lkml.org 
[lkml]   [2022]   [Aug]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] intel_idle: avoid tracing MSR writes while idling
On Wed, Aug 24, 2022 at 04:42:11PM -0700, Peter Shier wrote:
> With commit bf5835bcdb963 ("intel_idle: Disable IBRS during long idle"),
> enabling wrmsr trace with CONFIG_LOCKDEP causes "suspicious
> rcu_dereference_check() usage" warning because do_trace_write_msr does not
> use trace_write_msr_rcuidle.
>
> Change intel_idle_ibrs to use native_wrmsr to avoid tracing
>
> Signed-off-by: Peter Shier <pshier@google.com>
> ---

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

> drivers/idle/intel_idle.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
> index 3e101719689a..df129c73786f 100644
> --- a/drivers/idle/intel_idle.c
> +++ b/drivers/idle/intel_idle.c
> @@ -187,12 +187,12 @@ static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev,
> int ret;
>
> if (smt_active)
> - wrmsrl(MSR_IA32_SPEC_CTRL, 0);
> + native_wrmsr(MSR_IA32_SPEC_CTRL, 0);
>
> ret = __intel_idle(dev, drv, index);
>
> if (smt_active)
> - wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
> + native_wrmsr(MSR_IA32_SPEC_CTRL, spec_ctrl);
>
> return ret;
> }
> --

\
 
 \ /
  Last update: 2022-08-25 10:41    [W:0.056 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site