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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 ADF9FC4CC60 for ; Thu, 6 Aug 2020 11:05:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A60B423135 for ; Thu, 6 Aug 2020 11:05:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="so9zJ/Hf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728912AbgHFIh0 (ORCPT ); Thu, 6 Aug 2020 04:37:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726844AbgHFIhZ (ORCPT ); Thu, 6 Aug 2020 04:37:25 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E45F4C061574 for ; Thu, 6 Aug 2020 01:37:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; 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=/s+G2eGqMR8MQPfsMaNKoN8G20XvSbaDF1vueDDt9Ng=; b=so9zJ/Hf9o8jCMTBAOknq8zBhI K63dTVUNOzWsriGmjfplEzJEJCZdrEw0xp4kt8NtrrFAgd2P9OuS2xKrB8QUvE2698EbGeBpJDtlN JYEcolPNktsilJsNLu5AurQ9lshkp4eWfUiPOoCemX+ApTT3bfQKC7OqhCGER0l9n/fvQxTZM9tvy ki7tkEtnXUWQ/NiHCEFWWyOsbYk+Kgw9JLZ3P0QqHQkpotu2Z+YlDmqL3nYfjpS8fqXr+C+tQREB7 5CGasY48zLonbJ8BEWI3CS1dDdCAFxAPMYt60UkZK5j4le/Rts9ehRPIhFimBHaivEY7xrIz0jN20 1IPVUmyg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k3bOq-0002qH-Ml; Thu, 06 Aug 2020 08:37:20 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 009E9300F7A; Thu, 6 Aug 2020 10:37:18 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id E0AEE2B61F1C1; Thu, 6 Aug 2020 10:37:17 +0200 (CEST) Date: Thu, 6 Aug 2020 10:37:17 +0200 From: peterz@infradead.org To: Adrian Hunter , Adrian Hunter , g@hirez.programming.kicks-ass.net Cc: Alexander Shishkin , Arnaldo Carvalho de Melo , Ingo Molnar , linux-kernel@vger.kernel.org, Jiri Olsa , alexey.budankov@linux.intel.com Subject: Re: [PATCH 0/2] perf: Allow closing siblings' file descriptors Message-ID: <20200806083717.GW2674@hirez.programming.kicks-ass.net> References: <20200708151635.81239-1-alexander.shishkin@linux.intel.com> <32ad7700-3d4e-6c20-31c9-8b002fea5cbc@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <32ad7700-3d4e-6c20-31c9-8b002fea5cbc@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 06, 2020 at 09:15:08AM +0300, Adrian Hunter wrote: > On 8/07/20 6:16 pm, Alexander Shishkin wrote: > > Hi guys, > > > > I've been looking at reducing the number of open file descriptors per perf > > session. If we retain one descriptor per event, in a large group they add > > up. At the same time, we're not actually using them for anything after the > > SET_OUTPUT and maybe SET_FILTER ioctls. So, this series is a stab at that. > > I am wondering if instead we should be looking at creating a kernel API that > allows associating a multitude of tracepoints with a single event. Thoughts > anyone? https://lkml.kernel.org/r/1290445737.2072.338.camel@laptop