From patchwork Tue Mar 26 16:47:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jerome Glisse X-Patchwork-Id: 10871625 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 7D77C186D for ; Tue, 26 Mar 2019 16:48:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 684B828D00 for ; Tue, 26 Mar 2019 16:48:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5C56F28D5D; Tue, 26 Mar 2019 16:48:23 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E0F9028D00 for ; Tue, 26 Mar 2019 16:48:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2AA746E080; Tue, 26 Mar 2019 16:48:22 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0D13F6E07C for ; Tue, 26 Mar 2019 16:48:11 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 761CCC04B2F6; Tue, 26 Mar 2019 16:48:10 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.20.6.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 53C89176B1; Tue, 26 Mar 2019 16:48:08 +0000 (UTC) From: jglisse@redhat.com To: linux-kernel@vger.kernel.org Subject: [PATCH v6 4/8] mm/mmu_notifier: contextual information for event enums Date: Tue, 26 Mar 2019 12:47:43 -0400 Message-Id: <20190326164747.24405-5-jglisse@redhat.com> In-Reply-To: <20190326164747.24405-1-jglisse@redhat.com> References: <20190326164747.24405-1-jglisse@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 26 Mar 2019 16:48:10 +0000 (UTC) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , kvm@vger.kernel.org, =?utf-8?b?UmFkaW0gS3LEjW0=?= =?utf-8?b?w6HFmQ==?= , dri-devel@lists.freedesktop.org, Michal Hocko , linux-mm@kvack.org, Ross Zwisler , Andrea Arcangeli , linux-rdma@vger.kernel.org, Jason Gunthorpe , Ralph Campbell , Arnd Bergmann , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Peter Xu , Rodrigo Vivi , Dan Williams , Felix Kuehling , Paolo Bonzini , Andrew Morton , =?utf-8?q?Christian_K=C3=B6nig?= Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Jérôme Glisse CPU page table update can happens for many reasons, not only as a result of a syscall (munmap(), mprotect(), mremap(), madvise(), ...) but also as a result of kernel activities (memory compression, reclaim, migration, ...). This patch introduce a set of enums that can be associated with each of the events triggering a mmu notifier. Latter patches take advantages of those enum values. - UNMAP: munmap() or mremap() - CLEAR: page table is cleared (migration, compaction, reclaim, ...) - PROTECTION_VMA: change in access protections for the range - PROTECTION_PAGE: change in access protections for page in the range - SOFT_DIRTY: soft dirtyness tracking Being able to identify munmap() and mremap() from other reasons why the page table is cleared is important to allow user of mmu notifier to update their own internal tracking structure accordingly (on munmap or mremap it is not longer needed to track range of virtual address as it becomes invalid). Signed-off-by: Jérôme Glisse Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: Christian König Cc: Joonas Lahtinen Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Jan Kara Cc: Andrea Arcangeli Cc: Peter Xu Cc: Felix Kuehling Cc: Jason Gunthorpe Cc: Ross Zwisler Cc: Dan Williams Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Michal Hocko Cc: Christian Koenig Cc: Ralph Campbell Cc: John Hubbard Cc: kvm@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-rdma@vger.kernel.org Cc: Arnd Bergmann --- include/linux/mmu_notifier.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index c8672c366f67..2386e71ac1b8 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -10,6 +10,36 @@ struct mmu_notifier; struct mmu_notifier_ops; +/** + * enum mmu_notifier_event - reason for the mmu notifier callback + * @MMU_NOTIFY_UNMAP: either munmap() that unmap the range or a mremap() that + * move the range + * + * @MMU_NOTIFY_CLEAR: clear page table entry (many reasons for this like + * madvise() or replacing a page by another one, ...). + * + * @MMU_NOTIFY_PROTECTION_VMA: update is due to protection change for the range + * ie using the vma access permission (vm_page_prot) to update the whole range + * is enough no need to inspect changes to the CPU page table (mprotect() + * syscall) + * + * @MMU_NOTIFY_PROTECTION_PAGE: update is due to change in read/write flag for + * pages in the range so to mirror those changes the user must inspect the CPU + * page table (from the end callback). + * + * @MMU_NOTIFY_SOFT_DIRTY: soft dirty accounting (still same page and same + * access flags). User should soft dirty the page in the end callback to make + * sure that anyone relying on soft dirtyness catch pages that might be written + * through non CPU mappings. + */ +enum mmu_notifier_event { + MMU_NOTIFY_UNMAP = 0, + MMU_NOTIFY_CLEAR, + MMU_NOTIFY_PROTECTION_VMA, + MMU_NOTIFY_PROTECTION_PAGE, + MMU_NOTIFY_SOFT_DIRTY, +}; + #ifdef CONFIG_MMU_NOTIFIER /*