perf: avoid assertion for -p option in perf stat -a
PATCH 1/1 perf: avoid assertion for -p option in perf stat -a
It was possible to use perf stat in system-wide mode with -a and still attach to a process (-p) or thread (-t). The issue is that it is not possible to get a termination signal from the attached task, thus the command never terminates. Furthermore, passing -p -a was triggering the assertion in read_counter().
This patch fixes the issue by aborting perf stat if the parameters conflict.
Signed-off-by Stephane Eranian <[email protected]>
tools/perf/builtin-stat.c +8 -0
@@ -573,6 +573,14 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)else nr_cpus =1 ; +/* +* a system-wide session cannot be delimited via an attachment +* because we cannot get a termination notification. +* It also triggers the assertion in read_counter() +*/ +if (system_wide && (target_tid !=-1 || target_pid !=-1 )) +usage_with_options (stat_usage, options); +if (nr_cpus <1 )usage_with_options (stat_usage, options);