From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Schwidefsky Subject: Re: [PATCH 1/2] mm,thp: refactor generic deposit/withdraw routines for wider usage Date: Thu, 11 Feb 2016 11:22:23 +0100 Message-ID: <20160211112223.0acc8237@mschwide> References: <1455182907-15445-1-git-send-email-vgupta@synopsys.com> <1455182907-15445-2-git-send-email-vgupta@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1455182907-15445-2-git-send-email-vgupta@synopsys.com> Sender: owner-linux-mm@kvack.org To: Vineet Gupta Cc: Andrew Morton , "Kirill A. Shutemov" , "Aneesh Kumar K.V" , "David S. Miller" , Alex Thorlton , Gerald Schaefer , linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, Andrea Arcangeli List-Id: linux-arch.vger.kernel.org On Thu, 11 Feb 2016 14:58:26 +0530 Vineet Gupta wrote: > Generic pgtable_trans_huge_deposit()/pgtable_trans_huge_withdraw() > assume pgtable_t to be struct page * which is not true for all arches. > Thus arc, s390, sparch end up with their own copies despite no special > hardware requirements (unlike powerpc). s390 does have a special hardware requirement. pgtable_t is an address for a 2K block of memory. It is *not* equivalent to a struct page * which refers to a 4K block of memory. That has been the whole point to introduce pgtable_t. > It seems massaging the code a bit can make it reusbale. Imho the new code for asm-generic looks fine, as long as the override with __HAVE_ARCH_PGTABLE_DEPOSIT/__HAVE_ARCH_PGTABLE_WITHDRAW continues to work I do not mind. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:58613 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750885AbcBKKWe (ORCPT ); Thu, 11 Feb 2016 05:22:34 -0500 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 11 Feb 2016 10:22:32 -0000 Date: Thu, 11 Feb 2016 11:22:23 +0100 From: Martin Schwidefsky Subject: Re: [PATCH 1/2] mm,thp: refactor generic deposit/withdraw routines for wider usage Message-ID: <20160211112223.0acc8237@mschwide> In-Reply-To: <1455182907-15445-2-git-send-email-vgupta@synopsys.com> References: <1455182907-15445-1-git-send-email-vgupta@synopsys.com> <1455182907-15445-2-git-send-email-vgupta@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Vineet Gupta Cc: Andrew Morton , "Kirill A. Shutemov" , "Aneesh Kumar K.V" , "David S. Miller" , Alex Thorlton , Gerald Schaefer , linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, Andrea Arcangeli Message-ID: <20160211102223.goQkduyjzSsT3zLqvW0kx-BnHM_aMT3TNxkUhBMm8l0@z> On Thu, 11 Feb 2016 14:58:26 +0530 Vineet Gupta wrote: > Generic pgtable_trans_huge_deposit()/pgtable_trans_huge_withdraw() > assume pgtable_t to be struct page * which is not true for all arches. > Thus arc, s390, sparch end up with their own copies despite no special > hardware requirements (unlike powerpc). s390 does have a special hardware requirement. pgtable_t is an address for a 2K block of memory. It is *not* equivalent to a struct page * which refers to a 4K block of memory. That has been the whole point to introduce pgtable_t. > It seems massaging the code a bit can make it reusbale. Imho the new code for asm-generic looks fine, as long as the override with __HAVE_ARCH_PGTABLE_DEPOSIT/__HAVE_ARCH_PGTABLE_WITHDRAW continues to work I do not mind. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.