From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751469AbbJVFAS (ORCPT ); Thu, 22 Oct 2015 01:00:18 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:33626 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767AbbJVFAQ (ORCPT ); Thu, 22 Oct 2015 01:00:16 -0400 Subject: Re: [PATCH v2 net-next] bpf: fix bpf_perf_event_read() helper To: "Wangnan (F)" , "David S. Miller" References: <1445468283-4592-1-git-send-email-ast@kernel.org> <56286ACD.3060604@huawei.com> Cc: Ingo Molnar , Peter Zijlstra , He Kuang , Kaixu Xia , Daniel Borkmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Alexei Starovoitov Message-ID: <56286D5C.2060009@plumgrid.com> Date: Wed, 21 Oct 2015 22:00:12 -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: <56286ACD.3060604@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/21/15 9:49 PM, Wangnan (F) wrote: > After applying this patch I'm unable to use perf passing perf_event > again like this: please do not top post and trim your replies. > # perf record -a -e evt=cycles -e > ./test_config_map.c/maps.pmu_map.event=evt/ --exclude-perf ls > > With -v it output: > > ... > adding perf_bpf_probe:func_write > adding perf_bpf_probe:func_write to 0x367d6a0 > add bpf event perf_bpf_probe:func_write_return and attach bpf program 6 > adding perf_bpf_probe:func_write_return > adding perf_bpf_probe:func_write_return to 0x3a7fc40 > mmap size 528384B > ERROR: failed to insert value to pmu_map[0] > ERROR: Apply config to BPF failed: Invalid option for map, add -v to see > detail > Opening /sys/kernel/debug/tracing//kprobe_events write= > ... > > Looks like perf sets attr.inherit for cycles? I'll look into this problem. yes. that's perf default. How did it even work before?! I was testing with your samples/bpf/tracex6 that sets inherit to zero.