From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx177.postini.com [74.125.245.177]) by kanga.kvack.org (Postfix) with SMTP id 080B46B0032 for ; Fri, 12 Jul 2013 15:08:31 -0400 (EDT) Received: by mail-qc0-f174.google.com with SMTP id m15so5143956qcq.19 for ; Fri, 12 Jul 2013 12:08:31 -0700 (PDT) Message-ID: <51E0543A.5040906@gmail.com> Date: Fri, 12 Jul 2013 15:08:42 -0400 From: KOSAKI Motohiro MIME-Version: 1.0 Subject: Re: [-] drop_caches-add-some-documentation-and-info-messsge.patch removed from -mm tree References: <51ddc31f.zotz9WDKK3lWXtDE%akpm@linux-foundation.org> <20130711073644.GB21667@dhcp22.suse.cz> <20130711145034.3ec774d0a44742cf5d8e1177@linux-foundation.org> <20130712115028.GC15307@dhcp22.suse.cz> In-Reply-To: <20130712115028.GC15307@dhcp22.suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , kosaki.motohiro@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org, Borislav Petkov , Dave Hansen , kosaki.motohiro@gmail.com (7/12/13 7:50 AM), Michal Hocko wrote: > On Thu 11-07-13 14:50:34, Andrew Morton wrote: >> On Thu, 11 Jul 2013 09:36:44 +0200 Michal Hocko wrote: >> >>> On Wed 10-07-13 13:25:03, Andrew Morton wrote: >>> [...] >>>> This patch was dropped because it has gone stale >>> >>> Is there really a strong reason to not take this patch? >> >> I flushed out a whole bunch of MM patches which had been floating >> around in indecisive limbo. >> >> I don't recall all the review issues surrounding this one. > > Kosaki was concerned about annoying number of messages if somebody drops > caches too often (https://lkml.org/lkml/2010/9/20/450). As I noted in > the changelog > " > Kosaki was worried about possible excessive logging when somebody drops > caches too often (but then he claimed he didn't have a strong opinion on > that) but I would say opposite. If somebody does that then I would really > like to know that from the log when supporting a system because it almost > for sure means that there is something fishy going on. It is also worth > mentioning that only root can write drop caches so this is not an flooding > attack vector. > " > > Kosaki then Acked the patch. > > You were worried (http://lkml.indiana.edu/hypermail/linux/kernel/1210.3/00605.html) > about people hating us because they are using this as a solution to > their issues. I concur that most of those are just hacks that found > their way into scripts looong time agon and stayed there. > > Boris then noted (http://lkml.indiana.edu/hypermail/linux/kernel/1210.3/00659.html) > that he is using drop_caches to make s2ram faster but as others noted > this just adds the overhead to the resume path so it might work only for > certain use cases so a user space solution is more appropriate and > Boris' use case really sounds valid. > > As a compromise I can lower the log level. Would KERN_INFO work for > you? Or even KERN_DEBUG? > > I still find printk less intrusive than fiddling with vmstat counters. Michal, It's ok to go IMHO. However, please open new thread w/ a rebased patch. Many developers don't pay attention a lot to -mm automatic notifications. Thanks. -- 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