From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754626AbbJTWxP (ORCPT ); Tue, 20 Oct 2015 18:53:15 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:36129 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753243AbbJTWxH (ORCPT ); Tue, 20 Oct 2015 18:53:07 -0400 Subject: Re: [PATCH V5 1/1] bpf: control events stored in PERF_EVENT_ARRAY maps trace data output when perf sampling To: Kaixu Xia , davem@davemloft.net, acme@kernel.org, mingo@redhat.com, a.p.zijlstra@chello.nl, masami.hiramatsu.pt@hitachi.com, jolsa@kernel.org, daniel@iogearbox.net References: <1445325735-121694-1-git-send-email-xiakaixu@huawei.com> <1445325735-121694-2-git-send-email-xiakaixu@huawei.com> Cc: wangnan0@huawei.com, linux-kernel@vger.kernel.org, pi3orama@163.com, hekuang@huawei.com, netdev@vger.kernel.org From: Alexei Starovoitov Message-ID: <5626C5CE.8080809@plumgrid.com> Date: Tue, 20 Oct 2015 15:53:02 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1445325735-121694-2-git-send-email-xiakaixu@huawei.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/20/15 12:22 AM, Kaixu Xia wrote: > diff --git a/kernel/events/core.c b/kernel/events/core.c > index b11756f..5219635 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -6337,6 +6337,9 @@ static int __perf_event_overflow(struct perf_event *event, > irq_work_queue(&event->pending); > } > > + if (unlikely(!atomic_read(&event->soft_enable))) > + return 0; > + > if (event->overflow_handler) > event->overflow_handler(event, data, regs); > else Peter, does this part look right or it should be moved right after if (unlikely(!is_sampling_event(event))) return 0; or even to other function? It feels to me that it should be moved, since we probably don't want to active throttling, period adjust and event_limit for events that are in soft_disabled state.