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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 CC4D3C2BA2B for ; Sat, 11 Apr 2020 07:21:02 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 9817D2078E for ; Sat, 11 Apr 2020 07:21:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9817D2078E 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 hemlock.osuosl.org (Postfix) with ESMTP id 54BC8879A6; Sat, 11 Apr 2020 07:21:02 +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 nEIucA7MQS2h; Sat, 11 Apr 2020 07:21:01 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 1A9AB87987; Sat, 11 Apr 2020 07:21:01 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id F1257C1831; Sat, 11 Apr 2020 07:21:00 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4C75DC0177 for ; Sat, 11 Apr 2020 07:20:59 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 37512879A6 for ; Sat, 11 Apr 2020 07:20:59 +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 LnquiGWYJPg6 for ; Sat, 11 Apr 2020 07:20:57 +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 C065387987 for ; Sat, 11 Apr 2020 07:20:57 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 4505168BFE; Sat, 11 Apr 2020 09:20:52 +0200 (CEST) Date: Sat, 11 Apr 2020 09:20:52 +0200 From: Christoph Hellwig To: Minchan Kim Subject: Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc Message-ID: <20200411072052.GA31242@lst.de> References: <20200408115926.1467567-1-hch@lst.de> <20200408115926.1467567-11-hch@lst.de> <20200409160826.GC247701@google.com> <20200409165030.GG20713@hirez.programming.kicks-ass.net> <20200409170813.GD247701@google.com> <20200410023845.GA2354@jagdpanzerIV.localdomain> <20200410231136.GA101325@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200410231136.GA101325@google.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: linux-hyperv@vger.kernel.org, David Airlie , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, "K. Y. Srinivasan" , Sumit Semwal , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Wei Liu , Stephen Hemminger , x86@kernel.org, Christoph Hellwig , Peter Zijlstra , Laura Abbott , Nitin Gupta , Daniel Vetter , Haiyang Zhang , linaro-mm-sig@lists.linaro.org, bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Christophe Leroy , Robin Murphy , linux-kernel@vger.kernel.org, Sergey Senozhatsky , iommu@lists.linux-foundation.org, Andrew Morton , linuxppc-dev@lists.ozlabs.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" Hi Minchan, On Fri, Apr 10, 2020 at 04:11:36PM -0700, Minchan Kim wrote: > It doesn't mean we couldn't use zsmalloc as module any longer. It means > we couldn't use zsmalloc as module with pgtable mapping whcih was little > bit faster on microbenchmark in some architecutre(However, I usually temped > to remove it since it had several problems). However, we could still use > zsmalloc as module as copy way instead of pgtable mapping. Thus, if someone > really want to rollback the feature, they should provide reasonable reason > why it doesn't work for them. "A little fast" wouldn't be enough to exports > deep internal to the module. do you have any data how much faster it is on arm (and does that include arm64 as well)? Besides the exports which were my prime concern, zsmalloc with pgtable mappings also is the only user of map_kernel_range outside of vmalloc.c, if it really is another code base for tiny improvements we could mark map_kernel_range or in fact remove it entirely and open code it in the remaining callers. (unmap_kernel_range is a different story, it has a bunch of callers, and most look odd) _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu