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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 A4F9AC47247 for ; Fri, 1 May 2020 02:09:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FC55208CA for ; Fri, 1 May 2020 02:09:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728051AbgEACJZ (ORCPT ); Thu, 30 Apr 2020 22:09:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727889AbgEACJY (ORCPT ); Thu, 30 Apr 2020 22:09:24 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC428C035494; Thu, 30 Apr 2020 19:09:24 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL72-00FWOz-Ta; Fri, 01 May 2020 02:09:13 +0000 Date: Fri, 1 May 2020 03:09:12 +0100 From: Al Viro To: ira.weiny@intel.com Cc: linux-kernel@vger.kernel.org, Andrew Morton , Christian Koenig , Huang Rui , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Chris Zankel , Max Filippov , Dan Williams , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH V1 05/10] arch/kmap_atomic: Consolidate duplicate code Message-ID: <20200501020912.GD23230@ZenIV.linux.org.uk> References: <20200430203845.582900-1-ira.weiny@intel.com> <20200430203845.582900-6-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200430203845.582900-6-ira.weiny@intel.com> Sender: linux-csky-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org On Thu, Apr 30, 2020 at 01:38:40PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Every arch has the same code to ensure atomic operations and a check for > !HIGHMEM page. > > Remove the duplicate code by defining a core kmap_atomic() which only > calls the arch specific kmap_atomic_high() when the page is high memory. Err.... AFAICS, you've just silently changed the semantics for kmap_atomic_prot() here. And while most of the callers are converted, drivers/gpu/drm/ttm/ttm_bo_util.c one is not, so at the very least it's a bisect hazard... And I would argue that having kmap_atomic() differ from kmap_atomic_prot() wrt disabling preempt is asking for trouble. 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=-0.8 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 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 8ED2FC4724C for ; Fri, 1 May 2020 02:09:54 +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 5C9712073E for ; Fri, 1 May 2020 02:09:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QcrQWiQi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C9712073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-snps-arc-bounces+linux-snps-arc=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=Wv7DUtd6LmnlBlykEixyMJjvVZWFtQT9gdsO/JR8PHQ=; b=QcrQWiQiXmIQUB jvjLMsjHFSlFhyu/JCGu3ASDC8I9BvM7vSH/BLwk/s915ioQUiRd7G6bFdCsTC052b7eTKHvFV8ZH S9WeZzuzKd0Gvc5Xk9usyI3Fbpj4C3UCzmUud/yVwRxQKWix6igTAfEEWkO0U0BfLEjxuaTolmPtE WyzcxzaF4gFb1wFDopR2WeZdwH0o8C1+mxZYAI9qs5/qGED32Bjh3JSQUtb1N7nAXGQeQHhig2z7z cDSqDXbxQ98Viom+4imkksGJzJ0XymcGHllsJ1NkoWOHdjK7uqQHY1KYNA+0WX02IOPU/nPk3JHZ9 yNt5lFD1Ds0UmX66xYEA==; 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 1jUL7f-0000n5-QM; Fri, 01 May 2020 02:09:51 +0000 Received: from [2002:c35c:fd02::1] (helo=ZenIV.linux.org.uk) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL7c-0000mU-O2; Fri, 01 May 2020 02:09:50 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL72-00FWOz-Ta; Fri, 01 May 2020 02:09:13 +0000 Date: Fri, 1 May 2020 03:09:12 +0100 From: Al Viro To: ira.weiny@intel.com Subject: Re: [PATCH V1 05/10] arch/kmap_atomic: Consolidate duplicate code Message-ID: <20200501020912.GD23230@ZenIV.linux.org.uk> References: <20200430203845.582900-1-ira.weiny@intel.com> <20200430203845.582900-6-ira.weiny@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200430203845.582900-6-ira.weiny@intel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200430_190948_782608_7382257F X-CRM114-Status: UNSURE ( 7.93 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , Max Filippov , Huang Rui , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, Dan Williams , Helge Deller , x86@kernel.org, linux-csky@vger.kernel.org, Ingo Molnar , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Chris Zankel , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Koenig , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org On Thu, Apr 30, 2020 at 01:38:40PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Every arch has the same code to ensure atomic operations and a check for > !HIGHMEM page. > > Remove the duplicate code by defining a core kmap_atomic() which only > calls the arch specific kmap_atomic_high() when the page is high memory. Err.... AFAICS, you've just silently changed the semantics for kmap_atomic_prot() here. And while most of the callers are converted, drivers/gpu/drm/ttm/ttm_bo_util.c one is not, so at the very least it's a bisect hazard... And I would argue that having kmap_atomic() differ from kmap_atomic_prot() wrt disabling preempt is asking for trouble. _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc 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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 33DB6C47247 for ; Fri, 1 May 2020 02:12:33 +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 986102073E for ; Fri, 1 May 2020 02:12:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 986102073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49CwkP5PlqzDrFb for ; Fri, 1 May 2020 12:12:29 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=ftp.linux.org.uk (client-ip=2002:c35c:fd02::1; helo=zeniv.linux.org.uk; envelope-from=viro@ftp.linux.org.uk; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49CwgQ5dltzDr3y for ; Fri, 1 May 2020 12:09:54 +1000 (AEST) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL72-00FWOz-Ta; Fri, 01 May 2020 02:09:13 +0000 Date: Fri, 1 May 2020 03:09:12 +0100 From: Al Viro To: ira.weiny@intel.com Subject: Re: [PATCH V1 05/10] arch/kmap_atomic: Consolidate duplicate code Message-ID: <20200501020912.GD23230@ZenIV.linux.org.uk> References: <20200430203845.582900-1-ira.weiny@intel.com> <20200430203845.582900-6-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200430203845.582900-6-ira.weiny@intel.com> 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: Peter Zijlstra , Dave Hansen , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , Max Filippov , Huang Rui , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, Dan Williams , Helge Deller , x86@kernel.org, linux-csky@vger.kernel.org, Ingo Molnar , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Chris Zankel , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Koenig , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Apr 30, 2020 at 01:38:40PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Every arch has the same code to ensure atomic operations and a check for > !HIGHMEM page. > > Remove the duplicate code by defining a core kmap_atomic() which only > calls the arch specific kmap_atomic_high() when the page is high memory. Err.... AFAICS, you've just silently changed the semantics for kmap_atomic_prot() here. And while most of the callers are converted, drivers/gpu/drm/ttm/ttm_bo_util.c one is not, so at the very least it's a bisect hazard... And I would argue that having kmap_atomic() differ from kmap_atomic_prot() wrt disabling preempt is asking for trouble. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Date: Fri, 01 May 2020 02:09:12 +0000 Subject: Re: [PATCH V1 05/10] arch/kmap_atomic: Consolidate duplicate code Message-Id: <20200501020912.GD23230@ZenIV.linux.org.uk> List-Id: References: <20200430203845.582900-1-ira.weiny@intel.com> <20200430203845.582900-6-ira.weiny@intel.com> In-Reply-To: <20200430203845.582900-6-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ira.weiny@intel.com Cc: Peter Zijlstra , Dave Hansen , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , Max Filippov , Huang Rui , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, Dan Williams , Helge Deller , x86@kernel.org, linux-csky@vger.kernel.org, Ingo Molnar , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Chris Zankel , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Koenig , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" On Thu, Apr 30, 2020 at 01:38:40PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Every arch has the same code to ensure atomic operations and a check for > !HIGHMEM page. > > Remove the duplicate code by defining a core kmap_atomic() which only > calls the arch specific kmap_atomic_high() when the page is high memory. Err.... AFAICS, you've just silently changed the semantics for kmap_atomic_prot() here. And while most of the callers are converted, drivers/gpu/drm/ttm/ttm_bo_util.c one is not, so at the very least it's a bisect hazard... And I would argue that having kmap_atomic() differ from kmap_atomic_prot() wrt disabling preempt is asking for trouble. 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=-0.8 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 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 F2EDBC47247 for ; Fri, 1 May 2020 02:09:55 +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 C3B8F2073E for ; Fri, 1 May 2020 02:09:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="IiU+fH8q" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3B8F2073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk 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=6bSyZPCdOFjRxmvAvmdse2F33M34N/UGXj2Zq3td7OI=; b=IiU+fH8q/JJA3C jFu2IK4S4eoLpj7Wv4KoTBzhniYBllHHD3bsDBu7ilkWYl9AAgV0vEwmjaEbw58zKL+vklsCRHLMe qS0L+M2C8NVnOnI42BICBS6hZNRct2tPuRaem33NxYjzuNnB5eMHMwVT0VuO+lReQ3V7C2PHdFrmC InxhO1X3y1o4bvPNYSTDE3BE/mJI/TDyrBlRvnEoHsk8iyDcZ2p6bBjxQx3FFs8Upp7vZPWT9lVQq 3/RoPY3Qtld4zTYv1qlLaeod3zAnAsmhww8wD9COxarigMyO8L/GviNy/QA8V7idQ+lfU0BCD23jH nzHLJyzes2fGyioZ0rYw==; 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 1jUL7g-0000nF-8N; Fri, 01 May 2020 02:09:52 +0000 Received: from [2002:c35c:fd02::1] (helo=ZenIV.linux.org.uk) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL7c-0000mU-O2; Fri, 01 May 2020 02:09:50 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL72-00FWOz-Ta; Fri, 01 May 2020 02:09:13 +0000 Date: Fri, 1 May 2020 03:09:12 +0100 From: Al Viro To: ira.weiny@intel.com Subject: Re: [PATCH V1 05/10] arch/kmap_atomic: Consolidate duplicate code Message-ID: <20200501020912.GD23230@ZenIV.linux.org.uk> References: <20200430203845.582900-1-ira.weiny@intel.com> <20200430203845.582900-6-ira.weiny@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200430203845.582900-6-ira.weiny@intel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200430_190948_782608_7382257F X-CRM114-Status: UNSURE ( 7.93 ) 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: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , Max Filippov , Huang Rui , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, Dan Williams , Helge Deller , x86@kernel.org, linux-csky@vger.kernel.org, Ingo Molnar , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Chris Zankel , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Koenig , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" 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 On Thu, Apr 30, 2020 at 01:38:40PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Every arch has the same code to ensure atomic operations and a check for > !HIGHMEM page. > > Remove the duplicate code by defining a core kmap_atomic() which only > calls the arch specific kmap_atomic_high() when the page is high memory. Err.... AFAICS, you've just silently changed the semantics for kmap_atomic_prot() here. And while most of the callers are converted, drivers/gpu/drm/ttm/ttm_bo_util.c one is not, so at the very least it's a bisect hazard... And I would argue that having kmap_atomic() differ from kmap_atomic_prot() wrt disabling preempt is asking for trouble. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D99A2C47254 for ; Fri, 1 May 2020 07:24:04 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 AB807208C3 for ; Fri, 1 May 2020 07:24:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB807208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0FF526EC17; Fri, 1 May 2020 07:23:45 +0000 (UTC) Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 93C4B6E28E for ; Fri, 1 May 2020 02:24:48 +0000 (UTC) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUL72-00FWOz-Ta; Fri, 01 May 2020 02:09:13 +0000 Date: Fri, 1 May 2020 03:09:12 +0100 From: Al Viro To: ira.weiny@intel.com Subject: Re: [PATCH V1 05/10] arch/kmap_atomic: Consolidate duplicate code Message-ID: <20200501020912.GD23230@ZenIV.linux.org.uk> References: <20200430203845.582900-1-ira.weiny@intel.com> <20200430203845.582900-6-ira.weiny@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200430203845.582900-6-ira.weiny@intel.com> X-Mailman-Approved-At: Fri, 01 May 2020 07:22:25 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Dave Hansen , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , Max Filippov , Huang Rui , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, Dan Williams , Helge Deller , x86@kernel.org, linux-csky@vger.kernel.org, Ingo Molnar , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Chris Zankel , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Koenig , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Apr 30, 2020 at 01:38:40PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Every arch has the same code to ensure atomic operations and a check for > !HIGHMEM page. > > Remove the duplicate code by defining a core kmap_atomic() which only > calls the arch specific kmap_atomic_high() when the page is high memory. Err.... AFAICS, you've just silently changed the semantics for kmap_atomic_prot() here. And while most of the callers are converted, drivers/gpu/drm/ttm/ttm_bo_util.c one is not, so at the very least it's a bisect hazard... And I would argue that having kmap_atomic() differ from kmap_atomic_prot() wrt disabling preempt is asking for trouble. _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel