On 7/23/20 8:20 AM, Paul Mackerras wrote: > On Mon, Jun 08, 2020 at 01:57:14PM +0200, Cédric Le Goater wrote: >> POWER8 and POWER9 have 12-bit LPIDs. Change LPID_RSVD to support up to >> (4096 - 2) guests on these processors. POWER7 is kept the same with a >> limitation of (1024 - 2), but it might be time to drop KVM support for >> POWER7. >> >> Tested with 2048 guests * 4 vCPUs on a witherspoon system with 512G >> RAM and a bit of swap. >> >> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx> > > Thanks, patch applied to my kvm-ppc-next branch. We have pushed the limits further on a 1TB system and reached the limit of 4094 guests with 16 vCPUs. With more vCPUs, the system starts to check-stop. We believe that the pages used by the interrupt controller for the backing store of the XIVE internal tables (END and NVT) allocated with GFP_KERNEL are reclaimable. I am thinking of changing the allocation flags with : __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC because XIVE should be able to fail gracefully if the system is low on mem. Is that correct ? Thanks, C.
