Hi, Hyper-V TSC page clocksource is suitable for vDSO, however, the protocol defined by the hypervisor is different from VCLOCK_PVCLOCK. I implemented the required support re-using pvclock_page VVAR. Simple sysbench test shows the following results: Before: # time sysbench --test=memory --max-requests=500000 run ... real 1m22.618s user 0m50.193s sys 0m32.268s After: # time sysbench --test=memory --max-requests=500000 run ... real 0m50.218s user 0m50.171s sys 0m0.016s So it seems it is worth it. What do you think? Vitaly Kuznetsov (2): hyperv: implement hv_get_tsc_page() x86/vdso: Add VCLOCK_HVCLOCK vDSO clock read method arch/x86/entry/vdso/vclock_gettime.c | 48 ++++++++++++++++++++++++++++++++++++ arch/x86/entry/vdso/vma.c | 26 +++++++++++++------ arch/x86/hyperv/hv_init.c | 8 ++++++ arch/x86/include/asm/clocksource.h | 3 ++- arch/x86/include/asm/mshyperv.h | 8 ++++++ drivers/hv/Kconfig | 5 ++++ 6 files changed, 90 insertions(+), 8 deletions(-) -- 2.9.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
