Messages in this thread | | | Date | Mon, 17 Jun 2013 09:53:00 +0800 | From | Zhang Yanfei <> | Subject | Re: [PATCH] mm: Add unlikely for current_order test |
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Hi David,
On 06/17/2013 02:04 AM, David Rientjes wrote: > On Sat, 15 Jun 2013, Zhang Yanfei wrote: > >> From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> >> >> Since we have an unlikely for the "current_order >= pageblock_order / 2" >> test above, adding an unlikely for this "current_order >= pageblock_order" >> test seems more appropriate. >> > > I don't understand the justification at all, current_order being unlikely > greater than or equal to pageblock_order / 2 doesn't imply at all that > it's unlikely that current_order is greater than or equal to > pageblock_order. >
hmmm... I am confused. Since current_order is >= pageblock_order / 2 is unlikely, why current_order is >= pageblock_order isn't unlikely. Or there are other tips?
Actually, I am also a little confused about why current_order should be unlikely greater than or equal to pageblock_order / 2. When borrowing pages with other migrate_type, we always search from MAX_ORDER-1, which is greater or equal to pageblock_order.
-- Thanks. Zhang Yanfei
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