From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 097C6C433E0 for ; Wed, 10 Jun 2020 20:17:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC4472074B for ; Wed, 10 Jun 2020 20:17:02 +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="HoAnYGt/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730927AbgFJURC (ORCPT ); Wed, 10 Jun 2020 16:17:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730536AbgFJUNt (ORCPT ); Wed, 10 Jun 2020 16:13:49 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21ADFC08C5CB; Wed, 10 Jun 2020 13:13:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=5TnSyW1Zm44ghLTpiBh1vxVIfpAZiM8VRVnGQzkBos0=; b=HoAnYGt/Qu5AdQzbQrAIYqUMJi S65+OguqCX6m+LtbZNviyhLWcfjuK2yg8Jm2YDpYlFi9ZsaboH4MWW7atwRUtvermomPgj9uKul0E UIk2S3YAk3keYTFtdRm3+nAIZBlt7WzGvRdl4HF9lNWiWwbGou/8huNYl8xfN35fg8fVC8lNBSGKG 9yUFSRc+bwpCmiROjqFot5CRXDcwinRTCfWvyDrJ1PuhiMnyo1bgNqnSUMk+rG8ca/ZRzU6d8s/mE osmjA58+XEj9hHMuruLNCtn7GxkRnB5Iu9bdZFDaih6HQ4zas9EgJBav4CMdC14I7+/d8dTeXZDi9 UXNDk8Ag==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jj76Z-0003Ui-UY; Wed, 10 Jun 2020 20:13:47 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 18/51] mm: Support THPs in zero_user_segments Date: Wed, 10 Jun 2020 13:13:12 -0700 Message-Id: <20200610201345.13273-19-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200610201345.13273-1-willy@infradead.org> References: <20200610201345.13273-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: "Matthew Wilcox (Oracle)" We can only kmap() one subpage of a THP at a time, so loop over all relevant subpages, skipping ones which don't need to be zeroed. This is too large to inline when THPs are enabled and we actually need highmem, so put it in highmem.c. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/highmem.h | 11 ++++++-- mm/highmem.c | 62 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 68 insertions(+), 5 deletions(-) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index d6e82e3de027..f05589513103 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -284,13 +284,17 @@ static inline void clear_highpage(struct page *page) kunmap_atomic(kaddr); } +#if defined(CONFIG_HIGHMEM) && defined(CONFIG_TRANSPARENT_HUGEPAGE) +void zero_user_segments(struct page *page, unsigned start1, unsigned end1, + unsigned start2, unsigned end2); +#else /* !HIGHMEM || !TRANSPARENT_HUGEPAGE */ static inline void zero_user_segments(struct page *page, - unsigned start1, unsigned end1, - unsigned start2, unsigned end2) + unsigned start1, unsigned end1, + unsigned start2, unsigned end2) { void *kaddr = kmap_atomic(page); - BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); + BUG_ON(end1 > thp_size(page) || end2 > thp_size(page)); if (end1 > start1) memset(kaddr + start1, 0, end1 - start1); @@ -301,6 +305,7 @@ static inline void zero_user_segments(struct page *page, kunmap_atomic(kaddr); flush_dcache_page(page); } +#endif /* !HIGHMEM || !TRANSPARENT_HUGEPAGE */ static inline void zero_user_segment(struct page *page, unsigned start, unsigned end) diff --git a/mm/highmem.c b/mm/highmem.c index 64d8dea47dd1..686cae2f1ba5 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -367,9 +367,67 @@ void kunmap_high(struct page *page) if (need_wakeup) wake_up(pkmap_map_wait); } - EXPORT_SYMBOL(kunmap_high); -#endif + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +void zero_user_segments(struct page *page, unsigned start1, unsigned end1, + unsigned start2, unsigned end2) +{ + unsigned int i; + + BUG_ON(end1 > thp_size(page) || end2 > thp_size(page)); + + for (i = 0; i < thp_nr_pages(page); i++) { + void *kaddr; + unsigned this_end; + + if (end1 == 0 && start2 >= PAGE_SIZE) { + start2 -= PAGE_SIZE; + end2 -= PAGE_SIZE; + continue; + } + + if (start1 >= PAGE_SIZE) { + start1 -= PAGE_SIZE; + end1 -= PAGE_SIZE; + if (start2) { + start2 -= PAGE_SIZE; + end2 -= PAGE_SIZE; + } + continue; + } + + kaddr = kmap_atomic(page + i); + + this_end = min_t(unsigned, end1, PAGE_SIZE); + if (end1 > start1) + memset(kaddr + start1, 0, this_end - start1); + end1 -= this_end; + start1 = 0; + + if (start2 >= PAGE_SIZE) { + start2 -= PAGE_SIZE; + end2 -= PAGE_SIZE; + } else { + this_end = min_t(unsigned, end2, PAGE_SIZE); + if (end2 > start2) + memset(kaddr + start2, 0, this_end - start2); + end2 -= this_end; + start2 = 0; + } + + kunmap_atomic(kaddr); + + if (!end1 && !end2) + break; + } + flush_dcache_page(page); + + BUG_ON((start1 | start2 | end1 | end2) != 0); +} +EXPORT_SYMBOL(zero_user_segments); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif /* CONFIG_HIGHMEM */ #if defined(HASHED_PAGE_VIRTUAL) -- 2.26.2