From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e5.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m4U7hibb009336 for ; Fri, 30 May 2008 03:43:44 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m4U7hie9137110 for ; Fri, 30 May 2008 03:43:44 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m4U7hhKg016502 for ; Fri, 30 May 2008 03:43:44 -0400 Date: Fri, 30 May 2008 00:43:42 -0700 From: Nishanth Aravamudan Subject: Re: [RFC][PATCH 2/2] hugetlb: remove multi-valued proc files. Message-ID: <20080530074342.GD5021@us.ibm.com> References: <20080525142317.965503000@nick.local0.net> <20080525143452.841211000@nick.local0.net> <20080529063915.GC11357@us.ibm.com> <20080529064242.GD11357@us.ibm.com> <20080530035123.GB25792@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080530035123.GB25792@wotan.suse.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: linux-mm@kvack.org, kniht@us.ibm.com, andi@firstfloor.org, agl@us.ibm.com, abh@cray.com, joachim.deguara@amd.com List-ID: On 30.05.2008 [05:51:23 +0200], Nick Piggin wrote: > On Wed, May 28, 2008 at 11:42:42PM -0700, Nishanth Aravamudan wrote: > > Now that we present the same information in a cleaner way in sysfs, we > > can remove the duplicate information and interfaces from procfs (and > > consider them to be the legacy interface). The proc interface only > > controls the default hugepage size, which is either > > > > a) the first one specified via hugepagesz= on the kernel command-line, if any > > b) the legacy huge page size, otherwise > > > > All other hugepage size pool manipulations can occur through sysfs. > > > > Signed-off-by: Nishanth Aravamudan > > > > --- > > Note, this does end up making the manipulation and validation of > > multiple hstates impossible without sysfs enabled and mounted. As such, > > I don't think that's such a problem. The overlap between users with > no sysfs and those that use multiple hugepages won't be large. And > if any exist, they can specify at boot or come up with their own > customer solution. Yeah, like I said, I imagine the only ones that might care are sh folks and even there, I don't know their MMU well enough to know how big of a deal it is. > > I'm not sure if this is the right approach and perhaps we should be > > leaving the multi-valued proc files in place (but not as the preferred > > interface). Or we could present the values in procfs only if SYSFS is > > not enabled in the kernel? I imagine (but am not 100% sure) that the > > only current architecture where this might be important is SUPERH? > > I wouldn't worry too much. I think /proc/sys/vm/nr_hugepages etc > is better as one (the compat) value after we now have the sysfs > stuff. However /proc/meminfo is a little more tricky. Of course > the information does exist in sysfs too, but meminfo is also for > user reporting, so maybe it will be better to leave it multi > column? Yeah, I suppose it could be either way. I definitely agree the writable interfaces are cleaner single-valued. Thanks, Nish -- Nishanth Aravamudan IBM Linux Technology Center -- 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