From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH 0/3] cpufreq: governor: Fix potential races Date: Thu, 4 Jun 2015 12:12:02 +0530 Message-ID: <20150604064202.GI11325@linux> References: <556FDEA8.6090801@linux.vnet.ibm.com> <556FEB4B.1010601@linux.vnet.ibm.com> <20150604061128.GF11325@linux> <556FF201.8080100@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pd0-f182.google.com ([209.85.192.182]:35966 "EHLO mail-pd0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751387AbbFDGmH (ORCPT ); Thu, 4 Jun 2015 02:42:07 -0400 Received: by pdjm12 with SMTP id m12so24195064pdj.3 for ; Wed, 03 Jun 2015 23:42:07 -0700 (PDT) Content-Disposition: inline In-Reply-To: <556FF201.8080100@linux.vnet.ibm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Preeti U Murthy Cc: Rafael Wysocki , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, ego@linux.vnet.ibm.com, paulus@samba.org, shilpa.bhat@linux.vnet.ibm.com, prarit@redhat.com, robert.schoene@tu-dresden.de, skannan@codeaurora.org On 04-06-15, 12:06, Preeti U Murthy wrote: > Your fix may not be complete and here is why. The reason we see the crash > is because we have *only* attempted to serialize calls to cpufreq_governor_dbs() > and not attempted to serialize *entire logical sequence of operations*. Let's > take a look at what is happening as a consequence. You missed my logs (For the first time in my life I wrote them so well). This is what I mentioned in 3/3: " These two issues need to be solved separately and the responsibility should be properly divided between cpufreq and governor core. The first problem is more about the governor core, as it needs to protect its structures properly. And the second problem should be fixed in cpufreq core instead of governor, as its all about sequence of events. This patch is trying to solve only the first problem. " I NEVER claimed that I solved all the issues. -- viresh