From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: [PATCH, RFC 02/16] mm: implement zero_huge_user_segment and friends Date: Mon, 28 Jan 2013 11:24:14 +0200 Message-ID: <1359365068-10147-3-git-send-email-kirill.shutemov@linux.intel.com> References: <1359365068-10147-1-git-send-email-kirill.shutemov@linux.intel.com> Cc: Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" To: Andrea Arcangeli , Andrew Morton , Al Viro Return-path: In-Reply-To: <1359365068-10147-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org From: "Kirill A. Shutemov" Let's add helpers to clear huge page segment(s). They provide the same functionallity as zero_user_segment{,s} and zero_user, but for huge pages. Signed-off-by: Kirill A. Shutemov --- include/linux/mm.h | 15 +++++++++++++++ mm/memory.c | 22 ++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index e4533a1..c011771 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1728,6 +1728,21 @@ extern void dump_page(struct page *page); extern void clear_huge_page(struct page *page, unsigned long addr, unsigned int pages_per_huge_page); +extern void zero_huge_user_segment(struct page *page, + unsigned start, unsigned end); +static inline void zero_huge_user_segments(struct page *page, + unsigned start1, unsigned end1, + unsigned start2, unsigned end2) +{ + zero_huge_user_segment(page, start1, end1); + zero_huge_user_segment(page, start2, end2); +} +static inline void zero_huge_user(struct page *page, + unsigned start, unsigned len) +{ + zero_huge_user_segment(page, start, start+len); +} + extern void copy_user_huge_page(struct page *dst, struct page *src, unsigned long addr, struct vm_area_struct *vma, unsigned int pages_per_huge_page); diff --git a/mm/memory.c b/mm/memory.c index c04078b..200a74d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4185,6 +4185,28 @@ void clear_huge_page(struct page *page, } } +void zero_huge_user_segment(struct page *page, unsigned start, unsigned end) +{ + int i; + + BUG_ON(end < start); + + might_sleep(); + + /* start and end are on the same small page */ + if ((start & PAGE_MASK) == (end & PAGE_MASK)) + return zero_user_segment(page + (start >> PAGE_SHIFT), + start & ~PAGE_MASK, end & ~PAGE_MASK); + + zero_user_segment(page + (start >> PAGE_SHIFT), + start & ~PAGE_MASK, PAGE_SIZE); + for (i = (start >> PAGE_SHIFT) + 1; i < (end >> PAGE_SHIFT) - 1; i++) { + cond_resched(); + clear_highpage(page + i); + } + zero_user_segment(page + i, 0, end & ~PAGE_MASK); +} + static void copy_user_gigantic_page(struct page *dst, struct page *src, unsigned long addr, struct vm_area_struct *vma, -- 1.7.10.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org