On 02/04/2016 07:02 AM, Joonsoo Kim wrote:
On Wed, Feb 03, 2016 at 06:50:11PM +0100, Vlastimil Babka wrote:Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime") has added the runtime gigantic page allocation via alloc_contig_range(), making this support available only when CONFIG_CMA is enabled. Because it doesn't depend on MIGRATE_CMA pageblocks and the associated infrastructure, it is possible with few simple adjustments to require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA. After this patch, alloc_contig_range() and related functions are available and used for gigantic pages with just CONFIG_MEMORY_ISOLATION enabled. Note CONFIG_CMA selects CONFIG_MEMORY_ISOLATION. This allows supporting runtime gigantic pages without the CMA-specific checks in page allocator fastpaths.You need to set CONFIG_COMPACTION or CONFIG_CMA to use isolate_migratepages_range() and others in alloc_contig_range().
Hm, right, thanks for catching this. I admit I didn't try disabling compaction during the tests.
Thanks.
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