From owner-freebsd-current@FreeBSD.ORG Sun May 30 14:30:39 2010 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0CE6D1065686; Sun, 30 May 2010 14:30:39 +0000 (UTC) (envelope-from amdmi3@amdmi3.ru) Received: from smtp.timeweb.ru (smtp.timeweb.ru [92.53.116.15]) by mx1.freebsd.org (Postfix) with ESMTP id BA25C8FC08; Sun, 30 May 2010 14:30:38 +0000 (UTC) Received: from [213.148.20.85] (helo=hive.panopticon) by smtp.timeweb.ru with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.71) (envelope-from ) id 1OIjX9-0003AV-RD; Sun, 30 May 2010 18:30:36 +0400 Received: from hades.panopticon (hades.panopticon [192.168.0.32]) by hive.panopticon (Postfix) with ESMTP id 1618CB84D; Sun, 30 May 2010 18:30:35 +0400 (MSD) Received: by hades.panopticon (Postfix, from userid 1000) id 032DCB833; Sun, 30 May 2010 18:30:35 +0400 (MSD) Date: Sun, 30 May 2010 18:30:35 +0400 From: Dmitry Marakasov To: freebsd-stable@FreeBSD.org, freebsd-current@FreeBSD.org Message-ID: <20100530143034.GH43302@hades.panopticon> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Cc: Subject: need better POSIX semaphore support X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 May 2010 14:30:39 -0000 Hi! Not long ago, POSIX semaphores support was enabled by default as it's becoming more widely used, by e.g. firefox. However, the support for these is still incomplete: we only have systemwide limit of 30 semaphores, and that doesn't seem to be configurable neither online with sysctl, nor at boottime from loader.conf. I only was able to raise semaphore count by changing SEM_MAX in kernel sources. The real appliaction which needs more semaphores is lightspark (graphics/lightspark-devel) flash plugin - it uses ~40 sems for simple clips and ~250 for something like youtube videos. Until there more apps that require proper semaphore support, I guess we need to improve it asap. Given the amount of memory used by ksem, the least can be done is SEM_MAX bumped up to 5120 or so for non-embedded kernels. 5120 semaphores require just 644k of kernel memory (judging by vmstat), and is "ought to be enough for anybody". Another good thing would be to make it configurable at boot-time or even better in runtime. -- Dmitry Marakasov . 55B5 0596 FF1E 8D84 5F56 9510 D35A 80DD F9D2 F77D amdmi3@amdmi3.ru ..: jabber: amdmi3@jabber.ru http://www.amdmi3.ru