linux-hyperv.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 0/2] clocksource/Hyper-V: Add Hyper-V specific sched clock function
@ 2019-07-29  7:52 lantianyu1986
  2019-07-29  7:52 ` [PATCH 1/2] clocksource/Hyper-v: Allocate Hyper-V tsc page statically lantianyu1986
                   ` (2 more replies)
  0 siblings, 3 replies; 14+ messages in thread
From: lantianyu1986 @ 2019-07-29  7:52 UTC (permalink / raw)
  To: luto, tglx, mingo, bp, hpa, x86, kys, haiyangz, sthemmin, sashal,
	daniel.lezcano, arnd, michael.h.kelley, ashal
  Cc: Tianyu Lan, linux-arch, linux-hyperv, linux-kernel

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

Hyper-V guests use the default native_sched_clock() in pv_ops.time.sched_clock
on x86.  But native_sched_clock() directly uses the raw TSC value, which
can be discontinuous in a Hyper-V VM.   Add the generic hv_setup_sched_clock()
to set the sched clock function appropriately.  On x86, this sets
pv_ops.time.sched_clock to read the Hyper-V reference TSC value that is
scaled and adjusted to be continuous.

Also move the Hyper-V reference TSC initialization much earlier in the boot
process so no discontinuity is observed when pv_ops.time.sched_clock
calculates its offset.  This earlier initialization requires that the Hyper-V TSC
page be allocated statically instead of with vmalloc(), so fixup the references
to the TSC page and the method of getting its physical address.

Tianyu Lan (2):
  clocksource/Hyper-v: Allocate Hyper-V tsc page statically
  clocksource/Hyper-V: Add Hyper-V specific sched clock function

 arch/x86/entry/vdso/vma.c          |  2 +-
 arch/x86/hyperv/hv_init.c          |  2 --
 arch/x86/kernel/cpu/mshyperv.c     |  8 ++++++++
 drivers/clocksource/hyperv_timer.c | 34 ++++++++++++++++------------------
 include/asm-generic/mshyperv.h     |  1 +
 5 files changed, 26 insertions(+), 21 deletions(-)

-- 
2.14.5


^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2019-08-21  8:54 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-29  7:52 [PATCH 0/2] clocksource/Hyper-V: Add Hyper-V specific sched clock function lantianyu1986
2019-07-29  7:52 ` [PATCH 1/2] clocksource/Hyper-v: Allocate Hyper-V tsc page statically lantianyu1986
2019-08-12 18:39   ` Michael Kelley
2019-07-29  7:52 ` [PATCH 2/2] clocksource/Hyper-V: Add Hyper-V specific sched clock function lantianyu1986
2019-08-12 18:41   ` Michael Kelley
2019-07-29 10:59 ` [PATCH 0/2] " Vitaly Kuznetsov
2019-07-29 11:09   ` Peter Zijlstra
2019-07-29 12:13     ` Vitaly Kuznetsov
2019-07-30 13:41       ` Tianyu Lan
2019-08-12 19:22         ` Michael Kelley
2019-08-13  8:33           ` Vitaly Kuznetsov
2019-08-20 14:32             ` Michael Kelley
2019-08-21  7:15               ` Vitaly Kuznetsov
2019-08-21  8:54                 ` Vitaly Kuznetsov

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).