From: Yang Jihong yangjihong1@huawei.com
[ Upstream commit ecd4960d908e27e40b63a7046df2f942c148c6f6 ]
If no target is specified for 'latency' subcommand, the execution fails because - 1 (invalid value) is written to set_ftrace_pid tracefs file. Make system wide the default target, which is the same as the default behavior of 'trace' subcommand.
Before the fix:
# perf ftrace latency -T schedule failed to set ftrace pid
After the fix:
# perf ftrace latency -T schedule ^C# DURATION | COUNT | GRAPH | 0 - 1 us | 0 | | 1 - 2 us | 0 | | 2 - 4 us | 0 | | 4 - 8 us | 2828 | #### | 8 - 16 us | 23953 | ######################################## | 16 - 32 us | 408 | | 32 - 64 us | 318 | | 64 - 128 us | 4 | | 128 - 256 us | 3 | | 256 - 512 us | 0 | | 512 - 1024 us | 1 | | 1 - 2 ms | 4 | | 2 - 4 ms | 0 | | 4 - 8 ms | 0 | | 8 - 16 ms | 0 | | 16 - 32 ms | 0 | | 32 - 64 ms | 0 | | 64 - 128 ms | 0 | | 128 - 256 ms | 4 | | 256 - 512 ms | 2 | | 512 - 1024 ms | 0 | | 1 - ... s | 0 | |
Fixes: 53be50282269b46c ("perf ftrace: Add 'latency' subcommand") Signed-off-by: Yang Jihong yangjihong1@huawei.com Acked-by: Namhyung Kim namhyung@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ian Rogers irogers@google.com Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Peter Zijlstra peterz@infradead.org Link: https://lore.kernel.org/r/20230324032702.109964-1-yangjihong1@huawei.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-ftrace.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 7de07bb16d235..4bc5b7cf3e04b 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -1228,10 +1228,12 @@ int cmd_ftrace(int argc, const char **argv) goto out_delete_filters; }
+ /* Make system wide (-a) the default target. */ + if (!argc && target__none(&ftrace.target)) + ftrace.target.system_wide = true; + switch (subcmd) { case PERF_FTRACE_TRACE: - if (!argc && target__none(&ftrace.target)) - ftrace.target.system_wide = true; cmd_func = __cmd_ftrace; break; case PERF_FTRACE_LATENCY: