From patchwork Wed Feb 7 06:54:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 10204673 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CA3D260247 for ; Wed, 7 Feb 2018 07:13:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A524028E2B for ; Wed, 7 Feb 2018 07:13:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 98A4228E2D; Wed, 7 Feb 2018 07:13:53 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2009428E2B for ; Wed, 7 Feb 2018 07:13:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753468AbeBGHNi (ORCPT ); Wed, 7 Feb 2018 02:13:38 -0500 Received: from mga06.intel.com ([134.134.136.31]:24519 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752682AbeBGHNf (ORCPT ); Wed, 7 Feb 2018 02:13:35 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Feb 2018 23:13:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,471,1511856000"; d="scan'208";a="16151230" Received: from devel-ww.sh.intel.com ([10.239.48.110]) by fmsmga008.fm.intel.com with ESMTP; 06 Feb 2018 23:13:32 -0800 From: Wei Wang To: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org Cc: pbonzini@redhat.com, wei.w.wang@intel.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com, huangzhichao@huawei.com Subject: [PATCH v27 3/4] mm/page_poison: expose page_poisoning_enabled to kernel modules Date: Wed, 7 Feb 2018 14:54:30 +0800 Message-Id: <1517986471-15185-4-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1517986471-15185-1-git-send-email-wei.w.wang@intel.com> References: <1517986471-15185-1-git-send-email-wei.w.wang@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In some usages, e.g. virtio-balloon, a kernel module needs to know if page poisoning is in use. This patch exposes the page_poisoning_enabled function to kernel modules. Signed-off-by: Wei Wang Cc: Andrew Morton Cc: Michal Hocko Cc: Michael S. Tsirkin --- mm/page_poison.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/page_poison.c b/mm/page_poison.c index e83fd44..c08d02a 100644 --- a/mm/page_poison.c +++ b/mm/page_poison.c @@ -30,6 +30,11 @@ bool page_poisoning_enabled(void) debug_pagealloc_enabled())); } +/** + * page_poisoning_enabled - check if page poisoning is enabled + * + * Return true if page poisoning is enabled, or false if not. + */ static void poison_page(struct page *page) { void *addr = kmap_atomic(page); @@ -37,6 +42,7 @@ static void poison_page(struct page *page) memset(addr, PAGE_POISON, PAGE_SIZE); kunmap_atomic(addr); } +EXPORT_SYMBOL_GPL(page_poisoning_enabled); static void poison_pages(struct page *page, int n) {