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 49705ECAAD8 for ; Thu, 22 Sep 2022 19:23:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230211AbiIVTXN (ORCPT ); Thu, 22 Sep 2022 15:23:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229598AbiIVTXM (ORCPT ); Thu, 22 Sep 2022 15:23:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 894F2286D6; Thu, 22 Sep 2022 12:23:11 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1EE9C61175; Thu, 22 Sep 2022 19:23:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52694C433D7; Thu, 22 Sep 2022 19:23:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663874590; bh=2DZjj8mS7EZ9M/LXHnntgYzTasGSbm7dQDwq3kbKrRU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r4c2Z+6Trx3SV1wFpJqn4BFOBW6BC8w7thIgfQWX74LAcI+V+O0N/WRFFUtd+Ihvi iLZ1wEggUF41RDsoday1TMULHLMRXkXw9122nsBxKAtPkt1RQLOzEWmmn8BRasg1CR E0NPWAYW29BrVPmUsJtdRzUG9B+8EtGqvT4xUet+SYLv+z/kONZ4iBxQQlbJbGDCWD Ws9HurS6Saaf/MjkBzf7ndLtNbfylsFF3wRgcLTWUrDoWhrZzhz9u2K4C4QOpIWak2 YM7WsbMA0GjeUfgiIoUO0ZSSA58qUTDN/xok/YmcH1MQhk2VLMN9/S/CAzxX/Hk93v vLTOG1egpTOtA== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 0B3A6403B0; Thu, 22 Sep 2022 20:23:08 +0100 (IST) Date: Thu, 22 Sep 2022 20:23:08 +0100 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Jiri Olsa , Ingo Molnar , Peter Zijlstra , LKML , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Song Liu , bpf@vger.kernel.org Subject: Re: [PATCH v2] perf tools: Get a perf cgroup more portably in BPF Message-ID: References: <20220922044023.718774-1-namhyung@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220922044023.718774-1-namhyung@kernel.org> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Em Wed, Sep 21, 2022 at 09:40:23PM -0700, Namhyung Kim escreveu: > The perf_event_cgrp_id can be different on other configurations. > To be more portable as CO-RE, it needs to get the cgroup subsys id > using the bpf_core_enum_value() helper. > > Suggested-by: Ian Rogers > Signed-off-by: Namhyung Kim Applying, Ian, can I have your Reviewed-by? - Arnaldo > --- > v2 changes) > * fix off_cpu.bpf.c too > * get perf_subsys_id only once > > tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 6 +++++- > tools/perf/util/bpf_skel/off_cpu.bpf.c | 12 ++++++++---- > 2 files changed, 13 insertions(+), 5 deletions(-) > > diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > index 292c430768b5..9223e4b87fe9 100644 > --- a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > +++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > @@ -48,6 +48,7 @@ const volatile __u32 num_cpus = 1; > > int enabled = 0; > int use_cgroup_v2 = 0; > +int perf_subsys_id = -1; > > static inline int get_cgroup_v1_idx(__u32 *cgrps, int size) > { > @@ -58,7 +59,10 @@ static inline int get_cgroup_v1_idx(__u32 *cgrps, int size) > int level; > int cnt; > > - cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_event_cgrp_id], cgroup); > + if (perf_subsys_id == -1) > + perf_subsys_id = bpf_core_enum_value(enum cgroup_subsys_id, perf_event_cgrp_id); > + > + cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_subsys_id], cgroup); > level = BPF_CORE_READ(cgrp, level); > > for (cnt = 0; i < MAX_LEVELS; i++) { > diff --git a/tools/perf/util/bpf_skel/off_cpu.bpf.c b/tools/perf/util/bpf_skel/off_cpu.bpf.c > index c4ba2bcf179f..e917ef7b8875 100644 > --- a/tools/perf/util/bpf_skel/off_cpu.bpf.c > +++ b/tools/perf/util/bpf_skel/off_cpu.bpf.c > @@ -94,6 +94,8 @@ const volatile bool has_prev_state = false; > const volatile bool needs_cgroup = false; > const volatile bool uses_cgroup_v1 = false; > > +int perf_subsys_id = -1; > + > /* > * Old kernel used to call it task_struct->state and now it's '__state'. > * Use BPF CO-RE "ignored suffix rule" to deal with it like below: > @@ -119,11 +121,13 @@ static inline __u64 get_cgroup_id(struct task_struct *t) > { > struct cgroup *cgrp; > > - if (uses_cgroup_v1) > - cgrp = BPF_CORE_READ(t, cgroups, subsys[perf_event_cgrp_id], cgroup); > - else > - cgrp = BPF_CORE_READ(t, cgroups, dfl_cgrp); > + if (!uses_cgroup_v1) > + return BPF_CORE_READ(t, cgroups, dfl_cgrp, kn, id); > + > + if (perf_subsys_id == -1) > + perf_subsys_id = bpf_core_enum_value(enum cgroup_subsys_id, perf_event_cgrp_id); > > + cgrp = BPF_CORE_READ(t, cgroups, subsys[perf_subsys_id], cgroup); > return BPF_CORE_READ(cgrp, kn, id); > } > > -- > 2.37.3.968.ga6b4b080e4-goog -- - Arnaldo