RE: [PATCH v2 00/13] local_clock() vs noinstr

From: "Michael Kelley (LINUX)" <mikelley@microsoft.com>
To: Peter Zijlstra <peterz@infradead.org>,
	"bigeasy@linutronix.de" <bigeasy@linutronix.de>
Cc: Mark Rutland <Mark.Rutland@arm.com>,
	"maz@kernel.org" <maz@kernel.org>,
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Subject: RE: [PATCH v2 00/13] local_clock() vs noinstr
Date: Fri, 19 May 2023 18:48:20 +0000	[thread overview]
Message-ID: <BYAPR21MB16887E8B94335E4331FF439AD77CA@BYAPR21MB1688.namprd21.prod.outlook.com> (raw)
In-Reply-To: <20230519102058.581557770@infradead.org>

From: Peter Zijlstra <peterz@infradead.org> Sent: Friday, May 19, 2023 3:21 AM
> 
> Hi All,
> 
> latest version of the local_clock_noinstr() patches.
> 
> Most of the changes are in Hyper-V and x86/vdso/gettimeofday; Michael has been
> very helpful navigating the Hyper-V spec and fixing their sched_clock
> implementation.
> 
> ---
>  arch/arm64/include/asm/arch_timer.h      |  8 +----
>  arch/arm64/include/asm/io.h              | 12 +++----
>  arch/loongarch/include/asm/loongarch.h   |  2 +-
>  arch/loongarch/kernel/time.c             |  6 ++--
>  arch/s390/include/asm/timex.h            | 13 ++++---
>  arch/s390/kernel/time.c                  |  5 +++
>  arch/x86/include/asm/mshyperv.h          |  5 +++
>  arch/x86/include/asm/vdso/gettimeofday.h | 41 ++++++++++++++++------
>  arch/x86/kernel/kvmclock.c               |  4 +--
>  arch/x86/kernel/tsc.c                    | 38 +++++++++++++++-----
>  arch/x86/kvm/x86.c                       |  7 ++--
>  arch/x86/xen/time.c                      |  3 +-
>  drivers/clocksource/arm_arch_timer.c     | 60 ++++++++++++++++++++++++--------
>  drivers/clocksource/hyperv_timer.c       | 44 ++++++++++++++---------
>  drivers/cpuidle/cpuidle.c                |  8 ++---
>  drivers/cpuidle/poll_state.c             |  4 +--
>  include/clocksource/hyperv_timer.h       | 24 +++++--------
>  include/linux/math64.h                   |  2 +-
>  include/linux/rbtree_latch.h             |  2 +-
>  include/linux/sched/clock.h              | 17 ++++++++-
>  include/linux/seqlock.h                  | 15 ++++----
>  kernel/printk/printk.c                   |  2 +-
>  kernel/sched/clock.c                     | 19 ++++++----
>  kernel/time/sched_clock.c                | 24 +++++++++----
>  kernel/time/timekeeping.c                |  4 +--
>  25 files changed, 242 insertions(+), 127 deletions(-)

Based on linux-next20230519, tested the full series in a Hyper-V
VM on x86/x64.   Did mainly a basic smoke test.  Sched clock
appears to work correctly.  Verified correct operation of the TSC page
clocksource and the MSR-based clocksource.  Verified that vDSO
gettimeofday() works with the Hyper-V TSC page clocksource and
is correctly disabled with the Hyper-V MSR-based clocksource.
Tested in a normal VM and in an "SEV-SNP with vTOM" VM.

Tested-by: Michael Kelley <mikelley@microsoft.com>  # Hyper-V