From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx172.postini.com [74.125.245.172]) by kanga.kvack.org (Postfix) with SMTP id 545B06B0031 for ; Tue, 30 Jul 2013 03:45:35 -0400 (EDT) Date: Tue, 30 Jul 2013 09:45:31 +0200 From: Michal Hocko Subject: Re: [PATCH resend] drop_caches: add some documentation and info message Message-ID: <20130730074531.GA10584@dhcp22.suse.cz> References: <1374842669-22844-1-git-send-email-mhocko@suse.cz> <20130729135743.c04224fb5d8e64b2730d8263@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130729135743.c04224fb5d8e64b2730d8263@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com, kosaki.motohiro@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, bp@suse.de, Dave Hansen On Mon 29-07-13 13:57:43, Andrew Morton wrote: > On Fri, 26 Jul 2013 14:44:29 +0200 Michal Hocko wrote: [...] > > --- a/fs/drop_caches.c > > +++ b/fs/drop_caches.c > > @@ -59,6 +59,8 @@ int drop_caches_sysctl_handler(ctl_table *table, int write, > > if (ret) > > return ret; > > if (write) { > > + printk(KERN_INFO "%s (%d): dropped kernel caches: %d\n", > > + current->comm, task_pid_nr(current), sysctl_drop_caches); > > if (sysctl_drop_caches & 1) > > iterate_supers(drop_pagecache_sb, NULL); > > if (sysctl_drop_caches & 2) > > How about we do > > if (!(sysctl_drop_caches & 4)) > printk(....) > > so people can turn it off if it's causing problems? I am OK with that but can we use a top bit instead. Maybe we never have other entities to drop in the future but it would be better to have a room for them just in case. So what about using 1<<31 instead? -- Michal Hocko SUSE Labs -- 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