linux-rt-users.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dipen Patel <dipenp@nvidia.com>
To: <linux-rt-users@vger.kernel.org>
Subject: Multi pthreaded RT application - mlock doubt
Date: Wed, 31 Mar 2021 19:06:26 -0700	[thread overview]
Message-ID: <896cf71c-f610-961a-9d30-8a82d433e0f6@nvidia.com> (raw)

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:

1. Added 8 threads
2. Moved show_new_pagefault_count logic inside thread function once thread starts running as below:

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 (although not in big numbers as if there was no mlock), after touching stack in prove_thread_stack_use_is_safe call. I played around with MY_STACK_SIZE (from 1KB to 1MB) but still see minor page faults.

I am running 4.9.201_rt134 kernel. Any idea what I will be missing?

Best Regards,
Dipen Patel

             reply	other threads:[~2021-04-01  2:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01  2:06 Dipen Patel [this message]
2021-05-25  3:08 ` Multi pthreaded RT application - mlock doubt Dipen Patel
2021-05-25  7:26 ` Ahmed S. Darwish
2021-05-25 22:24   ` Dipen Patel
2021-05-26  8:31     ` Ahmed S. Darwish
2021-05-26 10:26       ` John Ogness

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=896cf71c-f610-961a-9d30-8a82d433e0f6@nvidia.com \
    --to=dipenp@nvidia.com \
    --cc=linux-rt-users@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).