From patchwork Thu Aug 30 15:05:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10581977 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 971DD174A for ; Thu, 30 Aug 2018 15:06:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 849AC2793B for ; Thu, 30 Aug 2018 15:06:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 76A5D2C01E; Thu, 30 Aug 2018 15:06:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 081012793B for ; Thu, 30 Aug 2018 15:06:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=PrFLzy/aZZ0+hoxdv3bDQNFTCVeqXypMEWB846+ScI8=; b=ozZ 4uh4hJjDkzVTSAazUoqBOUDm9kVvHjpWzzcOMScgfgq7bG1qD3gzJlacPkD6l9lf4LF8Cr8gP/nCy pBIE6mOMvTZzNY6UcDVrCOO9yZo8sdoKZt3pSh/DbSGlkYVzPNH+Bu9oecfdUi+fukgul+O5vxDSd qFvhCJqwHa2XHDB/ZN9HArRRo1JiXHegZoelKj7rmD/CslCCw+t8TEr03Fa6zw1ZtoioDwhtY5N1y YMfXxc9yjSEhpQ5lQ15XJiPnFAbGWCGtkv4ZgJEtscBLveuDhB3KzYAUJrdFAOPlgiaZOpAktX9rx I+w5nQRyOyWs4/2VjcU636LtUJKe7Lg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fvOWH-0001my-GJ; Thu, 30 Aug 2018 15:06:01 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fvOWC-0001m1-Hh for linux-arm-kernel@lists.infradead.org; Thu, 30 Aug 2018 15:05:59 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0987B18A; Thu, 30 Aug 2018 08:05:45 -0700 (PDT) Received: from melchizedek.Emea.Arm.com (melchizedek.emea.arm.com [10.4.12.81]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 615753F5BC; Thu, 30 Aug 2018 08:05:43 -0700 (PDT) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] arm64: mm: always enable CONFIG_HOLES_IN_ZONE Date: Thu, 30 Aug 2018 16:05:32 +0100 Message-Id: <20180830150532.22745-1-james.morse@arm.com> X-Mailer: git-send-email 2.18.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180830_080556_599351_DE9C11F6 X-CRM114-Status: GOOD ( 12.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pavel Tatashin , Ard Biesheuvel , Catalin Marinas , Will Deacon , Michal Hocko , linux-mm@kvack.org, Mikulas Patocka , James Morse MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 6d526ee26ccd ("arm64: mm: enable CONFIG_HOLES_IN_ZONE for NUMA") only enabled HOLES_IN_ZONE for NUMA systems because the NUMA code was choking on the missing zone for nomap pages. This problem doesn't just apply to NUMA systems. If the architecture doesn't set HAVE_ARCH_PFN_VALID, pfn_valid() will return true if the pfn is part of a valid sparsemem section. When working with multiple pages, the mm code uses pfn_valid_within() to test each page it uses within the sparsemem section is valid. On most systems memory comes in MAX_ORDER_NR_PAGES chunks which all have valid/initialised struct pages. In this case pfn_valid_within() is optimised out. Systems where this isn't true (e.g. due to nomap) should set HOLES_IN_ZONE and provide HAVE_ARCH_PFN_VALID so that mm tests each page as it works with it. Currently non-NUMA arm64 systems can't enable HOLES_IN_ZONE, leading to VM_BUG_ON(): | page:fffffdff802e1780 is uninitialized and poisoned | raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff | raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff | page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) | ------------[ cut here ]------------ | kernel BUG at include/linux/mm.h:978! | Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [...] | CPU: 1 PID: 25236 Comm: dd Not tainted 4.18.0 #7 | Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 | pstate: 40000085 (nZcv daIf -PAN -UAO) | pc : move_freepages_block+0x144/0x248 | lr : move_freepages_block+0x144/0x248 | sp : fffffe0071177680 [...] | Process dd (pid: 25236, stack limit = 0x0000000094cc07fb) | Call trace: | move_freepages_block+0x144/0x248 | steal_suitable_fallback+0x100/0x16c | get_page_from_freelist+0x440/0xb20 | __alloc_pages_nodemask+0xe8/0x838 | new_slab+0xd4/0x418 | ___slab_alloc.constprop.27+0x380/0x4a8 | __slab_alloc.isra.21.constprop.26+0x24/0x34 | kmem_cache_alloc+0xa8/0x180 | alloc_buffer_head+0x1c/0x90 | alloc_page_buffers+0x68/0xb0 | create_empty_buffers+0x20/0x1ec | create_page_buffers+0xb0/0xf0 | __block_write_begin_int+0xc4/0x564 | __block_write_begin+0x10/0x18 | block_write_begin+0x48/0xd0 | blkdev_write_begin+0x28/0x30 | generic_perform_write+0x98/0x16c | __generic_file_write_iter+0x138/0x168 | blkdev_write_iter+0x80/0xf0 | __vfs_write+0xe4/0x10c | vfs_write+0xb4/0x168 | ksys_write+0x44/0x88 | sys_write+0xc/0x14 | el0_svc_naked+0x30/0x34 | Code: aa1303e0 90001a01 91296421 94008902 (d4210000) | ---[ end trace 1601ba47f6e883fe ]--- Remove the NUMA dependency. Reported-by: Mikulas Patocka Link: https://www.spinics.net/lists/arm-kernel/msg671851.html Fixes: 6d526ee26ccd ("arm64: mm: enable CONFIG_HOLES_IN_ZONE for NUMA") CC: Ard Biesheuvel Signed-off-by: James Morse Reviewed-by: Pavel Tatashin Tested-by: Mikulas Patocka Acked-by: Michal Hocko --- arch/arm64/Kconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 29e75b47becd..1b1a0e95c751 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -763,7 +763,6 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK config HOLES_IN_ZONE def_bool y - depends on NUMA source kernel/Kconfig.hz