From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx134.postini.com [74.125.245.134]) by kanga.kvack.org (Postfix) with SMTP id 731256B0074 for ; Thu, 15 Aug 2013 16:43:50 -0400 (EDT) Date: Thu, 15 Aug 2013 13:43:48 -0700 From: Andrew Morton Subject: Re: [PATCH] memblock, numa: Binary search node id Message-Id: <20130815134348.bb119a7987af0bb64ed77b7b@linux-foundation.org> In-Reply-To: <1376545589-32129-1-git-send-email-yinghai@kernel.org> References: <1376545589-32129-1-git-send-email-yinghai@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Yinghai Lu Cc: Tejun Heo , Russ Anderson , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, 14 Aug 2013 22:46:29 -0700 Yinghai Lu wrote: > Current early_pfn_to_nid() on arch that support memblock go > over memblock.memory one by one, so will take too many try > near the end. > > We can use existing memblock_search to find the node id for > given pfn, that could save some time on bigger system that > have many entries memblock.memory array. Looks nice. I wonder how much difference it makes. > ... > > --- linux-2.6.orig/include/linux/memblock.h > +++ linux-2.6/include/linux/memblock.h > @@ -60,6 +60,8 @@ int memblock_reserve(phys_addr_t base, p > void memblock_trim_memory(phys_addr_t align); > > #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP > +int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn, > + unsigned long *end_pfn); > void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, > unsigned long *out_end_pfn, int *out_nid); > > Index: linux-2.6/mm/memblock.c > =================================================================== > --- linux-2.6.orig/mm/memblock.c > +++ linux-2.6/mm/memblock.c > @@ -914,6 +914,24 @@ int __init_memblock memblock_is_memory(p > return memblock_search(&memblock.memory, addr) != -1; > } > > +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP > +int __init_memblock memblock_search_pfn_nid(unsigned long pfn, > + unsigned long *start_pfn, unsigned long *end_pfn) > +{ > + struct memblock_type *type = &memblock.memory; > + int mid = memblock_search(type, (phys_addr_t)pfn << PAGE_SHIFT); > + > + if (mid == -1) > + return -1; > + > + *start_pfn = type->regions[mid].base >> PAGE_SHIFT; > + *end_pfn = (type->regions[mid].base + type->regions[mid].size) > + >> PAGE_SHIFT; > + > + return type->regions[mid].nid; > +} > +#endif This function will have no callers if CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID=y. That's not too bad as the function is __init_memblock. But this depends on CONFIG_ARCH_DISCARD_MEMBLOCK. Messy :( -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org