From patchwork Thu Sep 22 16:39:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12985524 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 6A9CDC6FA95 for ; Thu, 22 Sep 2022 16:39:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232057AbiIVQjs (ORCPT ); Thu, 22 Sep 2022 12:39:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231625AbiIVQjo (ORCPT ); Thu, 22 Sep 2022 12:39:44 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2AC04C634; Thu, 22 Sep 2022 09:39:40 -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=5j6xtapvwUdhGQNeqeFIKOu/eta4czgVaM1iHN6JS40=; b=j0vqgm/DwRC8SWD3vRC35kKrKn uvfa2jRx/R29IzSGfeppQ2WS0arvUBbIfqu5Mbzep3uO08icfhEwzYXuMcyZJ6a9MbcDWKyM9ONge KnhFVA3Erg/CMa9dY3fHmXaXT40ijCcVrA0FGTQ7gskqRHdBGdOkAguEuSrZ/gCkRYOdHMFS6BCHp C82hZtdx5yNbWQnnYvFDBUS0FT9AN1oMnLoTYzUabH8HebiHHmkWw1VrhX46zKsdKwC69CfclGnG3 QwnTjPgVlg810r2MiXFKgPMZjvKoAtA1kHUc/ELqK/faE/mQAd4mZVFap16DC6VLzpevIorfii6eJ /1/Jr2rg==; 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 1obPEf-00862e-HK; Thu, 22 Sep 2022 10:39:38 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1obPEb-0001rs-As; Thu, 22 Sep 2022 10:39:33 -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 Cc: Christoph Hellwig , Greg Kroah-Hartman , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Ralph Campbell , Stephen Bates , Logan Gunthorpe Date: Thu, 22 Sep 2022 10:39:22 -0600 Message-Id: <20220922163926.7077-5-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220922163926.7077-1-logang@deltatee.com> References: <20220922163926.7077-1-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, hch@lst.de, gregkh@linuxfoundation.org, 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, 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, sbates@raithlin.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v10 4/8] lib/scatterlist: 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. Factor out the check for page mergability into a pages_are_mergable() helper and add a check with zone_device_pages_are_mergeable(). Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig --- lib/scatterlist.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/lib/scatterlist.c b/lib/scatterlist.c index c8c3d675845c..a0ad2a7959b5 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -410,6 +410,15 @@ static struct scatterlist *get_next_sg(struct sg_append_table *table, return new_sg; } +static bool pages_are_mergeable(struct page *a, struct page *b) +{ + if (page_to_pfn(a) != page_to_pfn(b) + 1) + return false; + if (!zone_device_pages_have_same_pgmap(a, b)) + return false; + return true; +} + /** * sg_alloc_append_table_from_pages - Allocate and initialize an append sg * table from an array of pages @@ -447,6 +456,7 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append, unsigned int chunks, cur_page, seg_len, i, prv_len = 0; unsigned int added_nents = 0; struct scatterlist *s = sgt_append->prv; + struct page *last_pg; /* * The algorithm below requires max_segment to be aligned to PAGE_SIZE @@ -460,21 +470,17 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append, return -EOPNOTSUPP; if (sgt_append->prv) { - unsigned long paddr = - (page_to_pfn(sg_page(sgt_append->prv)) * PAGE_SIZE + - sgt_append->prv->offset + sgt_append->prv->length) / - PAGE_SIZE; - if (WARN_ON(offset)) return -EINVAL; /* Merge contiguous pages into the last SG */ prv_len = sgt_append->prv->length; - while (n_pages && page_to_pfn(pages[0]) == paddr) { + last_pg = sg_page(sgt_append->prv); + while (n_pages && pages_are_mergeable(last_pg, pages[0])) { if (sgt_append->prv->length + PAGE_SIZE > max_segment) break; sgt_append->prv->length += PAGE_SIZE; - paddr++; + last_pg = pages[0]; pages++; n_pages--; } @@ -488,7 +494,7 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append, for (i = 1; i < n_pages; i++) { seg_len += PAGE_SIZE; if (seg_len >= max_segment || - page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) { + !pages_are_mergeable(pages[i], pages[i - 1])) { chunks++; seg_len = 0; } @@ -504,8 +510,7 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append, for (j = cur_page + 1; j < n_pages; j++) { seg_len += PAGE_SIZE; if (seg_len >= max_segment || - page_to_pfn(pages[j]) != - page_to_pfn(pages[j - 1]) + 1) + !pages_are_mergeable(pages[j], pages[j - 1])) break; }