From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753676AbdHKTCQ (ORCPT ); Fri, 11 Aug 2017 15:02:16 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:29527 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753605AbdHKTCO (ORCPT ); Fri, 11 Aug 2017 15:02:14 -0400 Subject: Re: [v6 04/15] mm: discard memblock data later To: Michal Hocko Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, ard.biesheuvel@linaro.org, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, Mel Gorman References: <1502138329-123460-1-git-send-email-pasha.tatashin@oracle.com> <1502138329-123460-5-git-send-email-pasha.tatashin@oracle.com> <20170811093249.GE30811@dhcp22.suse.cz> From: Pasha Tatashin Message-ID: <42a04441-47ad-2fa0-ca3c-784c717213f7@oracle.com> Date: Fri, 11 Aug 2017 15:00:47 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170811093249.GE30811@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michal, This suggestion won't work, because there are arches without memblock support: tile, sh... So, I would still need to have: #ifdef CONFIG_MEMBLOCK in page_alloc, or define memblock_discard() stubs in nobootmem headfile. In either case it would become messier than what it is right now. Pasha > I have just one nit below > Acked-by: Michal Hocko > > [...] >> diff --git a/mm/memblock.c b/mm/memblock.c >> index 2cb25fe4452c..bf14aea6ab70 100644 >> --- a/mm/memblock.c >> +++ b/mm/memblock.c >> @@ -285,31 +285,27 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u >> } >> >> #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK > > pull this ifdef inside memblock_discard and you do not have an another > one in page_alloc_init_late > > [...] >> +/** >> + * Discard memory and reserved arrays if they were allocated >> + */ >> +void __init memblock_discard(void) >> { > > here > >> - if (memblock.memory.regions == memblock_memory_init_regions) >> - return 0; >> + phys_addr_t addr, size; >> >> - *addr = __pa(memblock.memory.regions); >> + if (memblock.reserved.regions != memblock_reserved_init_regions) { >> + addr = __pa(memblock.reserved.regions); >> + size = PAGE_ALIGN(sizeof(struct memblock_region) * >> + memblock.reserved.max); >> + __memblock_free_late(addr, size); >> + } >> >> - return PAGE_ALIGN(sizeof(struct memblock_region) * >> - memblock.memory.max); >> + if (memblock.memory.regions == memblock_memory_init_regions) { >> + addr = __pa(memblock.memory.regions); >> + size = PAGE_ALIGN(sizeof(struct memblock_region) * >> + memblock.memory.max); >> + __memblock_free_late(addr, size); >> + } >> } >> - >> #endif