diff options
| author | Dexuan Cui <decui@microsoft.com> | 2023-04-09 00:03:39 +0300 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2023-04-17 22:19:05 +0300 |
| commit | c0e96acf884a1ce91c9bdd692c6a425b83c90285 (patch) | |
| tree | 02216621dc40f08f0e1cd0b26ecbd79e229054fc /drivers/clocksource | |
| parent | 2c6ba4216844ca7918289b49ed5f3f7138ee2402 (diff) | |
| download | linux-c0e96acf884a1ce91c9bdd692c6a425b83c90285.tar.xz | |
clocksource: hyper-v: make sure Invariant-TSC is used if it is available
If Hyper-V TSC page is unavailable and Invariant-TSC is available,
currently hyperv_cs_msr (rather than Invariant-TSC) is used by default.
Use Invariant-TSC by default by downgrading hyperv_cs_msr.rating in
hv_init_tsc_clocksource(), if Invariant-TSC is available.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230408210339.15085-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/hyperv_timer.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index f32948c8a96f..bcd9042a0c9f 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -517,9 +517,6 @@ static bool __init hv_init_tsc_clocksource(void) { union hv_reference_tsc_msr tsc_msr; - if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) - return false; - /* * If Hyper-V offers TSC_INVARIANT, then the virtualized TSC correctly * handles frequency and offset changes due to live migration, @@ -536,6 +533,9 @@ static bool __init hv_init_tsc_clocksource(void) hyperv_cs_msr.rating = 250; } + if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) + return false; + hv_read_reference_counter = read_hv_clock_tsc; /* |