Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:13344 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753545Ab3CFSSC (ORCPT ); Wed, 6 Mar 2013 13:18:02 -0500 Date: Wed, 6 Mar 2013 19:16:08 +0100 From: Oleg Nesterov To: Tejun Heo Cc: Jeff Layton , "Myklebust, Trond" , Mandeep Singh Baines , Ming Lei , "J. Bruce Fields" , Linux Kernel Mailing List , "linux-nfs@vger.kernel.org" , "Rafael J. Wysocki" , Andrew Morton , Ingo Molnar , Al Viro Subject: Re: LOCKDEP: 3.9-rc1: mount.nfs/4272 still has locks held! Message-ID: <20130306181608.GA18687@redhat.com> References: <20130304205307.GA13527@redhat.com> <4FA345DA4F4AE44899BD2B03EEEC2FA9286AEEB0@sacexcmbx05-prd.hq.netapp.com> <20130305082308.6607d4db@tlielax.poochiereds.net> <20130305174648.GF12795@htj.dyndns.org> <20130305174954.GG12795@htj.dyndns.org> <20130305140312.243cb094@tlielax.poochiereds.net> <20130305190923.GI12795@htj.dyndns.org> <20130305183941.19ff39ce@tlielax.poochiereds.net> <20130305234700.GE1227@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20130305234700.GE1227@htj.dyndns.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On 03/05, Tejun Heo wrote: > > Oleg, are you still opposed to the idea of making freezer share trap > points with ptrace? My memory can fool me, but iirc I wasn't actually opposed... I guess you mean the previous discussion about vfork/ptrace/etc which I forgot completely. But I can recall the main problem with your idea (with me): I simply wasn't able to understand it ;) Likewise, I can't really understand the ideas discussed in this thread. At least when it come to this particular problem, rpc_wait_bit_killable() is not interruptible... And how SIGFREEZE can help? If we want to interrupt the sleeps in NFS/RPC layer we can simply add TASK_WAKEFREEZE (can be used with TASK_KILLABLE) and change freeze_task() to do signal_wake_up_state(TASK_WAKEFREEZE). But if we can do this, then it should be possible so simply make these sleeps TASK_INTERRUPTIBLE ? But it seems that we can't just because we can't always restart, so I am totally confused. Oleg.