stdout, "\nEnter selection, or unmapped key to continue: ");
+ fflush(stdout);
+
+ tcsetattr(0, TCSANOW, tc_now);
+ poll(&stdin_poll, 1, -1);
+ c = getc(stdin);
+ tcsetattr(0, TCSAFLUSH, tc_save);
+
+ switch (c) {
+ case 'q':
+ return 1;
+ case 'd':
+ prompt_integer(&kvm->display_time,
+ "Enter refresh frequency(seconds)");
+ if (kvm->display_time < 1)
+ kvm->display_time = 1;
+ if (perf_kvm__timerfd_set(kvm) < 0)
+ return 1;
+ default:
+ break;
+ }

return 0;
}
@@ -1108,7 +1142,7 @@ static int kvm_events_live_report(struct perf_kvm_stat *kvm)
goto out;

if (pollfds[nr_stdin].revents & POLLIN)
- done = perf_kvm__handle_stdin(&tc, &save);
+ done = perf_kvm__handle_stdin(kvm, &tc, &save);

if (!rc && !done)
err = poll(pollfds, nr_fds, 100);
@@ -1349,7 +1383,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
"be more verbose (show counter open errors, etc)"),
OPT_BOOLEAN('a', "all-cpus", &kvm->opts.target.system_wide,
"system-wide collection from all CPUs"),
- OPT_UINTEGER('d', "display", &kvm->display_time,
+ OPT_INTEGER('d', "display", &kvm->display_time,
"time in seconds between display updates"),
OPT_STRING(0, "event", &kvm->report_event, "report event",
"event for reporting: vmexit, mmio, ioport"),
diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index 1a2eaec..10bff6d 100644
--- a/tools/perf/util/top.c
+++ b/tools/perf/util/top.c
@@ -121,8 +121,12 @@ void prompt_integer(int *target, const char *msg)
char *buf = malloc(0), *p;
size_t dummy = 0;
int tmp;
+ struct pollfd stdin_poll = { .fd = 0, .events = POLLIN};

fprintf(stdout, "\n%s: ", msg);
+ fflush(stdout);
+ poll(&stdin_poll, 1, -1);
+
if (getline(&buf, &dummy, stdin) < 0)
return;

--
1.7.10.1