Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp5133106yba; Wed, 10 Apr 2019 12:05:27 -0700 (PDT) X-Google-Smtp-Source: APXvYqzgV33Y7c/H8u130s05RVbe4pp/IFk/WP/jEr9rz5HAWQMWhuBCBddbvjs2YMvP8to2q+5Y X-Received: by 2002:a63:c84c:: with SMTP id l12mr42744812pgi.287.1554923127755; Wed, 10 Apr 2019 12:05:27 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1554923127; cv=none; d=google.com; s=arc-20160816; b=JvfCajydLPkTX94E7YspbL1ZZWfb9cT4rLKlbzX8nyUA/hxryApkp6R9EaCUnJT9UP USC9ttoKGY4QlUDxMMvVhotHNij4gsjQ1lDFQjKWh7EBLBX1Dzb8FtcbVv9YDNvfSPK+ tFvNW1K3E+2cJOXoYd5JxsdLYI+Pjx0/DAADwQtV992hoG5Qoi+23OiX25eJ8G2GAxMh mQOnC4BuhpQNrm8OZRrykXCwnHnOiyXUGNrWnYKRxH7NuYJrm4ZSDQ60ts4xpzlBJNpJ nqLkEThqZBrgzki7TP23DM33M8eyh1TSyG7TKMZiVPJVKLMgrQ4bii9bQGn8uwOeK+C8 gjgQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=gXVNYEga54rb82N1xWNq23KKEOyzn8Uaq+dPikPBLKo=; b=KK6WUc7VGVDrjj8WqceM35sivgETPzB8moR85zLMBVhDIneMfFvVwzlPvHGYgOv3Vj ZCPUZsZaPYqZjpiZ2EX2TdIoYzJ0X7f0goeD+vQwKDEwt8Hig1uuOlQ6FV579fco0zcx awRso/7B0pVg8Kt7BlkLAq0H2QQjylTFHPDg8iS6EVwIHdZy40P4MLUOyGOnRmC8d4ep 0qrChe3Fbuh4or/Ubcq547chChwE6uw9CVS8dimf+dc00/qsY012j4jMMEIHEiYxtvD1 bKhoBDaKa3FNEWM2UyRgpsXOziUmCIMM6qC6ncWG8tSMPrsrSlv+svCDoeXlgICFuLgq XB+A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id m79si33831443pfi.81.2019.04.10.12.05.11; Wed, 10 Apr 2019 12:05:27 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729445AbfDJRbv (ORCPT + 99 others); Wed, 10 Apr 2019 13:31:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:56632 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726556AbfDJRbv (ORCPT ); Wed, 10 Apr 2019 13:31:51 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id EBB62AC5C; Wed, 10 Apr 2019 17:31:49 +0000 (UTC) Date: Wed, 10 Apr 2019 10:31:42 -0700 From: Davidlohr Bueso To: Waiman Long Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner , linux-kernel@vger.kernel.org, x86@kernel.org, Linus Torvalds , Tim Chen Subject: Re: [PATCH-tip v2 06/12] locking/rwsem: Wake up almost all readers in wait queue Message-ID: <20190410173142.dt5uldtgt4brhtjj@linux-r8p5> References: <20190405192115.17416-1-longman@redhat.com> <20190405192115.17416-7-longman@redhat.com> <20190410165013.njy5bg32pxq6syyr@linux-r8p5> <114e3bc3-3b66-4a50-d422-6a477d85fa72@redhat.com> <20190410172254.ivgcgehjhqgwjtda@linux-r8p5> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20190410172254.ivgcgehjhqgwjtda@linux-r8p5> User-Agent: NeoMutt/20180323 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 10 Apr 2019, Bueso wrote: >On Wed, 10 Apr 2019, Waiman Long wrote: >>2) I want to avoid the extreme case that there are more than 32k readers >>in the wait queue and make the count overflow. > >But in this case the readers are already on the queue. Never mind this. But the limit could still be enlarged just to prevent overflows in the case where there are only readers.