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Date: Thu, 16 Jan 2025 19:46:21 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Tomas Glozar <tglozar@redhat.com>
Cc: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, John
 Kacur <jkacur@redhat.com>, Luis Goncalves <lgoncalv@redhat.com>, Gabriele
 Monaco <gmonaco@redhat.com>
Subject: Re: [PATCH 0/5] rtla/timerlat: Stop on signal properly when
 overloaded
Message-ID: <20250116194621.7b309aed@gandalf.local.home>
In-Reply-To: <20250116144931.649593-1-tglozar@redhat.com>
References: <20250116144931.649593-1-tglozar@redhat.com>
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On Thu, 16 Jan 2025 15:49:26 +0100
Tomas Glozar <tglozar@redhat.com> wrote:

> In the future, two more patchsets will be sent: one to display how many
> events/samples were dropped (either left in tracefs buffer or by buffer
> overflow), one to improve sample processing performance to be on par with
> cyclictest (ideally) so that samples are not dropped in the cases mentioned
> in the beginning of the email.

Hmm, I wonder if timerlat can handle per cpu data, then you could kick off
a thread per CPU (or a set of CPUs) where the thread is responsible for
handling the data.


		CPU_ZERO_S(cpu_size, cpusetp);
		CPU_SET_S(cpu, cpu_size, cpusetp);
                retval = tracefs_iterate_raw_events(trace->tep,
                                trace->inst,
                                cpusetp,
                                cpu_size,
                                collect_registered_events,
                                                    trace);

And then that iteration will only read over a subset of CPUs. Each thread
can do a different subset and then it should be able to keep up.

-- Steve