Now that Hyper-V overrides the sched_clock save/restore hooks if and only
sched_clock itself is set to the Hyper-V timer, drop the invocation of the
"old" save/restore callbacks. When the registration of the PV sched_clock
was done separate from overriding the save/restore hooks, it was possible
for Hyper-V to clobber the TSC save/restore callbacks without actually
switching to the Hyper-V timer.
Enabling a PV sched_clock is a one-way street, i.e. the kernel will never
revert to using TSC for sched_clock, and so there is no need to invoke the
TSC save/restore hooks (and if there was, it belongs in common PV code).
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
drivers/clocksource/hyperv_timer.c | 10 ----------
1 file changed, 10 deletions(-)
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 5a52d0acf31f..4a21874e91b9 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -524,9 +524,6 @@ static __always_inline void hv_setup_sched_clock(void *sched_clock)
}
#elif defined CONFIG_PARAVIRT
static u64 hv_ref_counter_at_suspend;
-static void (*old_save_sched_clock_state)(void);
-static void (*old_restore_sched_clock_state)(void);
-
/*
* Hyper-V clock counter resets during hibernation. Save and restore clock
* offset during suspend/resume, while also considering the time passed
@@ -536,8 +533,6 @@ static void (*old_restore_sched_clock_state)(void);
*/
static void hv_save_sched_clock_state(void)
{
- old_save_sched_clock_state();
-
hv_ref_counter_at_suspend = hv_read_reference_counter();
}
@@ -550,8 +545,6 @@ static void hv_restore_sched_clock_state(void)
* - reference counter (time) now.
*/
hv_sched_clock_offset -= (hv_ref_counter_at_suspend - hv_read_reference_counter());
-
- old_restore_sched_clock_state();
}
static __always_inline void hv_setup_sched_clock(void *sched_clock)
@@ -559,10 +552,7 @@ static __always_inline void hv_setup_sched_clock(void *sched_clock)
/* We're on x86/x64 *and* using PV ops */
paravirt_set_sched_clock(sched_clock);
- old_save_sched_clock_state = x86_platform.save_sched_clock_state;
x86_platform.save_sched_clock_state = hv_save_sched_clock_state;
-
- old_restore_sched_clock_state = x86_platform.restore_sched_clock_state;
x86_platform.restore_sched_clock_state = hv_restore_sched_clock_state;
}
#else /* !CONFIG_GENERIC_SCHED_CLOCK && !CONFIG_PARAVIRT */
--
2.48.1.711.g2feabab25a-goog
