Messages in this thread |  | | From | Wanpeng Li <> | Date | Fri, 22 Dec 2017 14:17:50 +0800 | Subject | Re: [PATCH v2] IPI performance benchmark |
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2017-12-22 3:02 GMT+08:00 Yury Norov <ynorov@caviumnetworks.com>: > On Wed, Dec 20, 2017 at 02:44:25PM +0800, Wanpeng Li wrote: >> Hi Yury, >> 2017-12-19 16:50 GMT+08:00 Yury Norov <ynorov@caviumnetworks.com>: >> > This benchmark sends many IPIs in different modes and measures >> > time for IPI delivery (first column), and total time, ie including >> > time to acknowledge the receive by sender (second column). >> > >> > The scenarios are: >> > Dry-run: do everything except actually sending IPI. Useful >> > to estimate system overhead. >> > Self-IPI: Send IPI to self CPU. >> > Normal IPI: Send IPI to some other CPU. >> > Broadcast IPI: Send broadcast IPI to all online CPUs. >> > Broadcast lock: Send broadcast IPI to all online CPUs and force them >> > acquire/release spinlock. >> > >> > The raw output looks like this: >> > [ 155.363374] Dry-run: 0, 2999696 ns >> > [ 155.429162] Self-IPI: 30385328, 65589392 ns >> > [ 156.060821] Normal IPI: 566914128, 631453008 ns >> > [ 158.384427] Broadcast IPI: 0, 2323368720 ns >> > [ 160.831850] Broadcast lock: 0, 2447000544 ns >> > >> > For virtualized guests, sending and reveiving IPIs causes guest exit. >> > I used this test to measure performance impact on KVM subsystem of >> > Christoffer Dall's series "Optimize KVM/ARM for VHE systems" [1]. >> > >> > Test machine is ThunderX2, 112 online CPUs. Below the results normalized >> > to host dry-run time, broadcast lock results omitted. Smaller - better. >> >> Could you test on a x86 box? I see a lot of calltraces on my haswell >> client host, there is no calltrace in the guest, however, I can still >> observe "Invalid parameters" warning when insmod this module. In >> addition, the x86 box fails to boot when ipi_benchmark is buildin. > > I tried to boot kernel with builtin test both on real hardware and > qemu+kvm - no calltraces or other problems. Kernel is 4.14, config for > host is attached. > > CPU is Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz > > Kernel is 4.14, config for host is attached, but it's default Ubuntu > config. Results and qemu command are below. Could you share more details > about your configuration?
Attch my config file.
Regards, Wanpeng Li
> > Yury > > qemu-system-x86_64 -hda debian_squeeze_amd64_standard.qcow2 \ > -smp 1 -curses --nographic --enable-kvm > > Host, 4 cores: > [ 0.237279] Dry-run: 0, 170292 ns > [ 0.643269] Self-IPI: 458516336, 922256372 ns > [ 0.902545] Self-IPI: 508518362, 972130665 ns > [ 0.646500] Broadcast IPI: 0, 97301545 ns > [ 0.649712] Broadcast lock: 0, 102364755 ns > > KVM, single core: > [ 0.237279] Dry-run: 0, 124500 ns > [ 0.643269] Self-IPI: 202518310, 405444790 ns > [ 0.643694] Normal IPI FAILED: -2 > [ 0.646500] Broadcast IPI: 0, 2524370 ns > [ 0.649712] Broadcast lock: 0, 2642270 ns > > KVM, 4 cores: > [ 0.492676] Dry-run: 0, 126380 ns > [ 0.902545] Self-IPI: 204085450, 409863800 ns > [ 2.179676] Normal IPI: 1058014940, 1276742820 ns > [ 3.396132] Broadcast IPI: 0, 1215934730 ns > [ 4.610719] Broadcast lock: 0, 1213945500 ns [unhandled content-type:application/octet-stream] |  |