From patchwork Thu Sep 10 18:33:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11768675 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B2B8059D for ; Thu, 10 Sep 2020 18:33:50 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7F31821D40 for ; Thu, 10 Sep 2020 18:33:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="BA9fXgzR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F31821D40 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 035BC6E97A; Thu, 10 Sep 2020 18:33:47 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id AF05C6E979 for ; Thu, 10 Sep 2020 18:33:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=iUQLI4IkKhxmuIt5IQ92wfzZNFFmlqJHR5Mjgm7VnoA=; b=BA9fXgzR2ABZNFehO2jFdouN4b iatHnAm3X02YEDHBkg5V7kpzguGHl7vVWOOyszawHEkfApPAg1CVxxTQddRDUlB2DXtjsIPebRC0H +RSun9FiyBLil2BxMQTak8vbiwPaq02YTFwtoCHfj3fHL9EVOeHaJFkRRGNvBNMkGf76k2ekSGR8w q+6P8md5vudIkfhhBaRydUlngTJBq7gdHAIuO2S8Wb8c5A7bhSSLnSPs5HtyvAHjness9QKziYg+o 4Su2kksd56Fv0Rz0NaXC5CIngX3owPQbylFWO6K+Gq+ygUkjYDxRzGzapwO8XsA13+zclT89KPb0o e7QRA3hQ==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kGRNq-0005Ge-AD; Thu, 10 Sep 2020 18:33:22 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Date: Thu, 10 Sep 2020 19:33:18 +0100 Message-Id: <20200910183318.20139-9-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200910183318.20139-1-willy@infradead.org> References: <20200910183318.20139-1-willy@infradead.org> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2 8/8] mm: Add find_lock_head X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Huang Ying , Hugh Dickins , linux-kernel@vger.kernel.org, Chris Wilson , William Kucharski , "Matthew Wilcox \(Oracle\)" , Johannes Weiner , cgroups@vger.kernel.org, Andrew Morton , Alexey Dobriyan , Matthew Auld Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Add a new FGP_HEAD flag which avoids calling find_subpage() and add a convenience wrapper for it. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 32 ++++++++++++++++++++++++++------ mm/filemap.c | 9 ++++++--- 2 files changed, 32 insertions(+), 9 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index f374618b2c93..4e52a3ff92fb 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -278,6 +278,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, #define FGP_NOFS 0x00000010 #define FGP_NOWAIT 0x00000020 #define FGP_FOR_MMAP 0x00000040 +#define FGP_HEAD 0x00000080 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset, int fgp_flags, gfp_t cache_gfp_mask); @@ -309,18 +310,37 @@ static inline struct page *find_get_page_flags(struct address_space *mapping, * @mapping: the address_space to search * @offset: the page index * - * Looks up the page cache slot at @mapping & @offset. If there is a + * Looks up the page cache entry at @mapping & @offset. If there is a * page cache page, it is returned locked and with an increased * refcount. * - * Otherwise, %NULL is returned. - * - * find_lock_page() may sleep. + * Context: May sleep. + * Return: A struct page or %NULL if there is no page in the cache for this + * index. */ static inline struct page *find_lock_page(struct address_space *mapping, - pgoff_t offset) + pgoff_t index) +{ + return pagecache_get_page(mapping, index, FGP_LOCK, 0); +} + +/** + * find_lock_head - Locate, pin and lock a pagecache page. + * @mapping: The address_space to search. + * @offset: The page index. + * + * Looks up the page cache entry at @mapping & @offset. If there is a + * page cache page, its head page is returned locked and with an increased + * refcount. + * + * Context: May sleep. + * Return: A struct page which is !PageTail, or %NULL if there is no page + * in the cache for this index. + */ +static inline struct page *find_lock_head(struct address_space *mapping, + pgoff_t index) { - return pagecache_get_page(mapping, offset, FGP_LOCK, 0); + return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0); } /** diff --git a/mm/filemap.c b/mm/filemap.c index 453535170b8d..e429e02317ef 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1659,6 +1659,8 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t index) * * * %FGP_ACCESSED - The page will be marked accessed. * * %FGP_LOCK - The page is returned locked. + * * %FGP_HEAD - If the page is present and a THP, return the head page + * rather than the exact page specified by the index. * * %FGP_CREAT - If no page is present then a new page is allocated using * @gfp_mask and added to the page cache and the VM's LRU list. * The page is returned locked and with an increased refcount. @@ -1687,7 +1689,6 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, page = NULL; if (!page) goto no_page; - page = find_subpage(page, index); if (fgp_flags & FGP_LOCK) { if (fgp_flags & FGP_NOWAIT) { @@ -1700,12 +1701,12 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, } /* Has the page been truncated? */ - if (unlikely(compound_head(page)->mapping != mapping)) { + if (unlikely(page->mapping != mapping)) { unlock_page(page); put_page(page); goto repeat; } - VM_BUG_ON_PAGE(page->index != index, page); + VM_BUG_ON_PAGE(!thp_contains(page, index), page); } if (fgp_flags & FGP_ACCESSED) @@ -1715,6 +1716,8 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, if (page_is_idle(page)) clear_page_idle(page); } + if (!(fgp_flags & FGP_HEAD)) + page = find_subpage(page, index); no_page: if (!page && (fgp_flags & FGP_CREAT)) {