From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752074AbdJCOm2 (ORCPT ); Tue, 3 Oct 2017 10:42:28 -0400 Received: from merlin.infradead.org ([205.233.59.134]:60948 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751291AbdJCOm1 (ORCPT ); Tue, 3 Oct 2017 10:42:27 -0400 Date: Tue, 3 Oct 2017 16:42:22 +0200 From: Peter Zijlstra To: Alexander Shishkin Cc: Ingo Molnar , linux-kernel@vger.kernel.org, acme@redhat.com, kirill.shutemov@linux.intel.com, Borislav Petkov , rric@kernel.org Subject: Re: [RFC PATCH 08/17] perf: Allow inheritance for detached events Message-ID: <20171003144222.fkwufhowb7lrqwi3@hirez.programming.kicks-ass.net> References: <20170905133026.13689-1-alexander.shishkin@linux.intel.com> <20170905133026.13689-9-alexander.shishkin@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170905133026.13689-9-alexander.shishkin@linux.intel.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 05, 2017 at 04:30:17PM +0300, Alexander Shishkin wrote: > This enables inheritance for detached events. Unlike traditional events, > these do not have parents: inheritance produces a new independent event > with the same attribute. If the 'parent' event has a ring buffer, so will > the new event. Considering the mlock accounting, this buffer allocation > may fail, which in turn will fail the parent's fork, something to be > aware of. > > This also effectively disables context cloning, because unlike the > traditional events, these will each have its own ring buffer and > context switch optimization can't work. Right, so this thing is icky... as you know. More naming issues though, what will you go and call those files.