From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] badness() dramatically overcounts memory From: Jeff Davis In-Reply-To: <47A7E282.1080902@linux.vnet.ibm.com> References: <1202182480.24634.22.camel@dogma.ljc.laika.com> <47A7E282.1080902@linux.vnet.ibm.com> Content-Type: text/plain Date: Tue, 05 Feb 2008 15:02:41 -0800 Message-Id: <1202252561.24634.64.camel@dogma.ljc.laika.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: balbir@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, 2008-02-05 at 09:43 +0530, Balbir Singh wrote: > 1. grep on the kernel source tells me that shared_vm is incremented only in > vm_stat_account(), which is a NO-OP if CONFIG_PROC_FS is not defined. I see, thanks for pointing that out. Is there another way do you think? Would the penalty be to high to enable vm_stat_account when CONFIG_PROC_FS is not defined? Or perhaps my patch would only have an effect when CONFIG_PROC_FS is set (which is default)? > 2. How have you tested these patches? One way to do it would be to use the > memory controller and set a small limit on the control group. A memory > intensive application will soon see an OOM. I have done a quick test a while back when I first wrote the patch. I will test more thoroughly now. > The interesting thing is the use of total_vm and not the RSS which is used as > the basis by the OOM killer. I need to read/understand the code a bit more. RSS makes more sense to me as well. To me, it makes no sense to count shared memory, because killing a process doesn't free the shared memory. Regards, Jeff Davis -- 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