Concurrent page-fault handling with per-VMA locks

Posted Sep 6, 2022 16:35 UTC (Tue) by Wol (subscriber, #4433)
In reply to: Concurrent page-fault handling with per-VMA locks by calumapplepie
Parent article: Concurrent page-fault handling with per-VMA locks

> Hmm, good point... the downside would be memory consumption. 64-bit sequence numbers would increase the size of every vma_struct by about 5% (by my estimate of scanning the code).

Could you make the sequence number include the pid?

What are the chances of a 16-bit rolling number concatenated with the low order 16-bit pid as your sequence number colliding?

Cheers,
Wol

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Concurrent page-fault handling with per-VMA locks

Posted Sep 6, 2022 20:42 UTC (Tue) by WolfWings (subscriber, #56790) [Link] (1 responses)

...hasn't the PID been quite a bit larger than 16-bit for some time now? Just software limited to only use 16-bit PIDs by default for compatibility?

Concurrent page-fault handling with per-VMA locks

Posted Sep 7, 2022 6:24 UTC (Wed) by Wol (subscriber, #4433) [Link]

I know. Which is why I said use the low-order 16 bits ...

Cheers,
Wol