From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
To: Dipen Patel <dipenp@nvidia.com>
Cc: linux-rt-users@vger.kernel.org
Subject: Re: Multi pthreaded RT application - mlock doubt
Date: Tue, 25 May 2021 09:26:58 +0200 [thread overview]
Message-ID: <YKymwnknCImO30CU@lx-t490> (raw)
In-Reply-To: <896cf71c-f610-961a-9d30-8a82d433e0f6@nvidia.com>
On Wed, Mar 31, 2021 at 07:06:26PM -0700, Dipen Patel wrote:
> Hi,
>
> I was following
> https://rt.wiki.kernel.org/index.php/Threaded_RT-application_with_memory_locking_and_stack_handling_example
> with some below changes:
>
The example above is a bit inaccurate, as it prefaults the thread's
stack much later than it should be.
...
>
> thread_fn {
> getrusage(RUSAGE_SELF, &usage);>
> print and save usage.ruminflt;
> prove_thread_stack_use_is_safe
> getrusage(RUSAGE_SELF, &usage);
> print usage.ruminflt - last_saved_cnt;
> }
>
> I observed there are still page faults.
Well, in the snippet above, there will obviously be page faults, as
you're also measuring the faults generated by
prove_thread_stack_use_is_safe(). On first invocation, this is actually
the method prefaulting the thread stack.
To make sure the discussion is more concrete, can you please send a
complete, compilable, *.c file?
Good luck,
--
Ahmed S. Darwish
Linutronix GmbH
next prev parent reply other threads:[~2021-05-25 7:27 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 2:06 Multi pthreaded RT application - mlock doubt Dipen Patel
2021-05-25 3:08 ` Dipen Patel
2021-05-25 7:26 ` Ahmed S. Darwish [this message]
2021-05-25 22:24 ` Dipen Patel
2021-05-26 8:31 ` Ahmed S. Darwish
2021-05-26 10:26 ` John Ogness
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