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From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>,
	Ian Rogers <irogers@google.com>, Jiri Olsa <jolsa@kernel.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Clark Williams <williams@redhat.com>,
	Michael Petlan <mpetlan@redhat.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: RFE: perf lock contention --bpf on an RT kernel
Date: Thu, 17 Aug 2023 11:17:55 -0300	[thread overview]
Message-ID: <ZN4sE4eC6C61B3WE@kernel.org> (raw)
In-Reply-To: <ZN4nRfquIsQLx1lV@kernel.org>

Em Thu, Aug 17, 2023 at 10:57:25AM -0300, Arnaldo Carvalho de Melo escreveu:
> Hi Namhyung, I noticed this when trying to use the BPF mode of perf lock
> contention on an RT kernel:
> 
> 
> I tried up to now the following patch, it loads, but produces no output
> :-\

To check that a BPF skel based programs works with this kernel I tried:

[root@nine perf-tools-next]# uname -a
Linux nine 5.14.0-284.18.1.rt14.303.el9_2.x86_64 #1 SMP PREEMPT_RT Wed May 31 13:18:55 EDT 2023 x86_64 x86_64 x86_64 GNU/Linux
[root@nine perf-tools-next]# tools/bpf/runqslower/.output/runqslower 50 | head -20
Tracing run queue latency higher than 50 us
TIME     COMM             PID           LAT(us)
11:13:47 ktimers/5        60                 54
11:13:47 irq_work/5       62                124
11:13:47 ktimers/5        60                 53
11:13:47 irq_work/5       62                 88
11:13:47 swapper/0        3942               59
11:13:47 ktimers/4        52                 55
11:13:47 irq_work/4       54                102
11:13:47 swapper/0        3942               51
11:13:47 ktimers/5        60                 54
11:13:47 irq_work/5       62                 93
11:13:47 swapper/0        3942               51
11:13:47 kworker/2:2      38                141
11:13:47 swapper/4        14                 90
11:13:47 swapper/6        642               102
11:13:47 swapper/7        77                 52
11:13:47 ktimers/7        76                103
11:13:47 irq_work/7       78                 92
11:13:47 ktimers/6        68                 83
[root@nine perf-tools-next]#

- Arnaldo

      reply	other threads:[~2023-08-17 14:18 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-17 13:57 RFE: perf lock contention --bpf on an RT kernel Arnaldo Carvalho de Melo
2023-08-17 14:17 ` Arnaldo Carvalho de Melo [this message]

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