mbox series

[v2,00/13] local_clock() vs noinstr

Message ID 20230519102058.581557770@infradead.org
Headers show
Series local_clock() vs noinstr | expand

Message

Peter Zijlstra May 19, 2023, 10:20 a.m. UTC 
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(-)

Comments

Michael Kelley May 19, 2023, 6:38 p.m. UTC | #1 
From: Peter Zijlstra <peterz@infradead.org> Sent: Friday, May 19, 2023 3:21 AM
> 
> Currently hv_read_tsc_page_tsc() (ab)uses the (valid) time value of
> U64_MAX as an error return. This breaks the clean wrap-around of the
> clock.
> 
> Modify the function signature to return a boolean state and provide
> another u64 pointer to store the actual time on success. This obviates
> the need to steal one time value and restores the full counter width.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  arch/x86/include/asm/vdso/gettimeofday.h |   10 ++++++----
>  arch/x86/kvm/x86.c                       |    7 +++----
>  drivers/clocksource/hyperv_timer.c       |   16 +++++++++++-----
>  include/clocksource/hyperv_timer.h       |   24 +++++++++---------------
>  4 files changed, 29 insertions(+), 28 deletions(-)
> 

Reviewed-by: Michael Kelley <mikelley@microsoft.com>