From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751915AbdGOBlT (ORCPT ); Fri, 14 Jul 2017 21:41:19 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:29982 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751394AbdGOB1P (ORCPT ); Fri, 14 Jul 2017 21:27:15 -0400 X-IronPort-Anti-Spam-Filtered: false From: "Levin, Alexander (Sasha Levin)" Cc: Daniel Bristot de Oliveira , Alexander Shishkin , Jiri Olsa , "Peter Zijlstra" , Arnaldo Carvalho de Melo , "Levin, Alexander (Sasha Levin)" X-Host: discovery.odc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH for v4.9 LTS 39/87] tools lib traceevent: Fix prev/next_prio for deadline tasks Thread-Topic: [PATCH for v4.9 LTS 39/87] tools lib traceevent: Fix prev/next_prio for deadline tasks Thread-Index: AQHS/QlXEbLerxzj70urpvbFb9hgQA== Date: Sat, 15 Jul 2017 01:26:10 +0000 Message-ID: <20170715012538.10101-39-alexander.levin@verizon.com> References: <20170715012538.10101-1-alexander.levin@verizon.com> In-Reply-To: <20170715012538.10101-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v6F1fOAS023309 From: Daniel Bristot de Oliveira [ Upstream commit 074859184d770824f4437dca716bdeb625ae8b1c ] Currently, the sched:sched_switch tracepoint reports deadline tasks with priority -1. But when reading the trace via perf script I've got the following output: # ./d & # (d is a deadline task, see [1]) # perf record -e sched:sched_switch -a sleep 1 # perf script ... swapper 0 [000] 2146.962441: sched:sched_switch: swapper/0:0 [120] R ==> d:2593 [4294967295] d 2593 [000] 2146.972472: sched:sched_switch: d:2593 [4294967295] R ==> g:2590 [4294967295] The task d reports the wrong priority [4294967295]. This happens because the "int prio" is stored in an unsigned long long val. Although it is set as a %lld, as int is shorter than unsigned long long, trace_seq_printf prints it as a positive number. The fix is just to cast the val as an int, and print it as a %d, as in the sched:sched_switch tracepoint's "format". The output with the fix is: # ./d & # perf record -e sched:sched_switch -a sleep 1 # perf script ... swapper 0 [000] 4306.374037: sched:sched_switch: swapper/0:0 [120] R ==> d:10941 [-1] d 10941 [000] 4306.383823: sched:sched_switch: d:10941 [-1] R ==> swapper/0:0 [120] [1] d.c --- #include #include #include #include #include struct sched_attr { __u32 size, sched_policy; __u64 sched_flags; __s32 sched_nice; __u32 sched_priority; __u64 sched_runtime, sched_deadline, sched_period; }; int sched_setattr(pid_t pid, const struct sched_attr *attr, unsigned int flags) { return syscall(__NR_sched_setattr, pid, attr, flags); } int main(void) { struct sched_attr attr = { .size = sizeof(attr), .sched_policy = SCHED_DEADLINE, /* This creates a 10ms/30ms reservation */ .sched_runtime = 10 * 1000 * 1000, .sched_period = attr.sched_deadline = 30 * 1000 * 1000, }; if (sched_setattr(0, &attr, 0) < 0) { perror("sched_setattr"); return -1; } for(;;); } --- Committer notes: Got the program from the provided URL, http://bristot.me/lkml/d.c, trimmed it and included in the cset log above, so that we have everything needed to test it in one place. Signed-off-by: Daniel Bristot de Oliveira Acked-by: Steven Rostedt Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Daniel Bristot de Oliveira Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/866ef75bcebf670ae91c6a96daa63597ba981f0d.1483443552.git.bristot@redhat.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/lib/traceevent/plugin_sched_switch.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/traceevent/plugin_sched_switch.c b/tools/lib/traceevent/plugin_sched_switch.c index f1ce60065258..ec30c2fcbac0 100644 --- a/tools/lib/traceevent/plugin_sched_switch.c +++ b/tools/lib/traceevent/plugin_sched_switch.c @@ -111,7 +111,7 @@ static int sched_switch_handler(struct trace_seq *s, trace_seq_printf(s, "%lld ", val); if (pevent_get_field_val(s, event, "prev_prio", record, &val, 0) == 0) - trace_seq_printf(s, "[%lld] ", val); + trace_seq_printf(s, "[%d] ", (int) val); if (pevent_get_field_val(s, event, "prev_state", record, &val, 0) == 0) write_state(s, val); @@ -129,7 +129,7 @@ static int sched_switch_handler(struct trace_seq *s, trace_seq_printf(s, "%lld", val); if (pevent_get_field_val(s, event, "next_prio", record, &val, 0) == 0) - trace_seq_printf(s, " [%lld]", val); + trace_seq_printf(s, " [%d]", (int) val); return 0; } -- 2.11.0