On 09/12/15 04:28, Paul Mackerras wrote: > On Wed, Nov 04, 2015 at 10:03:48AM +0100, Thomas Huth wrote: >> Only using 32 memslots for KVM on powerpc is way too low, you can >> nowadays hit this limit quite fast by adding a couple of PCI devices >> and/or pluggable memory DIMMs to the guest. >> x86 already increased the limit to 512 in total, to satisfy 256 >> pluggable DIMM slots, 3 private slots and 253 slots for other things >> like PCI devices. On powerpc, we only have 32 pluggable DIMMs in > > I agree with increasing the limit. Is there a reason we have only 32 > pluggable DIMMs in QEMU on powerpc, not more? Should we be increasing > that limit too? If so, maybe we should increase the number of memory > slots to 512?
Hmmmm ... the comment before the #define in QEMU reads: /* * This defines the maximum number of DIMM slots we can have for sPAPR * guest. This is not defined by sPAPR but we are defining it to 32 slots * based on default number of slots provided by PowerPC kernel. */ #define SPAPR_MAX_RAM_SLOTS 32 So as far as I can see, there's indeed a possibility that we'll increase this value once the kernel can handle more slots! So I guess you're right and we should play save and use more slots right from the start. I'll send a new patch with 512 instead. >> QEMU, not 256, so we likely do not as much slots as on x86. Thus > > "so we likely do not need as many slots as on x86" would be better > English. Oops, I'm sure that was my original intention ... anyway, thanks for pointing it out, it's always good to get some feedback as a non-native English speaker. Thomas -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
