From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932770AbcFORoA (ORCPT ); Wed, 15 Jun 2016 13:44:00 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38157 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932121AbcFORn4 (ORCPT ); Wed, 15 Jun 2016 13:43:56 -0400 Date: Wed, 15 Jun 2016 19:43:48 +0200 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , linux-kernel@vger.kernel.org, x86@kernel.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-arch@vger.kernel.org, Davidlohr Bueso , Jason Low , Dave Chinner , Scott J Norton , Douglas Hatch Subject: Re: [RFC PATCH-tip v2 5/6] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation Message-ID: <20160615174348.GT30921@twins.programming.kicks-ass.net> References: <1465944489-43440-1-git-send-email-Waiman.Long@hpe.com> <1465944489-43440-6-git-send-email-Waiman.Long@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1465944489-43440-6-git-send-email-Waiman.Long@hpe.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 14, 2016 at 06:48:08PM -0400, Waiman Long wrote: > even the reduced maximum of about 16k (32-bit) or 1G (64-bit) should > be more than enough for the foreseeable future. So what happens if I manage to create 16k+ threads on my 32bit kernel and get them all to do mmap() or so at the same time. That doesn't seem too far fetched. Then again, with double that (the current limit) that doesn't seem impossible either.