Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268722AbUILNko (ORCPT ); Sun, 12 Sep 2004 09:40:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268723AbUILNko (ORCPT ); Sun, 12 Sep 2004 09:40:44 -0400 Received: from mx1.elte.hu ([157.181.1.137]:28338 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S268722AbUILNk2 (ORCPT ); Sun, 12 Sep 2004 09:40:28 -0400 Date: Sun, 12 Sep 2004 15:41:37 +0200 From: Ingo Molnar To: Arjan van de Ven Cc: Anton Blanchard , linux-kernel@vger.kernel.org, viro@parcelfarce.linux.theplanet.co.uk, wli@holomorphy.com Subject: Re: /proc/sys/kernel/pid_max issues Message-ID: <20040912134137.GA20136@elte.hu> References: <20040912085609.GK32755@krispykreme> <1094991480.2626.0.camel@laptop.fenrus.com> <20040912122959.GN25741@krispykreme> <20040912124420.GA29587@devserv.devel.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040912124420.GA29587@devserv.devel.redhat.com> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 981 Lines: 29 * Arjan van de Ven wrote: > On Sun, Sep 12, 2004 at 10:30:00PM +1000, Anton Blanchard wrote: > > > > Hmm can you point the 16bit counter out? I can create 1 million NPTL > > threads on ppc64 easily, so why not? > > /* > * the semaphore definition > */ > struct rw_semaphore { > /* XXX this should be able to be an atomic_t -- paulus */ > signed int count; > #define RWSEM_UNLOCKED_VALUE 0x00000000 > #define RWSEM_ACTIVE_BIAS 0x00000001 > #define RWSEM_ACTIVE_MASK 0x0000ffff > > that counter is split in 2 16 bit entities.... the generic semaphore code can handle up to ~2^31 waiters. I once tried it on x86, it seems to work fine. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/