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=-4.0 required=3.0 tests=BAYES_00, 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 42363C433E0 for ; Tue, 11 Aug 2020 18:04:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15B7420656 for ; Tue, 11 Aug 2020 18:04:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726134AbgHKSED (ORCPT ); Tue, 11 Aug 2020 14:04:03 -0400 Received: from mga02.intel.com ([134.134.136.20]:61977 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725889AbgHKSED (ORCPT ); Tue, 11 Aug 2020 14:04:03 -0400 IronPort-SDR: BFyJdXhqB42qJpl5EXNCbyMbdZeFszE74sE0Vt4cr15g+OXKNz9DktmvwmtlPWdcIADRwI33tY GVUqciyS/IYA== X-IronPort-AV: E=McAfee;i="6000,8403,9710"; a="141644208" X-IronPort-AV: E=Sophos;i="5.76,301,1592895600"; d="scan'208";a="141644208" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2020 11:03:34 -0700 IronPort-SDR: zVv4eU1IJ+Px03kish9Dant3Vn8Yba/ZAH97DTiKTwFjiMbjLxVyTqnESBg65BYgStzTK+Y8vI 6/c0SX/PsRtw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,301,1592895600"; d="scan'208";a="324832517" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.21]) by orsmga008.jf.intel.com with ESMTP; 11 Aug 2020 11:03:34 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id AA91F301CB0; Tue, 11 Aug 2020 11:03:34 -0700 (PDT) Date: Tue, 11 Aug 2020 11:03:34 -0700 From: Andi Kleen To: David Laight Cc: Peter Zijlstra , Alexander Shishkin , Arnaldo Carvalho de Melo , Ingo Molnar , "linux-kernel@vger.kernel.org" , Jiri Olsa , "alexey.budankov@linux.intel.com" , "adrian.hunter@intel.com" Subject: Re: [PATCH 1/2] perf: Add closing sibling events' file descriptors Message-ID: <20200811180334.GH1448395@tassilo.jf.intel.com> References: <20200708151635.81239-1-alexander.shishkin@linux.intel.com> <20200708151635.81239-2-alexander.shishkin@linux.intel.com> <20200806083530.GV2674@hirez.programming.kicks-ass.net> <20200806153205.GA1448395@tassilo.jf.intel.com> <875z9q1u3g.fsf@ashishki-desk.ger.corp.intel.com> <20200810144518.GB1448395@tassilo.jf.intel.com> <20200810203632.GF3982@worktop.programming.kicks-ass.net> <20200811142955.GC1448395@tassilo.jf.intel.com> <9ff26c5231954e65bbd4873d54ebd727@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9ff26c5231954e65bbd4873d54ebd727@AcuMS.aculab.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 11, 2020 at 02:47:03PM +0000, David Laight wrote: > From: Andi Kleen > > On Mon, Aug 10, 2020 at 10:36:32PM +0200, Peter Zijlstra wrote: > > > On Mon, Aug 10, 2020 at 07:45:18AM -0700, Andi Kleen wrote: > > > > > > > Unfortunately we're kind of stuck with the old NFILE=1024 default > > > > even though it makes little sense on modern servers. > > > > > > Why can't that be changed? It seems to me all of userspace changes all > > > the time; heck that system-doofus thing flushed 20+ years of sysadmin > > > experience down the drain, just cause. Why can't we up a file limit? > > > > We could try, but I believe it's hard coded in various places outside > > the kernel. > > The place it really bites is select(). > Although the kernel supports large bitmaps glibc doesn't. > The random bit overwrites are a PITA to debug. Good point. I remember I asked for a simple define to increase like glibc5 had, but they still didn't implement that. -Andi