From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 2653D6B0261 for ; Mon, 12 Dec 2016 04:54:41 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id q10so234690390pgq.7 for ; Mon, 12 Dec 2016 01:54:41 -0800 (PST) Received: from szxga02-in.huawei.com (szxga02-in.huawei.com. [119.145.14.65]) by mx.google.com with ESMTP id s136si42708199pgc.65.2016.12.12.01.54.39 for ; Mon, 12 Dec 2016 01:54:40 -0800 (PST) Subject: Re: [PATCH] arm64: mm: Fix NOMAP page initialization References: <1481307042-29773-1-git-send-email-rrichter@cavium.com> <83d6e6d0-cfb3-ec8b-241b-ec6a50dc2aa9@huawei.com> From: Yisheng Xie Message-ID: <9168b603-04aa-4302-3197-00f17fb336bd@huawei.com> Date: Mon, 12 Dec 2016 17:53:02 +0800 MIME-Version: 1.0 In-Reply-To: <83d6e6d0-cfb3-ec8b-241b-ec6a50dc2aa9@huawei.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Robert Richter , Russell King , Catalin Marinas , Will Deacon Cc: Ard Biesheuvel , David Daney , Mark Rutland , Hanjun Guo , James Morse , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hanjun Guo , Xishi Qiu hi Robert, On 2016/12/12 11:12, Yisheng Xie wrote: > hi Robert, > > On 2016/12/10 2:10, Robert Richter wrote: >> On ThunderX systems with certain memory configurations we see the >> following BUG_ON(): >> >> kernel BUG at mm/page_alloc.c:1848! >> >> This happens for some configs with 64k page size enabled. The BUG_ON() >> checks if start and end page of a memmap range belongs to the same >> zone. >> >> The BUG_ON() check fails if a memory zone contains NOMAP regions. In >> this case the node information of those pages is not initialized. This >> causes an inconsistency of the page links with wrong zone and node >> information for that pages. NOMAP pages from node 1 still point to the >> mem zone from node 0 and have the wrong nid assigned. >> > The patch can work for zone contains NOMAP regions. > > However, if BIOS do not add WB/WT/WC attribute to a physical address range, the > is_memory(md) will return false and this range will not be added to memblock. > efi_init > -> reserve_regions > if (is_memory(md)) { > early_init_dt_add_memory_arch(paddr, size); > > if (!is_usable_memory(md)) > memblock_mark_nomap(paddr, size); > } > > Then BUG_ON() check will also fails. Any idea about it? > It seems that memblock_is_memory() is also too strict for early_pfn_valid, so what about this patch, which use common pfn_valid as early_pfn_valid when CONFIG_HAVE_ARCH_PFN_VALID=y: ------------ diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 0f088f3..9d596f3 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1200,7 +1200,17 @@ static inline int pfn_present(unsigned long pfn) #define pfn_to_nid(pfn) (0) #endif +#ifdef CONFIG_HAVE_ARCH_PFN_VALID +static inline int early_pfn_valid(unsigned long pfn) +{ + if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) + return 0; + return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); +} +#define early_pfn_valid early_pfn_valid +#else #define early_pfn_valid(pfn) pfn_valid(pfn) +#endif void sparse_init(void); #else #define sparse_init() do {} while (0) -- 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