From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Date: Tue, 31 Mar 2015 22:10:33 +0000 Subject: Re: Possible regression in next-20150323 due to "ARM, arm64: kvm: get rid of the bounce page" Message-Id: <7h8uec95t2.fsf@deeprootsystems.com> List-Id: References: <20150324004537.GA24816@verge.net.au> <20150324161358.GA694@kahuna> <20150326003939.GA25368@verge.net.au> <20150326133631.GB2805@arm.com> <20150327002554.GA5527@verge.net.au> <20150327100612.GB1562@arm.com> <7hbnj99epe.fsf@deeprootsystems.com> In-Reply-To: (Ard Biesheuvel's message of "Tue, 31 Mar 2015 23:39:47 +0200") MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hi Ard, Ard Biesheuvel writes: [...] > I think Will and I were both under the impression that this patch > > https://git.kernel.org/cgit/linux/kernel/git/arm64/linux.git/log/?h=kvm-bounce-page > > fixed the issue conclusively. Nope, that branch is already part of linux-next, and linux-next still fails to compile for 20+ defconfigs[1] > Could you elaborate on the issue please? What is the error you are > getting, and can you confirm that is is caused by ld choking on the > linker script? If not, this is another error than the one we have been > trying to fix It's definitely not linker script related. Using "arm-linux-gnueabi-gcc (Ubuntu/Linaro 4.7.3-12ubuntu1) 4.7.3", here's the error when building for multi_v7_defconfig (full log available[2]): ../mm/migrate.c: In function 'migrate_pages': ../mm/migrate.c:1148:1: internal compiler error: in push_minipool_fix, at config/arm/arm.c:13101 Please submit a full bug report, with preprocessed source if appropriate. See for instructions. Preprocessed source stored into /tmp/ccO1Nz1m.out file, please attach this to your bugreport. make[2]: *** [mm/migrate.o] Error 1 make[2]: Target `__build' not remade because of errors. make[1]: *** [mm] Error 2 build bisect points to commit 21f992084aeb[3], but that doesn't revert cleanly so I haven't got any further than that yet. Kevin [1] http://kernelci.org/build/next/kernel/next-20150331/ [2] http://storage.kernelci.org/next/next-20150331/arm-multi_v7_defconfig/build.log [3] 21f992084aeb777675ba5f9c2dc6663e8a06e467 is the first bad commit Author: Kirill A. Shutemov Date: Wed Mar 25 13:02:28 2015 +1100 page-flags: define behavior of FS/IO-related flags on compound pages It seems we don't have compound page on FS/IO path currently. Use NO_COMPOUND to catch if we have. The odd exception is PG_dirty: sound uses compound pages and maps them with PTEs. NO_COMPOUND triggers VM_BUG_ON() in set_page_dirty() on handling shared fault. Let's use HEAD for PG_dirty. Signed-off-by: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Dave Hansen Cc: Mel Gorman Cc: Rik van Riel Cc: Vlastimil Babka Cc: Christoph Lameter Cc: Naoya Horiguchi Cc: Steve Capper Cc: "Aneesh Kumar K.V" Cc: Johannes Weiner Cc: Michal Hocko Cc: Jerome Marchand Signed-off-by: Andrew Morton :040000 040000 0d621460af1123de8fc33c881ae314c914725afc b843f45fb2a1c2537e8c17946d3f8af512cab84d M include bisect run success