From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Zhang Subject: Re: Page Allocation Failure with e1000 using jumboframe Date: Fri, 19 Aug 2005 13:52:24 -0400 Message-ID: <1124473944.5552.22.camel@localhost.localdomain> References: <1124326404.5546.215.camel@localhost.localdomain> <1124470909.5552.11.camel@localhost.localdomain> Reply-To: mingz@ele.uri.edu Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: E1000 , iet-dev , netdev@vger.kernel.org Return-path: To: Jesse Brandeburg In-Reply-To: Sender: e1000-devel-admin@lists.sourceforge.net Errors-To: e1000-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: List-Id: netdev.vger.kernel.org On Fri, 2005-08-19 at 10:33 -0700, Jesse Brandeburg wrote: > On Fri, 19 Aug 2005, Ming Zhang wrote: > > This is first reported on IET list and then i redo the test with vanilla > > 2.6.12.4 kernel and everything went fine. > > > > so i suspect if there are special case caused by vendor kernel. > > > > is this 32KB ATOMIC ram allocation request only available in jumbo frame > > case? since the regular MTU case goes fine. > > > > Ahh, okay. I'm pretty sure that SuSE did some changes (not sure what) to > memory management. > > the formula for the size that the current e1000 looks for is something > like > > a = MTU roundup to next power of 2 > a += 2 (skb_reserve(NET_IP_ALIGN)) > a += 16 (skb_reserve 16 by __dev_alloc_skb) > > so, a = 2048 + 2 + 16, or 2066 > request (a) from slab, which does a power of 2 roundup > so the skb comes from the 4k (single page) slab for standard mtu. > that is wasteful. > Jesse > > PS we have a driver in test that won't do the large contig allocations any > more. > then wait to see this. :P ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf