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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 62F97C2D0EA for ; Wed, 8 Apr 2020 15:42:33 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 40E322072F for ; Wed, 8 Apr 2020 15:42:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 40E322072F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id ED76D85E51; Wed, 8 Apr 2020 15:42:32 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7vAHlSPnRyp0; Wed, 8 Apr 2020 15:42:31 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id A3CA085DCF; Wed, 8 Apr 2020 15:42:31 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 87032C1AE8; Wed, 8 Apr 2020 15:42:31 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 37BFAC0177 for ; Wed, 8 Apr 2020 15:42:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 27B1C8821F for ; Wed, 8 Apr 2020 15:42:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rNX5MPHmGeCT for ; Wed, 8 Apr 2020 15:42:29 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by hemlock.osuosl.org (Postfix) with ESMTPS id 0CC3586D41 for ; Wed, 8 Apr 2020 15:42:29 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 313AE68C4E; Wed, 8 Apr 2020 17:42:26 +0200 (CEST) Date: Wed, 8 Apr 2020 17:42:25 +0200 From: Christoph Hellwig To: Hillf Danton Subject: Re: [PATCH 04/28] dma-mapping: use vmap insted of reimplementing it Message-ID: <20200408154225.GA28676@lst.de> References: <20200408115926.1467567-1-hch@lst.de> <20200408131736.9532-1-hdanton@sina.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200408131736.9532-1-hdanton@sina.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: linux-mm@kvack.org, Andrew Morton , Christoph Hellwig , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Wed, Apr 08, 2020 at 09:17:36PM +0800, Hillf Danton wrote: > > @@ -62,24 +42,20 @@ void *dma_common_pages_remap(struct page **pages, size_t size, > > void *dma_common_contiguous_remap(struct page *page, size_t size, > > pgprot_t prot, const void *caller) > > { > > - int i; > > + int count = size >> PAGE_SHIFT; > > struct page **pages; > > - struct vm_struct *area; > > + void *vaddr; > > + int i; > > > > - pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); > > + pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL); > > Is it making sense to vmalloc pages as long as array size is bigger than > PAGE_SIZE? Maybe, maybe not. But it certainly doesn't fit this series. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 8 Apr 2020 17:42:25 +0200 From: Christoph Hellwig Subject: Re: [PATCH 04/28] dma-mapping: use vmap insted of reimplementing it Message-ID: <20200408154225.GA28676@lst.de> References: <20200408115926.1467567-1-hch@lst.de> <20200408131736.9532-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200408131736.9532-1-hdanton@sina.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Hillf Danton Cc: Christoph Hellwig , Andrew Morton , linux-mm@kvack.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org On Wed, Apr 08, 2020 at 09:17:36PM +0800, Hillf Danton wrote: > > @@ -62,24 +42,20 @@ void *dma_common_pages_remap(struct page **pages, size_t size, > > void *dma_common_contiguous_remap(struct page *page, size_t size, > > pgprot_t prot, const void *caller) > > { > > - int i; > > + int count = size >> PAGE_SHIFT; > > struct page **pages; > > - struct vm_struct *area; > > + void *vaddr; > > + int i; > > > > - pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); > > + pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL); > > Is it making sense to vmalloc pages as long as array size is bigger than > PAGE_SIZE? Maybe, maybe not. But it certainly doesn't fit this series.