Messages in this thread | | | Date | Sun, 25 Jan 2015 22:42:56 +0800 | From | Zhang Yanfei <> | Subject | Re: [PATCH] mm: incorporate read-only pages into transparent huge pages |
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Hello
在 2015/1/25 17:25, Vlastimil Babka 写道: > On 23.1.2015 20:18, Andrea Arcangeli wrote: >>> >+ if (!pte_write(pteval)) { >>> >+ if (++ro > khugepaged_max_ptes_none) >>> >+ goto out_unmap; >>> >+ } >> It's true this is maxed out at 511, so there must be at least one >> writable and not none pte (as results of the two "ro" and "none" >> counters checks). > > Hm, but if we consider ro and pte_none separately, both can be lower > than 512, but the sum of the two can be 512, so we can actually be in > read-only VMA?
Yes, I also think so.
So is it necessary to add a at-least-one-writable-pte check just like the existing at-least-one-page-referenced check?
Thanks.
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