From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by kanga.kvack.org (Postfix) with ESMTP id 3B9CC6B40BE for ; Mon, 26 Nov 2018 02:04:06 -0500 (EST) Received: by mail-wr1-f69.google.com with SMTP id x3so15090039wru.22 for ; Sun, 25 Nov 2018 23:04:06 -0800 (PST) Received: from pegase1.c-s.fr (pegase1.c-s.fr. [93.17.236.30]) by mx.google.com with ESMTPS id r7-v6si12197613wmb.2.2018.11.25.23.04.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 25 Nov 2018 23:04:04 -0800 (PST) Subject: Re: [PATCH 5/5] arch: simplify several early memory allocations References: <1543182277-8819-1-git-send-email-rppt@linux.ibm.com> <1543182277-8819-6-git-send-email-rppt@linux.ibm.com> From: Christophe LEROY Message-ID: <7a92357c-6251-fe84-d724-16fdc49d03a3@c-s.fr> Date: Mon, 26 Nov 2018 08:03:55 +0100 MIME-Version: 1.0 In-Reply-To: <1543182277-8819-6-git-send-email-rppt@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Mike Rapoport , linux-kernel@vger.kernel.org Cc: Michal Hocko , linux-sh@vger.kernel.org, linux-mm@kvack.org, Rich Felker , Paul Mackerras , sparclinux@vger.kernel.org, Vincent Chen , Jonas Bonn , linux-c6x-dev@linux-c6x.org, Yoshinori Sato , Russell King , Mark Salter , Arnd Bergmann , Stefan Kristiansson , openrisc@lists.librecores.org, Greentime Hu , Stafford Horne , Guan Xuetao , linux-arm-kernel@lists.infradead.org, Michal Simek , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Le 25/11/2018 à 22:44, Mike Rapoport a écrit : > There are several early memory allocations in arch/ code that use > memblock_phys_alloc() to allocate memory, convert the returned physical > address to the virtual address and then set the allocated memory to zero. > > Exactly the same behaviour can be achieved simply by calling > memblock_alloc(): it allocates the memory in the same way as > memblock_phys_alloc(), then it performs the phys_to_virt() conversion and > clears the allocated memory. > > Replace the longer sequence with a simpler call to memblock_alloc(). > > Signed-off-by: Mike Rapoport > --- > arch/arm/mm/mmu.c | 4 +--- > arch/c6x/mm/dma-coherent.c | 9 ++------- > arch/nds32/mm/init.c | 12 ++++-------- > arch/powerpc/kernel/setup-common.c | 4 ++-- > arch/powerpc/mm/pgtable_32.c | 4 +--- > arch/powerpc/mm/ppc_mmu_32.c | 3 +-- > arch/powerpc/platforms/powernv/opal.c | 3 +-- > arch/sparc/kernel/prom_64.c | 7 ++----- > arch/sparc/mm/init_64.c | 9 +++------ > arch/unicore32/mm/mmu.c | 4 +--- > 10 files changed, 18 insertions(+), 41 deletions(-) > [...] > diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c > index bda3c6f..9931e68 100644 > --- a/arch/powerpc/mm/pgtable_32.c > +++ b/arch/powerpc/mm/pgtable_32.c > @@ -50,9 +50,7 @@ __ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) > if (slab_is_available()) { > pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO); > } else { > - pte = __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE)); > - if (pte) > - clear_page(pte); > + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); memblock_alloc() uses memset to zeroize the block. clear_page() is more performant than memset(). Christophe [...]