From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manuel Selva Subject: What is the exact meaning of this parameter ? Date: Wed, 27 May 2015 18:55:07 +0200 Message-ID: <5565F6EB.3090406@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:34560 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753403AbbE0QzL (ORCPT ); Wed, 27 May 2015 12:55:11 -0400 Received: by wgv5 with SMTP id 5so15062509wgv.1 for ; Wed, 27 May 2015 09:55:10 -0700 (PDT) Received: from [134.214.61.243] (anyconnect243.insa-lyon.fr. [134.214.61.243]) by mx.google.com with ESMTPSA id js3sm27757786wjc.5.2015.05.27.09.55.08 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 May 2015 09:55:09 -0700 (PDT) Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: "linux-perf-users@vger.kernel.org" Hi all, I know that the perf_event_mlock_kb kernel parameter allows to limit the amount of counters sampling memory that can be mmap'ed by an unprivileged user. Nevertheless, playing with the size I give to mmap some memory using the file descriptor returned by perf_event_open I am not able to linkk with the perf_event_mlock_kb parameter. Looking into kernel sources, it seems this parameter is used in kernel/events/core.c where the perf mmap operation is defined but I am not sure to understand the code there. So my question is what is the exact meaning of this parameter ? -- Manu