From owner-freebsd-mips@FreeBSD.ORG Fri Mar 19 19:48:19 2010 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3B387106566B for ; Fri, 19 Mar 2010 19:48:19 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id EB1F88FC12 for ; Fri, 19 Mar 2010 19:48:18 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.3/8.14.1) with ESMTP id o2JJi67R082720; Fri, 19 Mar 2010 13:44:06 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Fri, 19 Mar 2010 13:44:24 -0600 (MDT) Message-Id: <20100319.134424.200754750132956859.imp@bsdimp.com> To: neelnatu@gmail.com From: "M. Warner Losh" In-Reply-To: References: <98a59be81003190518h32b118d3t79927954c92f933a@mail.gmail.com> X-Mailer: Mew version 6.3 on Emacs 22.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-mips@freebsd.org Subject: Re: PATCH: enable use of memory beyond kseg0 X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Mar 2010 19:48:19 -0000 In message: Neel Natu writes: : Hi JC, : : On Fri, Mar 19, 2010 at 5:18 AM, C. Jayachandran : wrote: : > On Tue, Mar 16, 2010 at 7:05 AM, Neel Natu wrote: : >> This patch enables use of physical memory that is beyond the direct : >> mapped kseg0 region. : >> : >> The basic idea is to use KVA from the kseg2 region for mapping page : >> table pages that lie beyond the direct mapped region. : >> : >> The TLB miss handler can now recursively fault into the TLB invalid : >> handler if it dereferences a kseg2 page table page address that is not : >> in the TLB. The TLB invalid handler had to be extensively modified but : >> in the end came out much cleaner. : >> : >> I have tested this on a uni and multi-processor Sibyte with 1GB of : >> memory. It would be useful if this patch had some independent testing : >> as well. : >> : >> Please review. : >> : >> http://people.freebsd.org/~neel/mips_beyond_kseg.diff : > : > This fixes the crash I was seeing during 'make -j16 buildworld' on : > XLR. The buildworld completed after running about 6 hours over NFS : > mounted src and obj dir, so the patch looks good. I haven't done any : > performance comparisons yet. : > : : Thanks a lot for taking the time and effort to test this - much appreciated. I think you can go ahead and commit it. My eyeball review makes me think it will work. I've not had a chance to try them out on my Octeon board, but don't let my lack of time hold this up now that we know it helps XLR. Warner