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: Mon, 29 Jun 2020 18:59:20 +0300 Message-ID: <20200629155920.GD1492837@kernel.org> References: <20200627143453.31835-1-rppt@kernel.org> <20200627143453.31835-5-rppt@kernel.org> <20200627190304.GG25039@casper.infradead.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593446372; bh=O/nZ0BxK4nESVxMtlEZ3aR9HUzEjAJ3vpNzo90oK+Gw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ve2Rt8tVmffLLnlIRt4m0+FLkplbTh12wsmkxiiXh2shMIztHBj9/nk/f9S/ai5jU 3BFQpw5Dz/XZFCZs/y8ymsBDt+3vvNo/l/kVYqcYBemM5Bac+QbcUhusbQGI9QlPev vYsxGXmlFAgYBNiTAVuThytC5RkEIP2ptiiEd7Jg= Content-Disposition: inline In-Reply-To: <20200627190304.GG25039@casper.infradead.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane-mx.org@lists.ozlabs.org Sender: "Linuxppc-dev" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Matthew Wilcox Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , linux-mips@vger.kernel.org, Max Filippov , Satheesh Rajendran , linux-csky@vger.kernel.org, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, Stephen Rothwell , linux-hexagon@vger.kernel.org, Joerg Roedel , Mike Rapoport , Abdul Haleem , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Arnd Bergmann , linux-s390@vger.kernel.org, linux-um@lists.infradead.org, Steven Rostedt , linux-m68k@lists.linux-m68k.org, openrisc@lists.librecores.org, Andy Lutomirski , Stafford Horne , linux-arm-kernel@lists.infradead.org, linux-pari 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 also never set PageTable flag for early page tables and for the page tables allocated directly with get_free_page(), e.g PTI, KASAN. > 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? -- Sincerely yours, Mike.