On 5/11/22 16:08, Minchan Kim wrote:
OK, so the code checks the wrong item each time. But the code really
only needs to know "is either _CMA or _ISOLATE set?". And so you
Yes.
can just sidestep the entire question by writing it like this:
int mt = get_pageblock_migratetype(page);
if (mt & (MIGRATE_ISOLATE | MIGRATE_CMA))
return false;
I am confused. Isn't it same question?
set_pageblock_migratetype(MIGRATE_ISOLATE)
if (get_pageblock_migrate(page) & MIGRATE_CMA)
set_pageblock_migratetype(MIGRATE_CMA)
if (get_pageblock_migrate(page) & MIGRATE_ISOLATE)
Well no, because the "&" operation is a single operation on the CPU, and
isn't going to get split up like that.
thanks,
--
John Hubbard
NVIDIA
