From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-f71.google.com (mail-lf1-f71.google.com [209.85.167.71]) by kanga.kvack.org (Postfix) with ESMTP id 3BFBF6B0008 for ; Tue, 16 Oct 2018 13:44:14 -0400 (EDT) Received: by mail-lf1-f71.google.com with SMTP id y12-v6so1268240lfh.16 for ; Tue, 16 Oct 2018 10:44:14 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id m15-v6sor3966816lfh.11.2018.10.16.10.44.12 for (Google Transport Security); Tue, 16 Oct 2018 10:44:12 -0700 (PDT) From: Kuo-Hsin Yang Subject: [PATCH 1/2] shmem: export shmem_unlock_mapping Date: Wed, 17 Oct 2018 01:42:59 +0800 Message-Id: <20181016174300.197906-2-vovoy@chromium.org> In-Reply-To: <20181016174300.197906-1-vovoy@chromium.org> References: <20181016174300.197906-1-vovoy@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org Cc: mhocko@suse.com, akpm@linux-foundation.org, chris@chris-wilson.co.uk, peterz@infradead.org, dave.hansen@intel.com, corbet@lwn.net, hughd@google.com, joonas.lahtinen@linux.intel.com, marcheu@chromium.org, hoegsberg@chromium.org, Kuo-Hsin Yang By exporting this function, drivers can mark/unmark a shmemfs address space as unevictable in the following way: 1. mark an address space as unevictable with mapping_set_unevictable(), pages in the address space will be moved to unevictable list in vmscan. 2. mark an address space evictable with mapping_clear_unevictable(), and move these pages back to evictable list with shmem_unlock_mapping(). Signed-off-by: Kuo-Hsin Yang --- Documentation/vm/unevictable-lru.rst | 4 +++- mm/shmem.c | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/Documentation/vm/unevictable-lru.rst b/Documentation/vm/unevictable-lru.rst index fdd84cb8d511..a812fb55136d 100644 --- a/Documentation/vm/unevictable-lru.rst +++ b/Documentation/vm/unevictable-lru.rst @@ -143,7 +143,7 @@ using a number of wrapper functions: Query the address space, and return true if it is completely unevictable. -These are currently used in two places in the kernel: +These are currently used in three places in the kernel: (1) By ramfs to mark the address spaces of its inodes when they are created, and this mark remains for the life of the inode. @@ -154,6 +154,8 @@ These are currently used in two places in the kernel: swapped out; the application must touch the pages manually if it wants to ensure they're in memory. + (3) By the i915 driver to mark pinned address space until it's unpinned. + Detecting Unevictable Pages --------------------------- diff --git a/mm/shmem.c b/mm/shmem.c index 446942677cd4..d1ce34c09df6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -786,6 +786,7 @@ void shmem_unlock_mapping(struct address_space *mapping) cond_resched(); } } +EXPORT_SYMBOL_GPL(shmem_unlock_mapping); /* * Remove range of pages and swap entries from radix tree, and free them. @@ -3874,6 +3875,7 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user) void shmem_unlock_mapping(struct address_space *mapping) { } +EXPORT_SYMBOL_GPL(shmem_unlock_mapping); #ifdef CONFIG_MMU unsigned long shmem_get_unmapped_area(struct file *file, -- 2.19.1.331.ge82ca0e54c-goog