From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: [PATCH] Simplify memory controller and resource counter I/O Date: Fri, 05 Oct 2007 09:15:46 +0530 Message-ID: <4705B36A.7000301@linux.vnet.ibm.com> References: <46F9DD4F.50806@google.com> <6599ad830710041755w3ed8b1fgd3dfbe7a8e0fc6c5@mail.gmail.com> <4705B02E.8040701@linux.vnet.ibm.com> <6599ad830710042038g6066d8b0i9308244d2710e563@mail.gmail.com> Reply-To: balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6599ad830710042038g6066d8b0i9308244d2710e563-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Paul Menage Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: containers.vger.kernel.org Paul Menage wrote: > On 10/4/07, Balbir Singh wrote: >> Forbidding writing to the root resource counter is a policy decision >> I am unable to make up my mind about. It sounds right, but unless >> we have a notion of unlimited resources, I am a bit concerned about >> taking away this flexibility. > > One big reason for doing this is to make virtualization easier - if > you expect not to be able to write to your root cgroup's limits files, > then it's easier to make them non-writeable for a virtual server. > Can't we handle that through file system permissions? virtual servers will not run as root >>>> One arguable drawback to this patch is that the use of memparse() is >>>> lost in the cleanup. Having said that, given the existing of shell >>>> arithmetic, it's not clear to me that typing >>>> >> memparse(), makes it so much easier, we need to use it. >> >>>> echo $[2<<30] > memory.limit >>>> >> Very geeky! I don't like it personally > > Why do you dislike it? Do you really believe that anyone using this > interface by hand isn't going to know that MB is 2^20 and GB is 2^30? > But system administrators deal with memory in MB and GB. When you go to buy memory, you don't specify, I need 1 << 30 or 2^30 bytes of memory :-). Most administrators track their memory using these quantifiers. >> Do read_uint() and write_uint(), just read and write unsigned >> integers? > > Correct. > Oops.. that would be problem, what if I wanted to set my limit to unsigned long long max? > Paul -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL