From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id D60BCB7079 for ; Wed, 19 Aug 2009 19:41:23 +1000 (EST) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 856B5DDD04 for ; Wed, 19 Aug 2009 19:41:23 +1000 (EST) Subject: Re: spin_is_locked() broken for uniprocessor? From: Peter Zijlstra To: David Howells In-Reply-To: <7099.1250674686@redhat.com> References: <7099.1250674686@redhat.com> Content-Type: text/plain Date: Wed, 19 Aug 2009 11:41:10 +0200 Message-Id: <1250674870.7583.334.camel@twins> Mime-Version: 1.0 Cc: Steven Rostedt , Linux-Kernel List , linuxppc-dev list , Thomas Gleixner , Ingo Molnar List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2009-08-19 at 10:38 +0100, David Howells wrote: > Thomas Gleixner wrote: > > > > which implies to me that spin_is_locked() will always return false. Is this > > > expected behavior. > > > > That's wrong. spin_is_locked should always return true on UP. > > Surely it's not that simple? Maybe spin_is_lock() should be undefined on UP. #define spin_is_locked(l) panic() should sort things out quickly ;-)