From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752107AbdJFLlA (ORCPT ); Fri, 6 Oct 2017 07:41:00 -0400 Received: from mga04.intel.com ([192.55.52.120]:46628 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751841AbdJFLk7 (ORCPT ); Fri, 6 Oct 2017 07:40:59 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,483,1500966000"; d="scan'208";a="1179341511" From: Alexander Shishkin To: Peter Zijlstra 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 In-Reply-To: <20171003144222.fkwufhowb7lrqwi3@hirez.programming.kicks-ass.net> References: <20170905133026.13689-1-alexander.shishkin@linux.intel.com> <20170905133026.13689-9-alexander.shishkin@linux.intel.com> <20171003144222.fkwufhowb7lrqwi3@hirez.programming.kicks-ass.net> User-Agent: Notmuch/0.23.7 (http://notmuchmail.org) Emacs/25.1.1 (x86_64-pc-linux-gnu) Date: Fri, 06 Oct 2017 14:40:55 +0300 Message-ID: <87o9pktsfs.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: > 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. Yes. The failing-the-fork ickiness is dealt with later on in 11/17. But true about the naming. Regards, -- Alex