Return-Path: linux-nfs-owner@vger.kernel.org Received: from xes-mad.com ([216.165.139.218]:30510 "EHLO xes-mad.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751015AbaCFSfT (ORCPT ); Thu, 6 Mar 2014 13:35:19 -0500 Date: Thu, 6 Mar 2014 12:35:06 -0600 (CST) From: Andrew Martin To: Jim Rees Cc: bhawley@luminex.com, NeilBrown , linux-nfs-owner@vger.kernel.org, linux-nfs@vger.kernel.org Message-ID: <1397912955.101159.1394130906695.JavaMail.zimbra@xes-inc.com> In-Reply-To: <20140306173632.GA18545@umich.edu> References: <1696396609.119284.1394040541217.JavaMail.zimbra@xes-inc.com> <1853694865.210849.1394082223818.JavaMail.zimbra@xes-inc.com> <20140306163721.0edfb498@notabene.brown> <1709792528-1394084840-cardhu_decombobulator_blackberry.rim.net-1367662481-@b5.c4.bise6.blackberry> <764210708.28409.1394119821635.JavaMail.zimbra@xes-inc.com> <20140306162208.GA18207@umich.edu> <1094203678.52139.1394124222574.JavaMail.zimbra@xes-inc.com> <20140306173632.GA18545@umich.edu> Subject: Re: Optimal NFS mount options to safely allow interrupts and timeouts on newer kernels MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: > From: "Jim Rees" > Why would a bunch of blocked apaches cause high load and reboot? What I believe happens is the apache child processes go to serve these requests and then block in uninterruptable sleep. Thus, there are fewer and fewer child processes to handle new incoming requests. Eventually, apache would normally kill said children (e.g after a child handles a certain number of requests), but it cannot kill them because they are in uninterruptable sleep. As more and more incoming requests are queued (and fewer and fewer child processes are available to serve the requests), the load climbs.