From nobody Mon Feb 9 16:45:40 2026 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 1A31EEB64DA for ; Mon, 10 Jul 2023 20:46:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232969AbjGJUqC (ORCPT ); Mon, 10 Jul 2023 16:46:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230200AbjGJUo6 (ORCPT ); Mon, 10 Jul 2023 16:44:58 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32278E7A; Mon, 10 Jul 2023 13:43:48 -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=3MITzrjsscz3EOfHnUvCpgkBiqSORw5f6CrRiwc69RA=; b=c4AwRiQVrDhrNfG53FzdnE3K+f r0ZI918ORvWE+/rlklI90tC0rTzLt/bZqIrIPosed6W8sSGZxn5juLhXXar5zemsZK9Vcqxkkq584 hDoHHqbFMo7S/5Kft9b2sm/K+b4TNB+bz5U1evgEm9J9ZpskVhypF9jwxVDDkfidplEasdsIZjYqO hH7enTDz4wEm9cPzJr4rkEdVKpTkoNXBC4520HuxwPXnYULE3dtoqo3/DlkNRUpSSrtJge5TyrO3P 66GSziBTrEilNJlA1FCPqBoUjxKyXL04BGstWBXnLIjizU1uhiKJbsmRFrSuJbkOfbXM/ZC6jW7yK Q5ywJ05w==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qIxjV-00Eurk-IK; Mon, 10 Jul 2023 20:43:45 +0000 From: "Matthew Wilcox (Oracle)" To: Andrew Morton Cc: Yin Fengwei , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Matthew Wilcox Subject: [PATCH v5 37/38] filemap: Batch PTE mappings Date: Mon, 10 Jul 2023 21:43:38 +0100 Message-Id: <20230710204339.3554919-38-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230710204339.3554919-1-willy@infradead.org> References: <20230710204339.3554919-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Yin Fengwei Call set_pte_range() once per contiguous range of the folio instead of once per page. This batches the updates to mm counters and the rmap. 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 15% performance gain on a 48C/96T Cascade Lake test box with 96 processes running against xfs. Perf data collected before/after the change: 18.73%--page_add_file_rmap | --11.60%--__mod_lruvec_page_state | |--7.40%--__mod_memcg_lruvec_state | | | --5.58%--cgroup_rstat_updated | --2.53%--__mod_lruvec_state | --1.48%--__mod_node_page_state 9.93%--page_add_file_rmap_range | --2.67%--__mod_lruvec_page_state | |--1.95%--__mod_memcg_lruvec_state | | | --1.57%--cgroup_rstat_updated | --0.61%--__mod_lruvec_state | --0.54%--__mod_node_page_state The running time of __mode_lruvec_page_state() is reduced about 9%. [1]: https://github.com/antonblanchard/will-it-scale/pull/37 Signed-off-by: Yin Fengwei Signed-off-by: Matthew Wilcox (Oracle) --- mm/filemap.c | 43 +++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index c06e9d331416..014b73eb96a1 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3480,11 +3480,12 @@ static vm_fault_t filemap_map_folio_range(struct vm= _fault *vmf, struct file *file =3D vma->vm_file; struct page *page =3D folio_page(folio, start); unsigned int mmap_miss =3D READ_ONCE(file->f_ra.mmap_miss); - unsigned int ref_count =3D 0, count =3D 0; + unsigned int count =3D 0; + pte_t *old_ptep =3D vmf->pte; =20 do { - if (PageHWPoison(page)) - continue; + if (PageHWPoison(page + count)) + goto skip; =20 if (mmap_miss > 0) mmap_miss--; @@ -3494,20 +3495,34 @@ static vm_fault_t filemap_map_folio_range(struct vm= _fault *vmf, * handled in the specific fault path, and it'll prohibit the * fault-around logic. */ - if (!pte_none(*vmf->pte)) - continue; - - if (vmf->address =3D=3D addr) - ret =3D VM_FAULT_NOPAGE; + if (!pte_none(vmf->pte[count])) + goto skip; =20 - ref_count++; - set_pte_range(vmf, folio, page, 1, addr); - } while (vmf->pte++, page++, addr +=3D PAGE_SIZE, ++count < nr_pages); + count++; + continue; +skip: + if (count) { + set_pte_range(vmf, folio, page, count, addr); + folio_ref_add(folio, count); + if (in_range(vmf->address, addr, count)) + ret =3D VM_FAULT_NOPAGE; + } =20 - /* Restore the vmf->pte */ - vmf->pte -=3D nr_pages; + count++; + page +=3D count; + vmf->pte +=3D count; + addr +=3D count * PAGE_SIZE; + count =3D 0; + } while (--nr_pages > 0); + + if (count) { + set_pte_range(vmf, folio, page, count, addr); + folio_ref_add(folio, count); + if (in_range(vmf->address, addr, count)) + ret =3D VM_FAULT_NOPAGE; + } =20 - folio_ref_add(folio, ref_count); + vmf->pte =3D old_ptep; WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss); =20 return ret; --=20 2.39.2