59 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			59 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From patchwork Tue Mar 13 22:42:40 2018
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| Content-Type: text/plain; charset="utf-8"
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| MIME-Version: 1.0
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| Content-Transfer-Encoding: 7bit
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| Subject: mm/page_alloc: fix boot hang in memmap_init_zone
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| From: Daniel Vacek <neelx@redhat.com>
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| X-Patchwork-Id: 10281093
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| Message-Id: <20180313224240.25295-1-neelx@redhat.com>
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| To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
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| Cc: Sudeep Holla <sudeep.holla@arm.com>,
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|  Naresh Kamboju <naresh.kamboju@linaro.org>,
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|  Daniel Vacek <neelx@redhat.com>, Andrew Morton <akpm@linux-foundation.org>,
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|  Mel Gorman <mgorman@techsingularity.net>, Michal Hocko <mhocko@suse.com>,
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|  Paul Burton <paul.burton@imgtec.com>,
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|  Pavel Tatashin <pasha.tatashin@oracle.com>,
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|  Vlastimil Babka <vbabka@suse.cz>, stable@vger.kernel.org
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| Date: Tue, 13 Mar 2018 23:42:40 +0100
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| 
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| On some architectures (reported on arm64) commit 864b75f9d6b01 ("mm/page_alloc: fix memmap_init_zone pageblock alignment")
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| causes a boot hang. This patch fixes the hang making sure the alignment
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| never steps back.
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| 
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| Link: http://lkml.kernel.org/r/0485727b2e82da7efbce5f6ba42524b429d0391a.1520011945.git.neelx@redhat.com
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| Fixes: 864b75f9d6b01 ("mm/page_alloc: fix memmap_init_zone pageblock alignment")
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| Signed-off-by: Daniel Vacek <neelx@redhat.com>
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| Tested-by: Sudeep Holla <sudeep.holla@arm.com>
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| Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
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| Cc: Andrew Morton <akpm@linux-foundation.org>
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| Cc: Mel Gorman <mgorman@techsingularity.net>
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| Cc: Michal Hocko <mhocko@suse.com>
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| Cc: Paul Burton <paul.burton@imgtec.com>
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| Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
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| Cc: Vlastimil Babka <vbabka@suse.cz>
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| Cc: <stable@vger.kernel.org>
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| ---
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|  mm/page_alloc.c | 7 ++++++-
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|  1 file changed, 6 insertions(+), 1 deletion(-)
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| 
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| diff --git a/mm/page_alloc.c b/mm/page_alloc.c
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| index 3d974cb2a1a1..e033a6895c6f 100644
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| --- a/mm/page_alloc.c
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| +++ b/mm/page_alloc.c
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| @@ -5364,9 +5364,14 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
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|  			 * is not. move_freepages_block() can shift ahead of
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|  			 * the valid region but still depends on correct page
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|  			 * metadata.
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| +			 * Also make sure we never step back.
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|  			 */
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| -			pfn = (memblock_next_valid_pfn(pfn, end_pfn) &
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| +			unsigned long next_pfn;
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| +
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| +			next_pfn = (memblock_next_valid_pfn(pfn, end_pfn) &
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|  					~(pageblock_nr_pages-1)) - 1;
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| +			if (next_pfn > pfn)
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| +				pfn = next_pfn;
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|  #endif
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|  			continue;
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|  		}
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