From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 7 May 2000 17:16:49 -0600 (MDT) From: jgg@debian.org Reply-To: Jason Gunthorpe Subject: UltraSPARC MM issue Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Linux-MM@kvack.org Cc: "David S. Miller" List-ID: Hi, I had a chat with Rik van Riel on IRC today, and he suggested making a posting about my findings to the linux-mm list. There is a problem with the UltraSPARC port of linux. The basic issue is that the Ultra port uses order 2 pages when allocating PTEs (see ./arch/sparc64/mm/init.c:get_pte_slow). It is quite easy to cause enough memory fragmentation that these allocations begin to fail which leads to either an OOM-type situation or an Oops. Either way the machine pretty much goes down. I hope someone will feel inspired to work on this sometime over the 2.5 release cycle.. A little background: Sun donated to Debian a rather large UltraSPARC with a really big RAID for use as our root archive server. It turns out that our archive maint scripts cause severe memory fragmentation and show this problem really easially.. Thanks, Jason Debian -- 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.eu.org/Linux-MM/