[vfio-users] problem with hugepages and sound

[Okky Hendriansyah]

On November 5, 2015 at 10:49:32, Alex Williamson (alex.l.williamson at gmail.com) wrote:
The fragmentation issue with hugepages is generally that as memory gets fragmented, there's no guarantee that you can reliably allocate hugepages.  A script that doesn't do any error checking to test how many huge pages are actually available might work 99% of the time, but the 100th time you start that guest without a host system reboot, maybe it won't get all the pages you requested and starting the VM will fail.  That's the more significant benefit of boot time allocated hugepages I think, but you also lose the flexibility of having that memory available for general use otherwise, which is why transparent hugepages are so nice, but as I already mentioned, those don't work with page pinning for device assignment.
Thanks for your explanation, Alex. A 99% chance is more than enough for me. If that’s the case, OP’s way of creating hugepages should be enough and probably I’ll use that myself to have a more dynamic allocation for other uses (VirtualBox, etc.). 



Best regards,

-- 
Okky Hendriansyah

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