From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id 472996B0269 for ; Thu, 28 Jun 2018 22:31:00 -0400 (EDT) Received: by mail-qk0-f200.google.com with SMTP id f2-v6so8113211qkm.10 for ; Thu, 28 Jun 2018 19:31:00 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id o19-v6sor4651064qki.159.2018.06.28.19.30.59 for (Google Transport Security); Thu, 28 Jun 2018 19:30:59 -0700 (PDT) From: Jia He Subject: [PATCH v9 5/6] arm: arm64: introduce pfn_valid_region() Date: Fri, 29 Jun 2018 10:29:22 +0800 Message-Id: <1530239363-2356-6-git-send-email-hejianet@gmail.com> In-Reply-To: <1530239363-2356-1-git-send-email-hejianet@gmail.com> References: <1530239363-2356-1-git-send-email-hejianet@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Russell King , Andrew Morton , Michal Hocko , Catalin Marinas , Mel Gorman , Will Deacon , Mark Rutland , "H. Peter Anvin" Cc: Pavel Tatashin , Daniel Jordan , AKASHI Takahiro , Gioh Kim , Steven Sistare , Daniel Vacek , Eugeniu Rosca , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, James Morse , Ard Biesheuvel , Steve Capper , Thomas Gleixner , Ingo Molnar , Greg Kroah-Hartman , Kate Stewart , Philippe Ombredanne , Johannes Weiner , Kemi Wang , Petr Tesarik , YASUAKI ISHIMATSU , Andrey Ryabinin , Nikolay Borisov , richard.weiyang@gmail.com, Jia He , Jia He Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible") optimized the loop in memmap_init_zone(). But there is still some room for improvement. E.g. in early_pfn_valid(), we can record the last returned memblock region. If current pfn and last pfn are in the same memory region, we needn't do the unnecessary binary searches because memblock_is_nomap is the same result for whole memory region. Signed-off-by: Jia He --- include/linux/early_pfn.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/include/linux/early_pfn.h b/include/linux/early_pfn.h index f9e40c3..9609391 100644 --- a/include/linux/early_pfn.h +++ b/include/linux/early_pfn.h @@ -51,5 +51,29 @@ ulong __init_memblock memblock_next_valid_pfn(ulong pfn) return PHYS_PFN(regions[early_region_idx].base); } EXPORT_SYMBOL(memblock_next_valid_pfn); + +int pfn_valid_region(ulong pfn) +{ + ulong start_pfn, end_pfn; + struct memblock_type *type = &memblock.memory; + struct memblock_region *regions = type->regions; + + if (early_region_idx != -1) { + start_pfn = PFN_DOWN(regions[early_region_idx].base); + end_pfn = PFN_DOWN(regions[early_region_idx].base + + regions[early_region_idx].size); + + if (pfn >= start_pfn && pfn < end_pfn) + return !memblock_is_nomap( + ®ions[early_region_idx]); + } + + early_region_idx = memblock_search_pfn_regions(pfn); + if (early_region_idx == -1) + return false; + + return !memblock_is_nomap(®ions[early_region_idx]); +} +EXPORT_SYMBOL(pfn_valid_region); #endif /*CONFIG_HAVE_MEMBLOCK_PFN_VALID*/ #endif /*__EARLY_PFN_H*/ -- 1.8.3.1