From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B92E4C76196 for ; Fri, 7 Apr 2023 20:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229822AbjDGUbS (ORCPT ); Fri, 7 Apr 2023 16:31:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229848AbjDGUbR (ORCPT ); Fri, 7 Apr 2023 16:31:17 -0400 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CB3E7A83 for ; Fri, 7 Apr 2023 13:31:16 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id j1so3814098wrb.0 for ; Fri, 07 Apr 2023 13:31:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680899474; x=1683491474; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=0qibfGmguJ4UfrBa5vhdJz7TU0Ic3a95y1BNUi4NdCA=; b=APQmZXOFWZ5EEcZfHQqOhAvX+iKXBO4pPSDNvV86nkBTQWokDuApno+EbjCQyZ5m8d lOi/dw/nVQwCwu35Z2nRs3kq3qbapXE6zgTQvX2t2mD8r5gJvFBOdjck0oMtOQE3Hamf b8FWrjeZ0hhZLNt0WmEqaXf9+uLX+ID+HpJhvWHadH4Z85l0rCMfqV+ilHM6MOm3GXvr REsEOGcqCloJkgw/VJ3A4HCBJ3+KmJpukKMSqAQE9M+PWrVm/p/ZwOyMfVgodCIF2B12 GUsThvOttv7bqfLylxOL2Rc9i65jSSeM82HJbWF6KXhG0hhyHHfEk2qwo39HfMGsXrD9 fwYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680899474; x=1683491474; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=0qibfGmguJ4UfrBa5vhdJz7TU0Ic3a95y1BNUi4NdCA=; b=32GZojnmEe3KNsWGO8TSMdes3yKVdrdzMyUYLs7d7Q5hmTSe2sHvPqI0/n1zrB3Gk1 A8/87HVEl1Wd0OQenlMBteayfeAU1UIxIBs8R+Si9QWgCbVbMfs4XAp0YJr3qxpBnYSg 5NEVJ3pKpU5yBEvQavNYB13zxfloCvWsZpO85XEY/oGqYIOlXJbLZ+t2DbzNBUpTssIp smdPBSxgWCYIcNsGFiO1q9xUpZN+hNQWZOufMpY4uz5JsYczzT399CrpH+x6tPNEXMXl IYju1MO/vM4iN1jgTMIqu7BDyZVgHYFTO7qmKgXctNtOrrcIE5K0m43vPzZF4fjGctBw 9yVQ== X-Gm-Message-State: AAQBX9c5rN8NRpt/y918CIqzJJ2jcOyxCldIgUs279zGAYNQf4gFXGu8 ynNiWV3oag4gj5pH3igygQaJoLHGtqd5H+JNqkk= X-Google-Smtp-Source: AKy350ZPXtkQEkwkuCizMe3J18x/9aJksTnPXroCHmzxor1W7GuBjbr592/0Q05TOyYAweLEaXcfZQ== X-Received: by 2002:adf:e882:0:b0:2e5:87cc:54b3 with SMTP id d2-20020adfe882000000b002e587cc54b3mr2112344wrm.54.1680899474359; Fri, 07 Apr 2023 13:31:14 -0700 (PDT) Received: from krava (cpc137424-wilm3-2-0-cust276.1-4.cable.virginm.net. [82.23.5.21]) by smtp.gmail.com with ESMTPSA id m3-20020adfdc43000000b002c5691f13eesm5324450wrj.50.2023.04.07.13.31.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Apr 2023 13:31:13 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Fri, 7 Apr 2023 21:31:11 +0100 To: Song Liu Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kernel-team@meta.com Subject: Re: [PATCH bpf-next] selftests/bpf: Use PERF_COUNT_HW_CPU_CYCLES event for get_branch_snapshot Message-ID: References: <20230407190130.2093736-1-song@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230407190130.2093736-1-song@kernel.org> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Apr 07, 2023 at 12:01:30PM -0700, Song Liu wrote: > perf_event with type=PERF_TYPE_RAW and config=0x1b00 turned out to be not > reliable in ensuring LBR is active. Thus, test_progs:get_branch_snapshot is > not reliable in some systems. Replace it with PERF_COUNT_HW_CPU_CYCLES > event, which gives more consistent results. > > Signed-off-by: Song Liu Acked-by: Jiri Olsa jirka > --- > tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c > index 3948da12a528..0394a1156d99 100644 > --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c > +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c > @@ -37,8 +37,8 @@ static int create_perf_events(void) > > /* create perf event */ > attr.size = sizeof(attr); > - attr.type = PERF_TYPE_RAW; > - attr.config = 0x1b00; > + attr.type = PERF_TYPE_HARDWARE; > + attr.config = PERF_COUNT_HW_CPU_CYCLES; > attr.sample_type = PERF_SAMPLE_BRANCH_STACK; > attr.branch_sample_type = PERF_SAMPLE_BRANCH_KERNEL | > PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY; > -- > 2.34.1 >