From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx114.postini.com [74.125.245.114]) by kanga.kvack.org (Postfix) with SMTP id 8B85B6B0002 for ; Wed, 27 Feb 2013 17:16:10 -0500 (EST) Received: by mail-pb0-f49.google.com with SMTP id xa12so636860pbc.8 for ; Wed, 27 Feb 2013 14:16:09 -0800 (PST) Date: Wed, 27 Feb 2013 14:16:07 -0800 (PST) From: David Rientjes Subject: Re: [patch] mm, show_mem: suppress page counts in non-blockable contexts In-Reply-To: <20130227100024.GA16724@dhcp22.suse.cz> Message-ID: References: <20130227100024.GA16724@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , Mel Gorman , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, 27 Feb 2013, Michal Hocko wrote: > But we are trying to prevent from soft lockups by calling > touch_nmi_watchdog every now when iterating over pages so the lock up > detector shouldn't trigger. > > Anyway, I think that the additional information (which can be really > costly as you are describing) is not that useful. Most of the useful > information is already printed by show_free_areas. Or does it help when > we know how much memory is shared/reserved/etc. when the allocation > fails? > I do not think it is helpful since show_free_areas() already shows all pertinent information, and hence I'm suppressing it in atomic contexts in this patch. > So I do agree with the dropping the additional information for the > allocation failure path (sysrq+m might still show it) but I fail to see > how the lockup detector plays any role here. Can we just drop it because > it is not that interesting and it is costly so it is not worth > bothering? > I would agree it is not interesting to debugging VM issues and is obviously very expensive. -- 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