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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 B1943C432BE for ; Thu, 19 Aug 2021 18:27:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97A3A61042 for ; Thu, 19 Aug 2021 18:27:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234588AbhHSS2J (ORCPT ); Thu, 19 Aug 2021 14:28:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233971AbhHSS2E (ORCPT ); Thu, 19 Aug 2021 14:28:04 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A7A2C061575; Thu, 19 Aug 2021 11:27:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+bTbGbKR1TC3lLaeYOl/sYgM2QGbnXnwBH0Mh0F17/8=; b=dwnz0X/tx54x1HktT+4On+TT9z latNRYxu0+rNhJfDYrdmGkBAEoK1AnNpwjGsZ1DeRptGGLHrrpEcyaS1ktmEWDQcmX/L2leHgCqX4 bbH9hgbcBUt25KNkD3idyXf5xo4ZECBZRG5jhA++GLITSSgR9K18BwvyVDRiY+vQ77Ygv+7UKPiJW s/1Yljo76fi0RXFMl1mw8ImBKRQrMqcgzFIaUQGChBdO7Qlwj3WMC52bnbVLzgmDMW16pXXH2PKqS b5jUIyHThWO14FWV3SUQcjYmwYF/DgAcjb02UeZQyeWJZPSc1KbWur0bvdiP6vyr6/Pc5+wJF9BPb R7wd1eHA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mGml6-00BAqC-1B; Thu, 19 Aug 2021 18:27:20 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 675863012AD; Thu, 19 Aug 2021 20:27:19 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4D012202317D2; Thu, 19 Aug 2021 20:27:19 +0200 (CEST) Date: Thu, 19 Aug 2021 20:27:19 +0200 From: Peter Zijlstra To: Song Liu Cc: "open list:BPF (Safe dynamic programs and tools)" , "linux-kernel@vger.kernel.org" , "acme@kernel.org" , "mingo@redhat.com" , Kernel Team , Kan Liang , Like Xu , Alexey Budankov Subject: Re: [RFC] bpf: lbr: enable reading LBR from tracing bpf programs Message-ID: References: <20210818012937.2522409-1-songliubraving@fb.com> <962EDD5A-1B35-4C7F-A0A1-3EBC32EE63AB@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 19, 2021 at 06:22:07PM +0000, Song Liu wrote: > > And if we're going to be adding new pmu::methods then I figure one that > > does the whole sample state might be more useful. > > What do you mean by "whole sample state"? To integrate with exiting > perf_sample_data, like perf_output_sample()? Yeah, the PMI can/does set more than data->br_stack, but I'm now thinking that without an actual PMI, much of that will not be possible. br_stack is special here. Oh well, carry on I suppose.