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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE842C43381 for ; Sun, 17 Feb 2019 23:06:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 979A521773 for ; Sun, 17 Feb 2019 23:06:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727547AbfBQXGB (ORCPT ); Sun, 17 Feb 2019 18:06:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50380 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727250AbfBQXGB (ORCPT ); Sun, 17 Feb 2019 18:06:01 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1DFBC80F81; Sun, 17 Feb 2019 23:06:01 +0000 (UTC) Received: from krava (ovpn-204-33.brq.redhat.com [10.40.204.33]) by smtp.corp.redhat.com (Postfix) with SMTP id 94057608C6; Sun, 17 Feb 2019 23:05:58 +0000 (UTC) Date: Mon, 18 Feb 2019 00:05:57 +0100 From: Jiri Olsa To: Song Liu Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, kernel-team@fb.com, peterz@infradead.org, acme@redhat.com, jolsa@kernel.org, namhyung@kernel.org Subject: Re: [PATCH v3 perf,bpf 11/11] perf, bpf: save information about short living bpf programs Message-ID: <20190217230557.GF7443@krava> References: <20190215215354.3114006-1-songliubraving@fb.com> <20190215215354.3114006-12-songliubraving@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190215215354.3114006-12-songliubraving@fb.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Sun, 17 Feb 2019 23:06:01 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Feb 15, 2019 at 01:53:54PM -0800, Song Liu wrote: > To annotate bpf programs in perf, it is necessary to save information in > bpf_prog_info and btf. For short living bpf program, it is necessary to > save these information before it is unloaded. > > This patch saves these information in a separate thread. This thread > creates its own evlist, that only tracks bpf events. This evlists uses > ring buffer with very low watermark for lower latency. When bpf load > events are received, this thread tries to gather information via sys_bpf > and save it in perf_env. could we make this a generic? like havving support to create a thread that would process sideband evets? itcould be used for the that buildid stuff and for things like getting full command lines from comm events and such jirka