From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Rapoport Subject: Re: [PATCH 4/8] asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one() Date: Sun, 28 Jun 2020 10:10:44 +0300 Message-ID: <20200628071044.GC576120@kernel.org> References: <20200627143453.31835-1-rppt@kernel.org> <20200627143453.31835-5-rppt@kernel.org> <20200627190304.GG25039@casper.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200627190304.GG25039@casper.infradead.org> Sender: linux-kernel-owner@vger.kernel.org To: Matthew Wilcox Cc: linux-kernel@vger.kernel.org, Abdul Haleem , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Christophe Leroy , Joerg Roedel , Max Filippov , Mike Rapoport , Peter Zijlstra , Satheesh Rajendran , Stafford Horne , Stephen Rothwell , Steven Rostedt , linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mi List-Id: linux-arch.vger.kernel.org On Sat, Jun 27, 2020 at 08:03:04PM +0100, Matthew Wilcox wrote: > On Sat, Jun 27, 2020 at 05:34:49PM +0300, Mike Rapoport wrote: > > More elaborate versions on arm64 and x86 account memory for the user page > > tables and call to pgtable_pmd_page_ctor() as the part of PMD page > > initialization. > > > > Move the arm64 version to include/asm-generic/pgalloc.h and use the generic > > version on several architectures. > > > > The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is > > not enabled, so there is no functional change for most architectures except > > of the addition of __GFP_ACCOUNT for allocation of user page tables. > > Thanks for including this line; it reminded me that we're not setting > the PageTable flag on the page, nor accounting it to the zone page stats. > Hope you don't mind me tagging a patch to do that on as 9/8. > > We could also do with a pud_page_[cd]tor and maybe even p4d/pgd versions. > But that brings me to the next question -- could/should some of this > be moved over to asm-generic/pgalloc.h? The ctor/dtor aren't called > from anywhere else, and there's value to reducing the total amount of > code in mm.h, but then there's also value to keeping all the ifdef > ARCH_ENABLE_SPLIT_PMD_PTLOCK code together too. So I'm a bit torn. > What do you think? There are arhcitectures that don't use asm-generic/pgalloc.h but rather have their own, sometimes completely different, versoins of these funcitons. I've tried adding linux/pgalloc.h, but I've ended up with contradicting need to include asm/pgalloc.h before the generic code for some architecures or after the generic code for others :) I think let's leave it in mm.h for now, maybe after several more cleaups we could do better. -- Sincerely yours, Mike. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:57228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725958AbgF1HK4 (ORCPT ); Sun, 28 Jun 2020 03:10:56 -0400 Date: Sun, 28 Jun 2020 10:10:44 +0300 From: Mike Rapoport Subject: Re: [PATCH 4/8] asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one() Message-ID: <20200628071044.GC576120@kernel.org> References: <20200627143453.31835-1-rppt@kernel.org> <20200627143453.31835-5-rppt@kernel.org> <20200627190304.GG25039@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200627190304.GG25039@casper.infradead.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Matthew Wilcox Cc: linux-kernel@vger.kernel.org, Abdul Haleem , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Christophe Leroy , Joerg Roedel , Max Filippov , Mike Rapoport , Peter Zijlstra , Satheesh Rajendran , Stafford Horne , Stephen Rothwell , Steven Rostedt , linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, linuxppc-dev@lists.ozlabs.org, openrisc@lists.librecores.org, sparclinux@vger.kernel.org Message-ID: <20200628071044.2taGetdL2v38KY-QLa-pUS0_6X5ZTyML8bQ1IprY4gc@z> On Sat, Jun 27, 2020 at 08:03:04PM +0100, Matthew Wilcox wrote: > On Sat, Jun 27, 2020 at 05:34:49PM +0300, Mike Rapoport wrote: > > More elaborate versions on arm64 and x86 account memory for the user page > > tables and call to pgtable_pmd_page_ctor() as the part of PMD page > > initialization. > > > > Move the arm64 version to include/asm-generic/pgalloc.h and use the generic > > version on several architectures. > > > > The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is > > not enabled, so there is no functional change for most architectures except > > of the addition of __GFP_ACCOUNT for allocation of user page tables. > > Thanks for including this line; it reminded me that we're not setting > the PageTable flag on the page, nor accounting it to the zone page stats. > Hope you don't mind me tagging a patch to do that on as 9/8. > > We could also do with a pud_page_[cd]tor and maybe even p4d/pgd versions. > But that brings me to the next question -- could/should some of this > be moved over to asm-generic/pgalloc.h? The ctor/dtor aren't called > from anywhere else, and there's value to reducing the total amount of > code in mm.h, but then there's also value to keeping all the ifdef > ARCH_ENABLE_SPLIT_PMD_PTLOCK code together too. So I'm a bit torn. > What do you think? There are arhcitectures that don't use asm-generic/pgalloc.h but rather have their own, sometimes completely different, versoins of these funcitons. I've tried adding linux/pgalloc.h, but I've ended up with contradicting need to include asm/pgalloc.h before the generic code for some architecures or after the generic code for others :) I think let's leave it in mm.h for now, maybe after several more cleaups we could do better. -- Sincerely yours, Mike.