Cédric Le Goater <c...@kaod.org> writes: > On 04/07/2017 08:07 AM, Cédric Le Goater wrote: >> On 04/07/2017 07:24 AM, Nikunj A Dadhania wrote: >>> Cédric Le Goater <c...@kaod.org> writes: >>> >>>> Hello Nikunj, >>>> >>>> On 04/06/2017 12:22 PM, Nikunj A Dadhania wrote: >>>>> The series enables Multi-Threaded TCG on PPC64 >>>>> >>>>> Patch 01: Use atomic_cmpxchg in store conditional >>>>> 02: Handle first write to page during atomic operation >>>>> 03: Generate memory barriers for sync/isync and load/store >>>>> conditional >>>>> >>>>> Patches are based on ppc-for-2.10 >>>>> >>>>> Tested using following: >>>>> ./ppc64-softmmu/qemu-system-ppc64 -cpu POWER8 -vga none -nographic >>>>> -machine pseries,usb=off -m 2G -smp 8,cores=8,threads=1 -accel >>>>> tcg,thread=multi f23.img >>>> >>>> I tried it with a Ubuntu 16.04.2 guest using stress --cpu 8. It looked >>>> good : the CPU usage of QEMU reached 760% on the host. >>> >>> Cool. >>> >>>>> Todo: >>>>> * Enable other machine types and PPC32. >>>> >>>> I am quite ignorant on the topic. >>>> Have you looked at what it would take to emulate support of the HW >>>> threads ? >>> >>> We would need to implement msgsndp (doorbell support for IPI between >>> threads of same core) >> >> ok. I get it. Thanks, >> >>>> and the PowerNV machine ? >>> >>> Haven't tried it, should work. Just give a shot, let me know if you see >>> problems. >> >> sure. pnv is still on 2.9, so I will rebase on 2.10, merge your >> patches and tell you. > > The system seems to be spinning in skiboot in cpu_idle/relax when > starting the linux kernel. It finally boots, but it is rather long. > David has merged enough to test if you want to give it a try.
Does PPC have Wait-for-irq or similar "sleeping" instructions? We had to ensure we were not jumping out of the cpu loop and suspend normally. See c22edfebff29f63d793032e4fbd42a035bb73e27 for an example. -- Alex Bennée
