From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 17 Aug 2003 08:54:18 +0200 From: Christoph Hellwig Subject: Re: [uClinux-dev] uClinux 2.6.x memory allocator brokenness Message-ID: <20030817065417.GA16969@lst.de> References: <200308162245.16480.bernie@develer.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200308162245.16480.bernie@develer.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Bernardo Innocenti Cc: linux-mm@kvack.org, uClinux development list List-ID: The right list for this would be linux-mm I guess.. On Sat, Aug 16, 2003 at 10:45:16PM +0200, Bernardo Innocenti wrote: > Hello, > > not sure if anybody else experienced this problem. 2.5.x/2.6.x > kernels seem to have some nasty bug in mm/page_alloc.c. > > When I allocate over 256KB of memory, the allocator steps into > __alloc_pages() with order=7 and finds nothing free in the 512KB > slab, then it splits the 1MB block in two 512MB blocks and fails > miserably for some unknown reason. > > I also noticed that any allocation (even smaller ones) always > fail in the fast path and falls down into the slowish code > that wakes up kswapd to free some more pages. > > This happens because zone->pages_low is set to 512 while > free_pages is consistently below 400 on my system. > > Perhaps these values would have to be retuned on embedded targets. > > -- > // Bernardo Innocenti - Develer S.r.l., R&D dept. > \X/ http://www.develer.com/ > > Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html > > > _______________________________________________ > uClinux-dev mailing list > uClinux-dev@uclinux.org > http://mailman.uclinux.org/mailman/listinfo/uclinux-dev > This message was resent by uclinux-dev@uclinux.org ---end quoted text--- -- 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: aart@kvack.org