From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 27 Jan 2007 03:01:43 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC] Limit the size of the pagecache Message-Id: <20070127030143.3059dbb0.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20070126022955.f9b6b11f.akpm@osdl.org> References: <20070124121318.6874f003.kamezawa.hiroyu@jp.fujitsu.com> <20070124141510.7775829c.kamezawa.hiroyu@jp.fujitsu.com> <20070126022955.f9b6b11f.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: clameter@sgi.com, aubreylee@gmail.com, svaidy@linux.vnet.ibm.com, nickpiggin@yahoo.com.au, rgetz@blackfin.uclinux.org, Michael.Hennerich@analog.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Fri, 26 Jan 2007 02:29:55 -0800 Andrew Morton wrote: > On Wed, 24 Jan 2007 14:15:10 +0900 > KAMEZAWA Hiroyuki wrote: > > > - One for stability > > When a customer constructs their detabase(Oracle), the system often goes to oom. > > This is because that the system cannot allocate DMA_ZOME memory for 32bit device. > > (USB or e100) > > Not allowing to use almost all pages as page cache (for temporal use) will be some help. > > (Note: construction DB on ext3....so all writes are serialized and the system couldn't > > free page cache.) > > I'm surprised that any reasonable driver has a dependency on ZONE_DMA. Are > you sure? Send full oom-killer output, please. > > Our ia64 server's USB/e100 device uses 32bit-PCI, so sometimes OOM happens on DMA zone. (ia64's ZONE_DMA is 0-4G area.) But very sorry....I was confused. I looked the issue above again and found ZONE_NORMAL/x86 was exhausted. This was interesiting incident, Constructing DB on 4Gb system has no problem. Constructing DB on 8Gb system always causes OOM. I asked the users to change DB's parameter. (this happened on RHEL4/linux-2.6.9 series) > > And...some customers want to keep memory Free as much as possible. > > 99% memory usage makes insecure them ;) > > Tell them to do "echo 3 > /proc/sys/vm/drop_caches", then wait three minutes? Ah, maybe we can use it on RHEL5. We'll test it. thank you. Thanks, -Kamezawa -- 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