From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f70.google.com (mail-pl0-f70.google.com [209.85.160.70]) by kanga.kvack.org (Postfix) with ESMTP id B58366B21C4 for ; Tue, 21 Aug 2018 21:39:06 -0400 (EDT) Received: by mail-pl0-f70.google.com with SMTP id k5-v6so218632pls.7 for ; Tue, 21 Aug 2018 18:39:06 -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 81-v6sor111679pfo.63.2018.08.21.18.39.05 for (Google Transport Security); Tue, 21 Aug 2018 18:39:05 -0700 (PDT) Subject: Re: [RESEND PATCH v10 3/6] mm: page_alloc: reduce unnecessary binary search in memblock_next_valid_pfn() References: <1530867675-9018-1-git-send-email-hejianet@gmail.com> <1530867675-9018-4-git-send-email-hejianet@gmail.com> <61ca29b9-a985-cce0-03e9-d216791c802c@microsoft.com> <334337ca-811e-4a2e-09ff-65ebe37ef6df@gmail.com> <20180821140829.7d804678e9db8725f52180c2@linux-foundation.org> From: Jia He Message-ID: <5b9ed490-9e17-70ac-6b03-7ae5c6ea7b87@gmail.com> Date: Wed, 22 Aug 2018 09:38:51 +0800 MIME-Version: 1.0 In-Reply-To: <20180821140829.7d804678e9db8725f52180c2@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Pasha Tatashin , Russell King , Catalin Marinas , Will Deacon , Mark Rutland , Ard Biesheuvel , Michal Hocko , Wei Yang , Kees Cook , Laura Abbott , Vladimir Murzin , Philip Derrin , AKASHI Takahiro , James Morse , Steve Capper , Pavel Tatashin , Gioh Kim , Vlastimil Babka , Mel Gorman , Johannes Weiner , Kemi Wang , Petr Tesarik , YASUAKI ISHIMATSU , Andrey Ryabinin , Nikolay Borisov , Daniel Jordan , Daniel Vacek , Eugeniu Rosca , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Jia He Hi Andrew On 8/22/2018 5:08 AM, Andrew Morton Wrote: > On Tue, 21 Aug 2018 14:14:30 +0800 Jia He wrote: > >> Hi Pasha >> >> On 8/17/2018 9:08 AM, Pasha Tatashin Wrote: >>> >>>> Signed-off-by: Jia He >>>> --- >>>> mm/memblock.c | 37 +++++++++++++++++++++++++++++-------- >>>> 1 file changed, 29 insertions(+), 8 deletions(-) >>>> >>>> diff --git a/mm/memblock.c b/mm/memblock.c >>>> index ccad225..84f7fa7 100644 >>>> --- a/mm/memblock.c >>>> +++ b/mm/memblock.c >>>> @@ -1140,31 +1140,52 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size, >>>> #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ >>>> >>>> #ifdef CONFIG_HAVE_MEMBLOCK_PFN_VALID >>>> +static int early_region_idx __init_memblock = -1; >>> >>> One comment: >>> >>> This should be __initdata, but even better bring it inside the function >>> as local static variable. >>> >> Seems it should be __initdata_memblock instead of __initdata? >> > > Eh, it's 4 bytes. > > It should however be local to the sole function which uses it. Sorry, I am not clear for this comment^ early_region_idx records the *last* valid region idx in last memblock_next_valid_pfn. So it should be static instead of local variable? > > And what's this "ulong" thing? mm/ uses unsigned long. ok, will change it -- Cheers, Jia > > --- a/mm/memblock.c~mm-page_alloc-reduce-unnecessary-binary-search-in-memblock_next_valid_pfn-fix > +++ a/mm/memblock.c > @@ -1232,15 +1232,15 @@ int __init_memblock memblock_set_node(ph > #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ > > #ifdef CONFIG_HAVE_MEMBLOCK_PFN_VALID > -static int early_region_idx __init_memblock = -1; > -ulong __init_memblock memblock_next_valid_pfn(ulong pfn) > +unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn) > { > struct memblock_type *type = &memblock.memory; > struct memblock_region *regions = type->regions; > uint right = type->cnt; > uint mid, left = 0; > - ulong start_pfn, end_pfn, next_start_pfn; > + unsigned long start_pfn, end_pfn, next_start_pfn; > phys_addr_t addr = PFN_PHYS(++pfn); > + static int early_region_idx __initdata_memblock = -1; > > /* fast path, return pfn+1 if next pfn is in the same region */ > if (early_region_idx != -1) { > --- a/include/linux/mmzone.h~mm-page_alloc-reduce-unnecessary-binary-search-in-memblock_next_valid_pfn-fix > +++ a/include/linux/mmzone.h > @@ -1269,7 +1269,7 @@ static inline int pfn_present(unsigned l > > #define early_pfn_valid(pfn) pfn_valid(pfn) > #ifdef CONFIG_HAVE_MEMBLOCK_PFN_VALID > -extern ulong memblock_next_valid_pfn(ulong pfn); > +extern unsigned long memblock_next_valid_pfn(unsigned long pfn); > #define next_valid_pfn(pfn) memblock_next_valid_pfn(pfn) > #endif > void sparse_init(void); > _ > >