From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752054AbbGOCXg (ORCPT ); Tue, 14 Jul 2015 22:23:36 -0400 Received: from zeroeth.unpythonic.net ([162.243.242.154]:58019 "EHLO zeroeth.unpythonic.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751769AbbGOCXf (ORCPT ); Tue, 14 Jul 2015 22:23:35 -0400 Date: Tue, 14 Jul 2015 21:23:31 -0500 From: Jeff Epler To: Ken Moffat Cc: linux-kernel@vger.kernel.org Subject: Re: make -jN (n>1) ineffective in 4.2.0-rc on AMD Phenom Message-ID: <20150715022331.GE70510@unpythonic.net> References: <20150714233920.GA15565@milliways> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150714233920.GA15565@milliways> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org GNU Make 4.1 has a problem that causes it to be unable to use the desired level of parallelism. Two people have reported that reverting a commit which changes from fork to vfork "fixes" it. (i'm one of them, unfortunately posting as anonymous in the tracker). Hoewver, if you are also seeing the linux kernel version as relevant to producing the problem, that's quite interesting, and the underlying cause may be different. We reproduced the problem on a range of older kernels, from 3.2 to 3.18. http://savannah.gnu.org/bugs/?44555 Jeff