From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933260AbeBUKc4 (ORCPT ); Wed, 21 Feb 2018 05:32:56 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:51802 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932751AbeBUKcx (ORCPT ); Wed, 21 Feb 2018 05:32:53 -0500 Date: Wed, 21 Feb 2018 11:32:47 +0100 From: Peter Zijlstra To: kan.liang@linux.intel.com Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, acme@kernel.org, tglx@linutronix.de, jolsa@redhat.com, eranian@google.com, ak@linux.intel.com Subject: Re: [PATCH V4 1/5] perf/x86/intel: Fix event update for auto-reload Message-ID: <20180221103247.GL25181@hirez.programming.kicks-ass.net> References: <1518474035-21006-1-git-send-email-kan.liang@linux.intel.com> <1518474035-21006-2-git-send-email-kan.liang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1518474035-21006-2-git-send-email-kan.liang@linux.intel.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 12, 2018 at 02:20:31PM -0800, kan.liang@linux.intel.com wrote: > @@ -1389,8 +1456,22 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) > > ds->pebs_index = ds->pebs_buffer_base; > > - if (unlikely(base >= top)) > + if (unlikely(base >= top)) { > + /* > + * The drain_pebs() could be called twice in a short period > + * for auto-reload event in pmu::read(). There are no > + * overflows have happened in between. > + * It needs to call intel_pmu_save_and_restart_reload() to > + * update the event->count for this case. > + */ > + for_each_set_bit(bit, (unsigned long *)&cpuc->pebs_enabled, > + x86_pmu.max_pebs_events) { > + event = cpuc->events[bit]; > + if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD) > + intel_pmu_save_and_restart_reload(event, 0); > + } > return; > + } > > for (at = base; at < top; at += x86_pmu.pebs_record_size) { > struct pebs_record_nhm *p = at; Is there a reason you didn't do intel_pmu_drain_pebs_core() ? --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1435,8 +1435,11 @@ static void intel_pmu_drain_pebs_core(st return; n = top - at; - if (n <= 0) + if (n <= 0) { + if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD) + intel_pmu_save_and_restart_reload(event, 0); return; + } __intel_pmu_pebs_event(event, iregs, at, top, 0, n); }