Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754522AbYG2A1i (ORCPT ); Mon, 28 Jul 2008 20:27:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752144AbYG2A13 (ORCPT ); Mon, 28 Jul 2008 20:27:29 -0400 Received: from smtp-out.google.com ([216.239.33.17]:58098 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752298AbYG2A12 (ORCPT ); Mon, 28 Jul 2008 20:27:28 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=NMsbSCyGkuSmTo7KW3eRXJXftoBQFbnXilbuhlIZk5sU80vUblgb8wBYNH1wfXDyA UmF36QlXJ3F6p1IcA3PSw== Message-ID: <6599ad830807281727r63a57a1g11972c5395828aae@mail.gmail.com> Date: Mon, 28 Jul 2008 17:27:15 -0700 From: "Paul Menage" To: "Rusty Russell" Subject: Re: [PATCH] Introduce down_try() so we can move away from down_trylock() Cc: "Linus Torvalds" , linux-kernel@vger.kernel.org, "Matthew Wilcox" , "Randy.Dunlap" , "Andrew Morton" , "Christoph Hellwig" In-Reply-To: <200807291015.02865.rusty@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200807291015.02865.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1640 Lines: 39 On Mon, Jul 28, 2008 at 5:15 PM, Rusty Russell wrote: > I planned on removing the much-disliked down_trylock() (with its > backwards return codes) in 2.6.27, but it's creating something of a > logjam with other patches in -mm and linux-next. > > Andrew suggested introducing "down_try" as a wrapper now, to make > the transition easier. Linus, please apply. > > Signed-off-by: Rusty Russell > Cc: Andrew Morton > Cc: Christoph Hellwig > Cc: Matthew Wilcox > Cc: Stephen Rothwell > --- > include/linux/semaphore.h | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff -r 92664ae4130b include/linux/semaphore.h > --- a/include/linux/semaphore.h Wed May 21 14:54:40 2008 +1000 > +++ b/include/linux/semaphore.h Wed May 21 15:07:31 2008 +1000 > @@ -48,4 +48,18 @@ extern int __must_check down_timeout(str > extern int __must_check down_timeout(struct semaphore *sem, long jiffies); > extern void up(struct semaphore *sem); > > +/** > + * down_try - try to down a semaphore, but don't block > + * @sem: the semaphore > + * > + * This is equivalent to down_trylock(), but has the same return codes as > + * spin_trylock and mutex_trylock: 1 if semaphore acquired, 0 if not. Is there a reason to avoid using a return type of "bool" for this? Paul -- 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/