Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754147Ab3DKUFW (ORCPT ); Thu, 11 Apr 2013 16:05:22 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:36660 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753650Ab3DKUFU (ORCPT ); Thu, 11 Apr 2013 16:05:20 -0400 Date: Thu, 11 Apr 2013 13:05:18 -0700 From: Greg Kroah-Hartman To: Dan Magenheimer Cc: Wanpeng Li , Seth Jennings , Konrad Rzeszutek Wilk , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Bob Liu Subject: Re: [PATCH 02/10] staging: zcache: remove zcache_freeze Message-ID: <20130411200518.GA5268@kroah.com> References: <1365553560-32258-1-git-send-email-liwanp@linux.vnet.ibm.com> <1365553560-32258-3-git-send-email-liwanp@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1498 Lines: 33 On Thu, Apr 11, 2013 at 10:13:42AM -0700, Dan Magenheimer wrote: > > From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com] > > Subject: [PATCH 02/10] staging: zcache: remove zcache_freeze > > > > The default value of zcache_freeze is false and it won't be modified by > > other codes. Remove zcache_freeze since no routine can disable zcache > > during system running. > > > > Signed-off-by: Wanpeng Li > > I'd prefer to leave this code in place as it may be very useful > if/when zcache becomes more tightly integrated into the MM subsystem > and the rest of the kernel. And the subtleties for temporarily disabling > zcache (which is what zcache_freeze does) are non-obvious and > may cause data loss so if someone wants to add this functionality > back in later and don't have this piece of code, it may take > a lot of pain to get it working. > > Usage example: All CPUs are fully saturated so it is questionable > whether spending CPU cycles for compression is wise. Kernel > could disable zcache using zcache_freeze. (Yes, a new entry point > would need to be added to enable/disable zcache_freeze.) > > My two cents... others are welcome to override. I will not override, and did not take this patch. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/