From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933271AbcBYQpw (ORCPT ); Thu, 25 Feb 2016 11:45:52 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:41042 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932381AbcBYQpu (ORCPT ); Thu, 25 Feb 2016 11:45:50 -0500 Date: Thu, 25 Feb 2016 17:45:38 +0100 From: Peter Zijlstra To: Alexei Starovoitov Cc: "David S. Miller" , Ingo Molnar , Steven Rostedt , Wang Nan , Daniel Borkmann , Brendan Gregg , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next 1/3] perf: generalize perf_callchain Message-ID: <20160225164538.GR6356@twins.programming.kicks-ass.net> References: <1455767939-2700534-1-git-send-email-ast@fb.com> <1455767939-2700534-2-git-send-email-ast@fb.com> <20160225141859.GM6357@twins.programming.kicks-ass.net> <56CF2DCE.5010501@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56CF2DCE.5010501@fb.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 25, 2016 at 08:37:34AM -0800, Alexei Starovoitov wrote: > On 2/25/16 6:18 AM, Peter Zijlstra wrote: > >On Wed, Feb 17, 2016 at 07:58:57PM -0800, Alexei Starovoitov wrote: > >>. avoid walking the stack when there is no room left in the buffer > >>. generalize get_perf_callchain() to be called from bpf helper > > > >If it does two things it should be two patches. > > could have been two patches, but it will only add more churn > to the same lines. what's the concern? It makes review easier, shows which modification is for what purpose. Also the changelog really needs more; it should for example explain what BPF needs from the callchain code, and preferably why.