From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [122.248.162.5]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp05.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 7668E2C00AB for ; Sun, 2 Jun 2013 17:23:08 +1000 (EST) Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 2 Jun 2013 12:48:32 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 34469125804F for ; Sun, 2 Jun 2013 12:55:04 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r527MqZq5833124 for ; Sun, 2 Jun 2013 12:52:53 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r527Mu3p016004 for ; Sun, 2 Jun 2013 17:22:56 +1000 From: "Aneesh Kumar K.V" To: Benjamin Herrenschmidt Subject: Re: 3.10-rc ppc64 corrupts usermem when swapping In-Reply-To: <1370038982.3928.147.camel@pasglop> References: <1369897236.3928.93.camel@pasglop> <87vc60na89.fsf@linux.vnet.ibm.com> <1369902786.3928.94.camel@pasglop> <1369978262.3928.111.camel@pasglop> <87ppw7mrx7.fsf@linux.vnet.ibm.com> <1370038982.3928.147.camel@pasglop> Date: Sun, 02 Jun 2013 12:52:56 +0530 Message-ID: <8738t1c6y7.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Cc: Paul Mackerras , Anton Blanchard , Hugh Dickins , linuxppc-dev@lists.ozlabs.org, David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Benjamin Herrenschmidt writes: > On Fri, 2013-05-31 at 14:45 +0530, Aneesh Kumar K.V wrote: > >> > The patch you are running on is what I'll send to Linus for 3.10 (+/- >> > cosmetics). Aneesh second patch is a much larger rework which will be >> > needed for THP but that will wait for 3.11. I'm happy for you to test it >> > but I first want to make sure it's solid with the 3.10 fix :-) > > BTW. One concern I still have is that Hugh identified the bad commit > to be: > > 7e74c3921ad9610c0b49f28b8fc69f7480505841 > "powerpc: Fix hpte_decode to use the correct decoding for page sizes". > > However, you introduce the return on HPTE not found earlier, in > > b1022fbd293564de91596b8775340cf41ad5214c > "powerpc: Decode the pte-lp-encoding bits correctly." > > So while I'm still happy with the current band-aid for 3.10 and am > about to send it to Linus, the above *does* seem to indicate that > there is also something wrong with the "Fix hpte_decode..." commit, > which might not actually get the page size right... > > Can you investigate ? 7e74c3921ad9610c0b49f28b8fc69f7480505841 "powerpc: Fix hpte_decode to use the correct decoding for page sizes" changes should only impact hpte_decode. We don't change the details of hpte_actual_psize at all in this patch. That means we should see a difference only with kexec right ?. Hugh, Will you be able to double check whether 7e74c3921ad9610c0b49f28b8fc69f7480505841 is the bad commit. The one before that is what we changed in the patch that fixed your problem. -aneesh