From patchwork Wed Aug 19 18:48:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11724887 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 3FF8F618 for ; Wed, 19 Aug 2020 18:49:11 +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 1E519207DE for ; Wed, 19 Aug 2020 18:49:11 +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="s/Fj5e9N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E519207DE 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 EDF096E5B4; Wed, 19 Aug 2020 18:49:08 +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 089946E5B0 for ; Wed, 19 Aug 2020 18:49:06 +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=p9w3DQmYzQVsLNeG7R7MdPybBJO6jXoNftILGTf+IE0=; b=s/Fj5e9N4i8MPBUyLdHzmYltJH W95qh4IqdO+bgeV/dKBXO34yVAYFsjEf92o4CweV2SCp098vES4xu2VCaPtffdljiQgVFusO0lPtR mVxJiPVCa8G/0SULJ8xl53dhiTptsPOCo1sLkBvQH4SedICuiVc6SD74X35sX59AOfjyMClCYGUzr 978Ku/CwTM5ej8GuG7J5Hwsz0uakDJFFzqaSPsaVyedNaFZ8G9IsmSt4Xk4MOwfTnNBgqvB1gV7u9 lDbXNqBWefAsnr4EO2lUpq8B6IotkPmE/O6f+kHf5745L3YB4RJNSt3UO0+ggGjOLpewsg3FA6VVz e6DXDilg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8T8p-0006UC-TJ; Wed, 19 Aug 2020 18:48:56 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Date: Wed, 19 Aug 2020 19:48:49 +0100 Message-Id: <20200819184850.24779-8-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200819184850.24779-1-willy@infradead.org> References: <20200819184850.24779-1-willy@infradead.org> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 7/8] mm: Return head page from find_lock_entry 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" Convert the one caller of find_lock_entry() to cope with a head page being returned instead of the subpage for the index. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 12 ++++++++++++ mm/filemap.c | 25 +++++++++++-------------- mm/shmem.c | 15 ++++++++------- 3 files changed, 31 insertions(+), 21 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 8261c64f592d..de8f3758ceaa 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -371,6 +371,18 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, mapping_gfp_mask(mapping)); } +/* + * Is this index for one of the subpages of this page? + * This should always be called for a locked, non-hugetlbfs page. + */ +static inline bool thp_valid_index(struct page *head, pgoff_t index) +{ + VM_BUG_ON_PAGE(PageHuge(head), head); + VM_BUG_ON_PAGE(!PageLocked(head), head); + + return head->index == (index & ~(thp_nr_pages(head) - 1)); +} + /* * Given the page we found in the page cache, return the page corresponding * to this index in the file diff --git a/mm/filemap.c b/mm/filemap.c index 5a87e1bdddd6..6594baae7cd2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1594,37 +1594,34 @@ struct page *find_get_entry(struct address_space *mapping, pgoff_t index) } /** - * find_lock_entry - locate, pin and lock a page cache entry - * @mapping: the address_space to search - * @offset: the page cache index + * find_lock_entry - Locate and lock a page cache entry. + * @mapping: The address_space to search. + * @index: The page cache index. * - * Looks up the page cache slot at @mapping & @offset. If there is a - * page cache page, it is returned locked and with an increased - * refcount. + * Looks up the page at @mapping & @index. If there is a page in the + * cache, the head page is returned locked and with an increased refcount. * * If the slot holds a shadow entry of a previously evicted page, or a * swap entry from shmem/tmpfs, it is returned. * - * find_lock_entry() may sleep. - * - * Return: the found page or shadow entry, %NULL if nothing is found. + * Context: May sleep. + * Return: The head page or shadow entry, %NULL if nothing is found. */ -struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset) +struct page *find_lock_entry(struct address_space *mapping, pgoff_t index) { struct page *page; repeat: - page = find_get_entry(mapping, offset); + page = find_get_entry(mapping, index); if (page && !xa_is_value(page)) { lock_page(page); /* Has the page been truncated? */ - if (unlikely(page_mapping(page) != mapping)) { + if (unlikely(page->mapping != mapping)) { unlock_page(page); put_page(page); goto repeat; } - page = find_subpage(page, offset); - VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page); + VM_BUG_ON_PAGE(!thp_valid_index(page, index), page); } return page; } diff --git a/mm/shmem.c b/mm/shmem.c index 271548ca20f3..bbb43e9d35df 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1834,8 +1834,9 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, page = NULL; } if (page || sgp == SGP_READ) { - *pagep = page; - return 0; + if (page && PageTransHuge(page)) + hindex = round_down(index, HPAGE_PMD_NR); + goto out; } /* @@ -1961,14 +1962,13 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, * it now, lest undo on failure cancel our earlier guarantee. */ if (sgp != SGP_WRITE && !PageUptodate(page)) { - struct page *head = compound_head(page); int i; - for (i = 0; i < compound_nr(head); i++) { - clear_highpage(head + i); - flush_dcache_page(head + i); + for (i = 0; i < compound_nr(page); i++) { + clear_highpage(page + i); + flush_dcache_page(page + i); } - SetPageUptodate(head); + SetPageUptodate(page); } /* Perhaps the file has been truncated since we checked */ @@ -1984,6 +1984,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, error = -EINVAL; goto unlock; } +out: *pagep = page + index - hindex; return 0;