From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f53.google.com (mail-pa0-f53.google.com [209.85.220.53]) by kanga.kvack.org (Postfix) with ESMTP id 83C5B6B0254 for ; Mon, 24 Aug 2015 16:30:45 -0400 (EDT) Received: by padfo6 with SMTP id fo6so1227396pad.3 for ; Mon, 24 Aug 2015 13:30:45 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id y15si29171808pbt.204.2015.08.24.13.30.44 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 24 Aug 2015 13:30:44 -0700 (PDT) Date: Mon, 24 Aug 2015 13:30:43 -0700 From: Andrew Morton Subject: Re: [PATCH] mm/khugepaged: Allow to interrupt allocation sleep again Message-Id: <20150824133043.23b66633b5c9c91bd6aae190@linux-foundation.org> In-Reply-To: <1440429203-4039-1-git-send-email-pmladek@suse.com> References: <1440429203-4039-1-git-send-email-pmladek@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Petr Mladek Cc: Andrea Arcangeli , Vlastimil Babka , "Aneesh Kumar K.V" , "Kirill A. Shutemov" , David Rientjes , Ebru Akagunduz , Mel Gorman , linux-mm@kvack.org, linux-pm@vger.kernel.org, Jiri Kosina On Mon, 24 Aug 2015 17:13:23 +0200 Petr Mladek wrote: > The commit 1dfb059b9438633b0546 ("thp: reduce khugepaged freezing > latency") fixed khugepaged to do not block a system suspend. But > the result is that it could not get interrupted before the given > timeout because the condition for the wait event is "false". What are the userspace-visible effects of this bug? > This patch puts back the original approach but it uses > freezable_schedule_timeout_interruptible() instead of > schedule_timeout_interruptible(). It does the right thing. > I am pretty sure that the freezable variant was not used in > the original fix only because it was not available at that time. > > The regression has been there for ages. It was not critical. It just > did the allocation throttling a little bit more aggressively. > > I found this problem when converting the kthread to kthread worker API > and trying to understand the code. > > ... -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org