Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752242AbdGDJqU (ORCPT ); Tue, 4 Jul 2017 05:46:20 -0400 Received: from merlin.infradead.org ([205.233.59.134]:49586 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751954AbdGDJqS (ORCPT ); Tue, 4 Jul 2017 05:46:18 -0400 Date: Tue, 4 Jul 2017 11:46:02 +0200 From: Peter Zijlstra To: Mark Rutland Cc: Kyle Huey , Vince Weaver , "Jin, Yao" , Ingo Molnar , stable@vger.kernel.org, Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Namhyung Kim , Stephane Eranian , Thomas Gleixner , acme@kernel.org, jolsa@kernel.org, kan.liang@intel.com, Will Deacon , gregkh@linuxfoundation.org, "Robert O'Callahan" , open list Subject: Re: [PATCH] perf/core: generate overflow signal when samples are dropped (WAS: Re: [REGRESSION] perf/core: PMU interrupts dropped if we entered the kernel in the "skid" region) Message-ID: <20170704094602.dgrdwydui3wimf2s@hirez.programming.kicks-ass.net> References: <2256f9b5-1277-c4b1-1472-61a10cd1db9a@linux.intel.com> <20170628101248.GB5981@leverpostej> <20170628105600.GC5981@leverpostej> <20170628174900.GG8252@leverpostej> <20170704090313.xyb5lntyy55ga7dm@hirez.programming.kicks-ass.net> <20170704093345.GB19649@leverpostej> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170704093345.GB19649@leverpostej> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 384 Lines: 12 On Tue, Jul 04, 2017 at 10:33:45AM +0100, Mark Rutland wrote: > > That said, with a per-cpu event the TID sample value is indeed subject > > to skid like you describe. > > For per-cpu events, does that matter? Those don't have TID filters in > the first place, no? eBPF can do all sorts I suppose. But yes, at some point you just have to give up, there's only so much one can do.