From patchwork Thu Apr 7 15:47:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12805553 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 C4F8EC433FE for ; Thu, 7 Apr 2022 17:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346196AbiDGR1H (ORCPT ); Thu, 7 Apr 2022 13:27:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346326AbiDGR06 (ORCPT ); Thu, 7 Apr 2022 13:26:58 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1B8CBF325; Thu, 7 Apr 2022 10:22:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=NhYwwPYUOPNVkjQIdyegnu/TVIl/nr3VeJZ7F4Q1rQY=; b=kW115vO/lD5rTsxYR5wDs4inqe b62XLPVR1SKPBKhjIMGvH8/MnKPRwidsE+zcAlS8tHsYa6gYUO/lWQKAiq0fskHTB4DfCzP9KwEt2 awuANPVzBGDxwiLlGKvFZcVBO0iijF1vKPmrj95MhayJpJlrS46NDTFfC+t7KI8DNk4ry1m5/8d1J +7oK34SQ8cIiJnBx3+JJHIyr3dMLRP4mSXQh6eF23EX5U4e3yvWW2GUbw6AGAk7S7lbdREAiI4Faf /F4ASkipN0tLk9wxIMmSs5rh/01GZKqdFrmMo+fMt2J66f3X0zQZYZqeS8UlYt9kYOkl7xUEiidL6 7kOVCESQ==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ncUMJ-002BBi-Mr; Thu, 07 Apr 2022 09:47:44 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1ncUME-00022A-Fc; Thu, 07 Apr 2022 09:47:38 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Ralph Campbell , Logan Gunthorpe Date: Thu, 7 Apr 2022 09:47:12 -0600 Message-Id: <20220407154717.7695-17-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220407154717.7695-1-logang@deltatee.com> References: <20220407154717.7695-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, jason@jlekstrand.net, dave.hansen@linux.intel.com, helgaas@kernel.org, dan.j.williams@intel.com, andrzej.jakowski@intel.com, dave.b.minturn@intel.com, jianxin.xiong@intel.com, ira.weiny@intel.com, robin.murphy@arm.com, martin.oliveira@eideticom.com, ckulkarnilinux@gmail.com, jhubbard@nvidia.com, rcampbell@nvidia.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v6 16/21] block: add check when merging zone device pages X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Consecutive zone device pages should not be merged into the same sgl or bvec segment with other types of pages or if they belong to different pgmaps. Otherwise getting the pgmap of a given segment is not possible without scanning the entire segment. This helper returns true either if both pages are not zone device pages or both pages are zone device pages with the same pgmap. Add a helper to determine if zone device pages are mergeable and use this helper in page_is_mergeable(). Signed-off-by: Logan Gunthorpe --- block/bio.c | 2 ++ include/linux/mm.h | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/block/bio.c b/block/bio.c index cdd7b2915c53..3406c0450db3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -834,6 +834,8 @@ static inline bool page_is_mergeable(const struct bio_vec *bv, return false; if (xen_domain() && !xen_biovec_phys_mergeable(bv, page)) return false; + if (!zone_device_pages_have_same_pgmap(bv->bv_page, page)) + return false; *same_page = ((vec_end_addr & PAGE_MASK) == page_addr); if (*same_page) diff --git a/include/linux/mm.h b/include/linux/mm.h index 14ef41af8b77..fb2264a17e4a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1108,6 +1108,24 @@ static inline bool is_zone_device_page(const struct page *page) { return page_zonenum(page) == ZONE_DEVICE; } + +/* + * Consecutive zone device pages should not be merged into the same sgl + * or bvec segment with other types of pages or if they belong to different + * pgmaps. Otherwise getting the pgmap of a given segment is not possible + * without scanning the entire segment. This helper returns true either if + * both pages are not zone device pages or both pages are zone device pages + * with the same pgmap. + */ +static inline bool zone_device_pages_have_same_pgmap(const struct page *a, + const struct page *b) +{ + if (is_zone_device_page(a) != is_zone_device_page(b)) + return false; + if (!is_zone_device_page(a)) + return true; + return a->pgmap == b->pgmap; +} extern void memmap_init_zone_device(struct zone *, unsigned long, unsigned long, struct dev_pagemap *); #else @@ -1115,6 +1133,11 @@ static inline bool is_zone_device_page(const struct page *page) { return false; } +static inline bool zone_device_pages_have_same_pgmap(const struct page *a, + const struct page *b) +{ + return true; +} #endif static inline bool folio_is_zone_device(const struct folio *folio)