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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C143FC6FD1D for ; Wed, 15 Mar 2023 05:16:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231487AbjCOFQ6 (ORCPT ); Wed, 15 Mar 2023 01:16:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231492AbjCOFPj (ORCPT ); Wed, 15 Mar 2023 01:15:39 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC2A63E612; Tue, 14 Mar 2023 22:15:02 -0700 (PDT) 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=PaqUJoSuStWz+a+eZ6H5Czv2RDkRGCSPMhY7d1rRpLQ=; b=vvhYyf+z+JwQ/j/pQJl+0gs8Cg Z7U9+n33E4ya8Rs6VKmmnqEH28jdQ4DqxJoZzM5mdflmtSMd+yi4QD5DY7G6MwTu/aY/fxbFfqpzA GNRHXJsPYag8wyB2MsDXq0FNR167SZ8hfIU8jfQYsAEEWY7xVUG2EUAiHGSR8zgrURZk0SBcC/tw3 /zcFkUw5x8LSpC4C5WwfSqdey12gZW0dngWQsr7691RQiTnLYh7PJh4w2M+kkStz9lDF4v7fY+LUA HFBny6CHlaD22KncUJZ6rWt/MD07tTSoYRCHZOIQywVMEC83Jj2z/yp/0ev2MTAuRFR9j6kKg88OI cmYZqZ9g==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pcJTO-00DYDm-Gh; Wed, 15 Mar 2023 05:14:50 +0000 From: "Matthew Wilcox (Oracle)" To: linux-arch@vger.kernel.org Cc: Yin Fengwei , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Matthew Wilcox Subject: [PATCH v4 33/36] filemap: Add filemap_map_folio_range() Date: Wed, 15 Mar 2023 05:14:41 +0000 Message-Id: <20230315051444.3229621-34-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230315051444.3229621-1-willy@infradead.org> References: <20230315051444.3229621-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org From: Yin Fengwei filemap_map_folio_range() maps partial/full folio. Comparing to original filemap_map_pages(), it updates refcount once per folio instead of per page and gets minor performance improvement for large folio. With a will-it-scale.page_fault3 like app (change file write fault testing to read fault testing. Trying to upstream it to will-it-scale at [1]), got 2% performance gain on a 48C/96T Cascade Lake test box with 96 processes running against xfs. [1]: https://github.com/antonblanchard/will-it-scale/pull/37 Signed-off-by: Yin Fengwei Signed-off-by: Matthew Wilcox (Oracle) --- mm/filemap.c | 98 +++++++++++++++++++++++++++++----------------------- 1 file changed, 54 insertions(+), 44 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index a34abfe8c654..6e2b0778db45 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2199,16 +2199,6 @@ unsigned filemap_get_folios(struct address_space *mapping, pgoff_t *start, } EXPORT_SYMBOL(filemap_get_folios); -static inline -bool folio_more_pages(struct folio *folio, pgoff_t index, pgoff_t max) -{ - if (!folio_test_large(folio) || folio_test_hugetlb(folio)) - return false; - if (index >= max) - return false; - return index < folio->index + folio_nr_pages(folio) - 1; -} - /** * filemap_get_folios_contig - Get a batch of contiguous folios * @mapping: The address_space to search @@ -3480,6 +3470,53 @@ static inline struct folio *next_map_page(struct address_space *mapping, mapping, xas, end_pgoff); } +/* + * Map page range [start_page, start_page + nr_pages) of folio. + * start_page is gotten from start by folio_page(folio, start) + */ +static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf, + struct folio *folio, unsigned long start, + unsigned long addr, unsigned int nr_pages) +{ + vm_fault_t ret = 0; + struct vm_area_struct *vma = vmf->vma; + struct file *file = vma->vm_file; + struct page *page = folio_page(folio, start); + unsigned int mmap_miss = READ_ONCE(file->f_ra.mmap_miss); + unsigned int ref_count = 0, count = 0; + + do { + if (PageHWPoison(page)) + continue; + + if (mmap_miss > 0) + mmap_miss--; + + /* + * NOTE: If there're PTE markers, we'll leave them to be + * handled in the specific fault path, and it'll prohibit the + * fault-around logic. + */ + if (!pte_none(*vmf->pte)) + continue; + + if (vmf->address == addr) + ret = VM_FAULT_NOPAGE; + + ref_count++; + do_set_pte(vmf, page, addr); + update_mmu_cache(vma, addr, vmf->pte); + } while (vmf->pte++, page++, addr += PAGE_SIZE, ++count < nr_pages); + + /* Restore the vmf->pte */ + vmf->pte -= nr_pages; + + folio_ref_add(folio, ref_count); + WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss); + + return ret; +} + vm_fault_t filemap_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff) { @@ -3490,9 +3527,9 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, unsigned long addr; XA_STATE(xas, &mapping->i_pages, start_pgoff); struct folio *folio; - struct page *page; unsigned int mmap_miss = READ_ONCE(file->f_ra.mmap_miss); vm_fault_t ret = 0; + int nr_pages = 0; rcu_read_lock(); folio = first_map_page(mapping, &xas, end_pgoff); @@ -3507,45 +3544,18 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, addr = vma->vm_start + ((start_pgoff - vma->vm_pgoff) << PAGE_SHIFT); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, addr, &vmf->ptl); do { -again: - page = folio_file_page(folio, xas.xa_index); - if (PageHWPoison(page)) - goto unlock; - - if (mmap_miss > 0) - mmap_miss--; + unsigned long end; addr += (xas.xa_index - last_pgoff) << PAGE_SHIFT; vmf->pte += xas.xa_index - last_pgoff; last_pgoff = xas.xa_index; + end = folio->index + folio_nr_pages(folio) - 1; + nr_pages = min(end, end_pgoff) - xas.xa_index + 1; - /* - * NOTE: If there're PTE markers, we'll leave them to be - * handled in the specific fault path, and it'll prohibit the - * fault-around logic. - */ - if (!pte_none(*vmf->pte)) - goto unlock; + ret |= filemap_map_folio_range(vmf, folio, + xas.xa_index - folio->index, addr, nr_pages); + xas.xa_index += nr_pages; - /* We're about to handle the fault */ - if (vmf->address == addr) - ret = VM_FAULT_NOPAGE; - - do_set_pte(vmf, page, addr); - /* no need to invalidate: a not-present page won't be cached */ - update_mmu_cache(vma, addr, vmf->pte); - if (folio_more_pages(folio, xas.xa_index, end_pgoff)) { - xas.xa_index++; - folio_ref_inc(folio); - goto again; - } - folio_unlock(folio); - continue; -unlock: - if (folio_more_pages(folio, xas.xa_index, end_pgoff)) { - xas.xa_index++; - goto again; - } folio_unlock(folio); folio_put(folio); } while ((folio = next_map_page(mapping, &xas, end_pgoff)) != NULL); -- 2.39.2