From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id CA4CE6B0033 for ; Tue, 10 Jan 2017 20:57:52 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id z128so323806635pfb.4 for ; Tue, 10 Jan 2017 17:57:52 -0800 (PST) Received: from EUR01-HE1-obe.outbound.protection.outlook.com (mail-he1eur01on0074.outbound.protection.outlook.com. [104.47.0.74]) by mx.google.com with ESMTPS id f17si4012180plj.199.2017.01.10.17.57.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 10 Jan 2017 17:57:51 -0800 (PST) Date: Wed, 11 Jan 2017 09:57:39 +0800 From: Dennis Chen Subject: Re: [PATCH v29 1/9] memblock: add memblock_cap_memory_range() Message-ID: <20170111015737.GA518@arm.com> References: <20161228043347.27358-1-takahiro.akashi@linaro.org> <20161228043525.27420-1-takahiro.akashi@linaro.org> <20170110111617.GB21598@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20170110111617.GB21598@arm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Will Deacon , AKASHI Takahiro Cc: catalin.marinas@arm.com, akpm@linux-foundation.org, james.morse@arm.com, geoff@infradead.org, bauerman@linux.vnet.ibm.com, dyoung@redhat.com, mark.rutland@arm.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, kuleshovmail@gmail.com, zijun_hu@htc.com, tj@kernel.orgnd@arm.com On Tue, Jan 10, 2017 at 11:16:18AM +0000, Will Deacon wrote: > [adding some more folks to cc] > > On Wed, Dec 28, 2016 at 01:35:25PM +0900, AKASHI Takahiro wrote: > > Add memblock_cap_memory_range() which will remove all the memblock regions > > except the memory range specified in the arguments. In addition, rework is > > done on memblock_mem_limit_remove_map() to re-implement it using > > memblock_cap_memory_range(). > > > > This function, like memblock_mem_limit_remove_map(), will not remove > > memblocks with MEMMAP_NOMAP attribute as they may be mapped and accessed > > later as "device memory." > > See the commit a571d4eb55d8 ("mm/memblock.c: add new infrastructure to > > address the mem limit issue"). > > > > This function is used, in a succeeding patch in the series of arm64 kdump > > suuport, to limit the range of usable memory, or System RAM, on crash dump > > kernel. > > (Please note that "mem=" parameter is of little use for this purpose.) > > > > Signed-off-by: AKASHI Takahiro > > Reviewed-by: Will Deacon > > Acked-by: Catalin Marinas > > Cc: linux-mm@kvack.org > > Cc: Andrew Morton > > --- > > include/linux/memblock.h | 1 + > > mm/memblock.c | 44 +++++++++++++++++++++++++++++--------------- > > 2 files changed, 30 insertions(+), 15 deletions(-) > > Whilst this patch looks fine to me, it would be nice if Dennis (author of > memblock_mem_limit_remove_map) or one of the mm chaps could provide an ack > before I merge it via arm64. > Will feel free to add Acked-by: Dennis Chen Thanks, Dennis > > Thanks, > > Will > > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > > index 5b759c9acf97..fbfcacc50c29 100644 > > --- a/include/linux/memblock.h > > +++ b/include/linux/memblock.h > > @@ -333,6 +333,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn); > > phys_addr_t memblock_start_of_DRAM(void); > > phys_addr_t memblock_end_of_DRAM(void); > > void memblock_enforce_memory_limit(phys_addr_t memory_limit); > > +void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size); > > void memblock_mem_limit_remove_map(phys_addr_t limit); > > bool memblock_is_memory(phys_addr_t addr); > > int memblock_is_map_memory(phys_addr_t addr); > > diff --git a/mm/memblock.c b/mm/memblock.c > > index 7608bc305936..fea1688fef60 100644 > > --- a/mm/memblock.c > > +++ b/mm/memblock.c > > @@ -1514,11 +1514,37 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) > > (phys_addr_t)ULLONG_MAX); > > } > > > > +void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size) > > +{ > > + int start_rgn, end_rgn; > > + int i, ret; > > + > > + if (!size) > > + return; > > + > > + ret = memblock_isolate_range(&memblock.memory, base, size, > > + &start_rgn, &end_rgn); > > + if (ret) > > + return; > > + > > + /* remove all the MAP regions */ > > + for (i = memblock.memory.cnt - 1; i >= end_rgn; i--) > > + if (!memblock_is_nomap(&memblock.memory.regions[i])) > > + memblock_remove_region(&memblock.memory, i); > > + > > + for (i = start_rgn - 1; i >= 0; i--) > > + if (!memblock_is_nomap(&memblock.memory.regions[i])) > > + memblock_remove_region(&memblock.memory, i); > > + > > + /* truncate the reserved regions */ > > + memblock_remove_range(&memblock.reserved, 0, base); > > + memblock_remove_range(&memblock.reserved, > > + base + size, (phys_addr_t)ULLONG_MAX); > > +} > > + > > void __init memblock_mem_limit_remove_map(phys_addr_t limit) > > { > > - struct memblock_type *type = &memblock.memory; > > phys_addr_t max_addr; > > - int i, ret, start_rgn, end_rgn; > > > > if (!limit) > > return; > > @@ -1529,19 +1555,7 @@ void __init memblock_mem_limit_remove_map(phys_addr_t limit) > > if (max_addr == (phys_addr_t)ULLONG_MAX) > > return; > > > > - ret = memblock_isolate_range(type, max_addr, (phys_addr_t)ULLONG_MAX, > > - &start_rgn, &end_rgn); > > - if (ret) > > - return; > > - > > - /* remove all the MAP regions above the limit */ > > - for (i = end_rgn - 1; i >= start_rgn; i--) { > > - if (!memblock_is_nomap(&type->regions[i])) > > - memblock_remove_region(type, i); > > - } > > - /* truncate the reserved regions */ > > - memblock_remove_range(&memblock.reserved, max_addr, > > - (phys_addr_t)ULLONG_MAX); > > + memblock_cap_memory_range(0, max_addr); > > } > > > > static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr) > > -- > > 2.11.0 > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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