This message generated a parse failure. Raw output follows here. Please use 'back' to navigate. From devnull@lkml.org Fri Apr 26 19:21:23 2024 >From mailfetcher Wed Oct 17 13:08:02 2018 Envelope-to: lkml@grols.ch Delivery-date: Wed, 17 Oct 2018 13:07:11 +0200 Received: from stout.grols.ch [195.201.141.146] by 72459556e3a9 with IMAP (fetchmail-6.3.26) for (single-drop); Wed, 17 Oct 2018 13:08:02 +0200 (CEST) Received: from vger.kernel.org ([209.132.180.67]) by stout.grols.ch with esmtp (Exim 4.89) (envelope-from ) id 1gCjfT-0003W0-Eg for lkml@grols.ch; Wed, 17 Oct 2018 13:07:11 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727016AbeJQTCU (ORCPT ); Wed, 17 Oct 2018 15:02:20 -0400 Received: from merlin.infradead.org ([205.233.59.134]:48854 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727000AbeJQTCU (ORCPT ); Wed, 17 Oct 2018 15:02:20 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gCjfB-0000p6-Nm; Wed, 17 Oct 2018 11:06:54 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1B73520298568; Wed, 17 Oct 2018 13:06:51 +0200 (CEST) Date: Wed, 17 Oct 2018 13:06:51 +0200 From: Peter Zijlstra To: Song Liu Cc: Alexey Budankov , Ingo Molnar , lkml , "acme@kernel.org" , Alexander Shishkin , J Subject: Re: [RFC][PATCH] perf: Rewrite core context handling Message-Id: <20181017110651.GI3121@hirez.programming.kicks-ass.net> References: <20181010104559.GO5728@hirez.programming.kicks-ass.net> <3a738a08-2295-a4e9-dce7-a3e2b2ad794e@linux.intel.com> <20181015083448.GN9867@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-Id: X-Mailing-List: linux-kernel@vger.kernel.org Received-SPF: none client-ip=209.132.180.67; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org X-Spam-Score: -2.3 X-Spam-Score-Bar: -- X-Spam-Action: no action X-Spam-Report: Action: no action Symbol: ARC_NA(0.00) Symbol: TO_DN_EQ_ADDR_SOME(0.00) Symbol: RCVD_COUNT_FIVE(0.00) Symbol: RCVD_VIA_SMTP_AUTH(0.00) Symbol: FROM_HAS_DN(0.00) Symbol: TO_DN_SOME(0.00) Symbol: R_DKIM_REJECT(1.00) Symbol: PRECEDENCE_BULK(0.00) Symbol: MI On Tue, Oct 16, 2018 at 06:28:10PM +0000, Song Liu wrote: > > How about this:=20 > >=20 > > 1. Keep multiple perf_cpu_context per CPU, just like before this patch.= =20 > >=20 > > 2. For perf_event_context, add PMU as an order for the RB tree.=20 > >=20 > > 3. (hw) pmu->perf_cpu_context->ctx only has events for this PMU (and sw= =20 > > events moved to this context). > >=20 > > 4. task->perf_event_ctxp has events for all PMUs.=20 > >=20 > > With this path, we keep the existing perf_cpu_context/perf_event_context > > logic as-is, which I think is simp=10ler than the new logic (with extra > > *_pmu_context). And it should also solve the problem.=20 > >=20 > > Does this make sense? If this doesn't look too broken, I am happy to > > draft RFC for it.=20 > >=20 >=20 > I am not sure whether you missed this one, or found it totally insane.=20 > Could you please share your comments on it? My gut feeling is that this= =20 > would be a simpler patch to solve the problem (two hw PMUs). (It might=20 > be less efficient though).=20 Ah, sorry, somehow this email got lost. That makes task and cpu contexts wildly different, which will complicate matters I feel.