Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932568AbbLQUeo (ORCPT ); Thu, 17 Dec 2015 15:34:44 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:56727 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932139AbbLQUem (ORCPT ); Thu, 17 Dec 2015 15:34:42 -0500 Date: Thu, 17 Dec 2015 15:34:41 -0500 (EST) Message-Id: <20151217.153441.1336096182651045503.davem@davemloft.net> To: rweikusat@mobileactivedefense.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] af_unix: Revert 'lock_interruptible' in stream receive code From: David Miller In-Reply-To: <877fke6tqi.fsf@doppelsaurus.mobileactivedefense.com> References: <877fke6tqi.fsf@doppelsaurus.mobileactivedefense.com> X-Mailer: Mew version 6.6 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 17 Dec 2015 12:34:42 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1182 Lines: 23 From: Rainer Weikusat Date: Wed, 16 Dec 2015 20:09:25 +0000 > With b3ca9b02b00704053a38bfe4c31dbbb9c13595d0, the AF_UNIX SOCK_STREAM > receive code was changed from using mutex_lock(&u->readlock) to > mutex_lock_interruptible(&u->readlock) to prevent signals from being > delayed for an indefinite time if a thread sleeping on the mutex > happened to be selected for handling the signal. But this was never a > problem with the stream receive code (as opposed to its datagram > counterpart) as that never went to sleep waiting for new messages with the > mutex held and thus, wouldn't cause secondary readers to block on the > mutex waiting for the sleeping primary reader. As the interruptible > locking makes the code more complicated in exchange for no benefit, > change it back to using mutex_lock. > > Signed-off-by: Rainer Weikusat Applied, thanks Rainer. -- 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/