On 18.01.21 14:21, Anshuman Khandual wrote: > > > On 1/18/21 6:43 PM, Anshuman Khandual wrote: >> From: David Hildenbrand <david@xxxxxxxxxx> >> >> Right now, we only check against MAX_PHYSMEM_BITS - but turns out there >> are more restrictions of which memory we can actually hotplug, especially >> om arm64 or s390x once we support them: we might receive something like >> -E2BIG or -ERANGE from add_memory_driver_managed(), stopping device >> operation. >> >> So, check right when initializing the device which memory we can add, >> warning the user. Try only adding actually pluggable ranges: in the worst >> case, no memory provided by our device is pluggable. >> >> In the usual case, we expect all device memory to be pluggable, and in >> corner cases only some memory at the end of the device-managed memory >> region to not be pluggable. >> >> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> >> Cc: Jason Wang <jasowang@xxxxxxxxxx> >> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> >> Cc: Michal Hocko <mhocko@xxxxxxxxxx> >> Cc: Oscar Salvador <osalvador@xxxxxxx> >> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >> Cc: catalin.marinas@xxxxxxx >> Cc: teawater <teawaterz@xxxxxxxxxxxxxxxxx> >> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> >> Cc: Pankaj Gupta <pankaj.gupta@xxxxxxxxxxxxxxx> >> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> >> Cc: hca@xxxxxxxxxxxxx >> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> >> Cc: Will Deacon <will@xxxxxxxxxx> >> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> >> Cc: Mark Rutland <mark.rutland@xxxxxxx> >> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx> >> Cc: Michal Hocko <mhocko@xxxxxxxxxx> >> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> >> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > > Hello David, > > As your original patch was in the RFC state, I have just maintained > the same here as well. But once you test this patch along with the > new series, please do let me know if this needs to be converted to > a normal PATCH instead. Thank you. I'll give it a churn on x86-64, where not that much should change. It will be interesting to test with arm64 in such corner cases in the future. Thanks -- Thanks, David / dhildenb
