From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from parcelfarce.linux.theplanet.co.uk (parcelfarce.linux.theplanet.co.uk [195.92.249.252]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 40AAB67A6D for ; Wed, 23 Mar 2005 05:25:54 +1100 (EST) Date: Tue, 22 Mar 2005 10:04:26 -0300 From: Marcelo Tosatti To: Guillaume Autran Message-ID: <20050322130426.GE2498@logos.cnet> References: <28F2CE72-0BF0-11D9-97DC-003065F9B7DC@embeddededge.com> <20050210150437.GA19134@logos.cnet> <20050210170658.GA20153@logos.cnet> <20050210170859.GB20153@logos.cnet> <423F4071.1000001@mrv.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <423F4071.1000001@mrv.com> Cc: "Smith, Craig" , paulus@samba.org, linux-ppc-embedded Subject: Re: Linux 2.6.x on 8xx status List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Mar 21, 2005 at 04:45:21PM -0500, Guillaume Autran wrote: > Hi, > > Was there any progress made about this issue or is it still pending ? That one is still pending. There are other issues in 8xx which are probably related to it, as follows. > I'm running 2.6.11 and still see the problem... I'm currently trying to understand 8xx cache structure and VM semantics to find out why I'm seeing the following numbers. Test application is: copy 16M from /dev/zero to file-on-RAMDISK, using: # dd if=/dev/zero of=file bs=4k count=3840 v2.6: I-TLB userspace misses: 141264 I-TLB kernel misses: 117455 D-TLB userspace misses: 217590 D-TLB kernel misses: 202677 tlbie: 260 I-TLB userspace misses: 143455 I-TLB kernel misses: 119189 D-TLB userspace misses: 212828 D-TLB kernel misses: 197883 tlbie: 260 I-TLB userspace misses: 142248 I-TLB kernel misses: 118195 D-TLB userspace misses: 217576 D-TLB kernel misses: 202663 tlbie: 260 v2.4: I-TLB userspace misses: 266 I-TLB kernel misses: 5170 D-TLB userspace misses: 3661 D-TLB kernel misses: 177004 tlbie: 162599 I-TLB userspace misses: 266 I-TLB kernel misses: 3183 D-TLB userspace misses: 2024 D-TLB kernel misses: 180178 tlbie: 165675 I'm quite puzzled. Why v2.6 calls the "tlbie" instruction 100-or-so less times than v2.4 ? Paul, Ben? > > Regards, > Guillaume. > > > > Marcelo Tosatti wrote: > > >On Thu, Feb 10, 2005 at 03:06:58PM -0200, Marcelo Tosatti wrote: > > > > > >>On Thu, Feb 10, 2005 at 02:26:52PM -0500, Dan Malek wrote: > >> > >> > >>>On Feb 10, 2005, at 10:04 AM, Marcelo Tosatti wrote: > >>> > >>> > >>> > >>>>Does anyone have a clue of what is/can be wrong with the TLB entry for > >>>>the > >>>>address being flushed at __flush_dcache_icache()? > >>>> > >>>> > >>>Not sure. The problem is that the __flush_dcache_icache is passed a > >>>user space virtual address that doesn't look like it is mapped for > >>>writing > >>>or something. I don't know, as an ooops isn't sufficient to debug the > >>>problem. > >>>You have to catch it here and track down the current state of the TLB > >>>and > >>>the page tables. Of course, when I do this everything looks OK, > >>> > >>> > >>How do you do track down the current TLB state? With a BDI? > >> > >> > >> > >>>so what I've been trying to do is catch the TLBmiss reload that actually > >>>causes this > >>>to happen to see what it really tried to load into the tlb. > >>> > >>> > >>Shouldnt it be loading the TLB entry which "seem to be OK" accordingly to > >>your > >>analysis ?? > >> > >> > > > >So this assumption which you have made sometime ago is wrong, given that > >now you know TLB entry is not stale ? > > > >"The symptom is we appear to have a stale TLB entry, > >so at least one of the callouts from the generic VM > >code isn't doing the right thing for us. I'm still > >puzzled as to why it doesn't affect other PPC processor." > > > >_______________________________________________ > >Linuxppc-embedded mailing list > >Linuxppc-embedded@ozlabs.org > >https://ozlabs.org/mailman/listinfo/linuxppc-embedded > > > > > > > > -- > ======================================= > Guillaume Autran > Senior Software Engineer > MRV Communications, Inc. > Tel: (978) 952-4932 office > E-mail: gautran@mrv.com > ======================================= >