From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28esmtp03.in.ibm.com (8.13.1/8.13.1) with ESMTP id m1KFPAie013410 for ; Wed, 20 Feb 2008 20:55:10 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1KFPA8d897052 for ; Wed, 20 Feb 2008 20:55:10 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id m1KFP9PY031743 for ; Wed, 20 Feb 2008 15:25:09 GMT Message-ID: <47BC4554.10304@linux.vnet.ibm.com> Date: Wed, 20 Feb 2008 20:50:52 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [PATCH] Document huge memory/cache overhead of memory controller in Kconfig References: <20080220122338.GA4352@basil.nowhere.org> <47BC2275.4060900@linux.vnet.ibm.com> <18364.16552.455371.242369@stoffel.org> In-Reply-To: <18364.16552.455371.242369@stoffel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: John Stoffel Cc: Andi Kleen , akpm@osdl.org, torvalds@osdl.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: John Stoffel wrote: > I know this is a pedantic comment, but why the heck is it called such > a generic term as "Memory Controller" which doesn't give any > indication of what it does. > > Shouldn't it be something like "Memory Quota Controller", or "Memory > Limits Controller"? > It's called the memory controller since it controls the amount of memory that a user can allocate (via limits). The generic term for any resource manager plugged into cgroups is a controller. If you look through some of the references in the document, we've listed our plans to support other categories of memory as well. Hence it's called a memory controller > Also, the Kconfig name "CGROUP_MEM_CONT" is just wrong, it should be > "CGROUP_MEM_CONTROLLER", just spell it out so it's clear what's up. > This has some history as well. Control groups was called containers earlier. That way a name like CGROUP_MEM_CONT could stand for cgroup memory container or cgroup memory controller. > It took me a bunch of reading of Documentation/controllers/memory.txt > to even start to understand what the purpose of this was. The > document could also use a re-writing to include a clear introduction > at the top to explain "what" a memory controller is. > > Something which talks about limits, resource management, quotas, etc > would be nice. > The references, specially reference [1] contains a lot of details on limits, guarantees, etc. Since they've been documented in the past on lkml, I decided to keep them out of the documentation and mention them as references. If it's going to help to add that terminology; I can create another document describing what resource management means and what the commonly used terms mean. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL -- 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