| Subject | Re: [PATCHv2 04/28] mm: make remove_migration_ptes() beyond mm/migration.c | From | Dave Hansen <> | Date | Fri, 12 Feb 2016 08:54:58 -0800 |
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On 02/11/2016 06:21 AM, Kirill A. Shutemov wrote > We also shouldn't try to mlock() pte-mapped huge pages: pte-mapeed THP > pages are never mlocked.
That's kinda subtle. Can you explain more?
If we did the following:
ptr = mmap(NULL, 512*PAGE_SIZE, ...); mlock(ptr, 512*PAGE_SIZE); fork(); munmap(ptr + 100 * PAGE_SIZE, PAGE_SIZE);
I'd expect to get two processes, each mapping the same compound THP, one with a PMD and the other with 511 ptes and one hole. Is there something different that goes on?
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