From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Should suspend plug low-level devices? Date: Wed, 16 Mar 2016 17:05:01 -0700 Message-ID: <20160317000501.GM21104@mtj.duckdns.org> References: <20160316150053.GG6980@mtj.duckdns.org> <20160316163554.GK6980@mtj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-io0-f178.google.com ([209.85.223.178]:34249 "EHLO mail-io0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967159AbcCQAFE (ORCPT ); Wed, 16 Mar 2016 20:05:04 -0400 Received: by mail-io0-f178.google.com with SMTP id m184so79620760iof.1 for ; Wed, 16 Mar 2016 17:05:04 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Jiri Kosina , Alan Stern , Jan Kara , Peter Chen , Florian Mickler , Linux-pm mailing list Hello, Rafael, Jiri. On Thu, Mar 17, 2016 at 12:24:57AM +0100, Rafael J. Wysocki wrote: > > There are no more writes happening to that region after userspace has been > > frozen. And we're definitely not getting rid of userspace freezing. > > > > Or have I missed the point of your question? > > I thought Tejun was talking about getting rid of userspace freezing. > Sorry if that was not the case. Oh, kthreads, definitely. Userland freezing doesn't cause any dependency issues in the kernel and I don't see any reason for changing userland part. > As I've already said for multiple times, I think that the freezing > should really be limited to user space as a rule. And in particular, > if freezing of any kernel threads or workqueues etc causes problems to > happen, the code using those freezable things is simply buggy and > needs to be fixed. Most likely by getting rid of the freezing from > it. We're in full agreement. Thanks. -- tejun