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,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 081A1C2BBFD for ; Sat, 11 Apr 2020 07:20:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6A64216FD for ; Sat, 11 Apr 2020 07:20:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725959AbgDKHU5 (ORCPT ); Sat, 11 Apr 2020 03:20:57 -0400 Received: from verein.lst.de ([213.95.11.211]:52955 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbgDKHU4 (ORCPT ); Sat, 11 Apr 2020 03:20:56 -0400 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 Cc: Sergey Senozhatsky , Peter Zijlstra , Christoph Hellwig , Andrew Morton , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , x86@kernel.org, David Airlie , Daniel Vetter , Laura Abbott , Sumit Semwal , Sakari Ailus , Nitin Gupta , Robin Murphy , Christophe Leroy , linuxppc-dev@lists.ozlabs.org, linux-hyperv@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org 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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200410231136.GA101325@google.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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) From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc Date: Sat, 11 Apr 2020 09:20:52 +0200 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-Type: text/plain; charset=us-ascii Return-path: Received: from verein.lst.de ([213.95.11.211]:52955 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbgDKHU4 (ORCPT ); Sat, 11 Apr 2020 03:20:56 -0400 Content-Disposition: inline In-Reply-To: <20200410231136.GA101325@google.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Minchan Kim Cc: Sergey Senozhatsky , Peter Zijlstra , Christoph Hellwig , Andrew Morton , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , x86@kernel.org, David Airlie , Daniel Vetter , Laura Abbott , Sumit Semwal , Sakari Ailus , Nitin Gupta , Robin Murphy , Christophe Leroy , linuxppc-dev@lists.ozlabs.org, linux-hyperv@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org 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) 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,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 0676DC2BA2B for ; Sat, 11 Apr 2020 07:22:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 54D322078E for ; Sat, 11 Apr 2020 07:22:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54D322078E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48zmYW225wzDr74 for ; Sat, 11 Apr 2020 17:22:39 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48zmWf1fQvzDqxs for ; Sat, 11 Apr 2020 17:20:59 +1000 (AEST) 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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200410231136.GA101325@google.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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, Robin Murphy , linux-kernel@vger.kernel.org, Sergey Senozhatsky , iommu@lists.linux-foundation.org, Sakari Ailus , Andrew Morton , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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) 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 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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 D3B84C2BA2B for ; Sat, 11 Apr 2020 07:21:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 A696E2078E for ; Sat, 11 Apr 2020 07:21:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NFKECyPv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A696E2078E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OQzzpBassRGBIhgvyEaiFk3rzrJG0llTxCc87fEnfaI=; b=NFKECyPvQHSitS FNyq5QQJGmmkbvWbwtzjXVEZkiO9/fUkPSyihRfxyrpWy4bwf1NCO8ZltIKpPbkSYBbzf0sCM4lxi cGpVCDSyauXlMa2Icl2PzLGMKfbBXd0koF/yU22F7NTpAATkNtly5opLvvSNNLvBMRpjRAPXBLcx4 UEAQTUo+YeURkY4L80Uqn6Cha4/Hd0UfAurhbnM5xpW1W36sLn8Qt4NEa8rFtM5mxO8ampXcFPpdQ 2fM2wNjClyY9TmOyIVBAQvvybioH6EuYfRrb3zfDd2ecC9MsDDStwsdusphDzBOQmRLt3ejkXwMo8 RpNzspN7JIdGb4ljEFmQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jNARr-0004P7-CQ; Sat, 11 Apr 2020 07:21:03 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jNARn-0004O6-M9 for linux-arm-kernel@lists.infradead.org; Sat, 11 Apr 2020 07:21:01 +0000 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) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200411_002059_868115_95CFF02C X-CRM114-Status: UNSURE ( 9.41 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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, Sakari Ailus , Andrew Morton , linuxppc-dev@lists.ozlabs.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel