From f0bbd602268e69f4f428075c645391d64bdd6c9f Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 28 Sep 2016 13:45:38 -0300 Subject: [PATCH 1/1] perf trace: Beautify sched_[gs]et_attr return value Both return errno, show the string associated then. More work needed to capture the sched_attr arg to beautify it in turn, probably using BPF. Before: 0.210 ( 0.001 ms): sched_setattr(uattr: 0x7ffc684f02b0) = -22 After the patch, for this sched_attr, all other parms are zero, so not shown: struct sched_attr attr = { .size = sizeof(attr), .sched_policy = SCHED_DEADLINE, .sched_runtime = 10 * USECS_PER_SEC, .sched_period = 30 * USECS_PER_SEC, .sched_deadline = attr.sched_period, }; 0.321 ( 0.002 ms): sched_setattr(uattr: 0x7ffc44116da0) = -1 EINVAL Invalid argument [root@jouet c]# perf trace -e sched_setattr ./sched_deadline Couldn't negotiate deadline: Invalid argument 0.229 ( 0.003 ms): sched_setattr(uattr: 0x7ffd8dcd8df0) = -1 EINVAL Invalid argument [root@jouet c]# Now to figure out the reason for this EINVAL. Cc: Adrian Hunter Cc: Clark Williams Cc: Daniel Bristot de Oliveira Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Steven Rostedt Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-tyot2n7e48zm8pdw8tbcm3sl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index b4fc1ab3d2a7..1a54ce9d101c 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -742,6 +742,8 @@ static struct syscall_fmt { .arg_scnprintf = { [1] = SCA_SIGNUM, /* sig */ }, }, { .name = "rt_tgsigqueueinfo", .errmsg = true, .arg_scnprintf = { [2] = SCA_SIGNUM, /* sig */ }, }, + { .name = "sched_getattr", .errmsg = true, }, + { .name = "sched_setattr", .errmsg = true, }, { .name = "sched_setscheduler", .errmsg = true, .arg_scnprintf = { [1] = SCA_SCHED_POLICY, /* policy */ }, }, { .name = "seccomp", .errmsg = true, -- 2.20.1