On 10.05.24 04:22, Barry Song wrote:
Hi,
I'd like to propose a session about the allocation and reclamation of
mTHP. This is related to Yu Zhao's
TAO[1] but not the same.
OPPO has implemented mTHP-like large folios across thousands of
genuine Android devices, utilizing
ARM64 CONT-PTE. However, we've encountered challenges:
- The allocation of mTHP isn't consistently reliable; even after
prolonged use, obtaining large folios
remains uncertain.
As an instance, following a few hours of operation, the likelihood
of successfully allocating large
folios on a phone may decrease to just 2%.
- Mixing large and small folios in the same LRU list can lead to
mutual blocking and unpredictable
latency during reclamation/allocation.
For instance, if you require large folios, the LRU list's tail could
be filled with small folios.
LRU(LF- large folio, SF- small folio):
LF - LF - LF - SF - SF - SF - SF - SF - SF -SF - SF - SF - SF - SF - SF - SF
As we see more and more large folio users, with folios of differing
sizes, I do wonder if the problem will shift from an order-0 vs. order>0
to other orders. E.g., order-0 vs. order-4 vs. other orders.
Meaning: small vs. large folios will long term not be the real issue (in
some configurations it will remain that for sure).
What's your take on that?
--
Cheers,
David / dhildenb
