diff mbox series

[v3] x86/cpu: Add INTEL_LUNARLAKE_M to X86_BUG_MONITOR

Message ID a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown@intel.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series [v3] x86/cpu: Add INTEL_LUNARLAKE_M to X86_BUG_MONITOR | expand

Commit Message

Len Brown Nov. 13, 2024, 2:07 a.m. UTC 
From: Len Brown <len.brown@intel.com>

Under some conditions, MONITOR wakeups on Lunar Lake processors
can be lost, resulting in significant user-visible delays.

Add LunarLake to X86_BUG_MONITOR so that wake_up_idle_cpu()
always sends an IPI, avoiding this potential delay.

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219364

Cc: stable@vger.kernel.org # 6.11
Signed-off-by: Len Brown <len.brown@intel.com>
---
v3 syntax tweak
v2 leave smp_kick_mwait_play_dead() alone

 arch/x86/kernel/cpu/intel.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Rafael J. Wysocki Nov. 13, 2024, 9:05 a.m. UTC | #1 
On Wed, Nov 13, 2024 at 3:07 AM Len Brown <lenb@kernel.org> wrote:
>
> From: Len Brown <len.brown@intel.com>
>
> Under some conditions, MONITOR wakeups on Lunar Lake processors
> can be lost, resulting in significant user-visible delays.
>
> Add LunarLake to X86_BUG_MONITOR so that wake_up_idle_cpu()
> always sends an IPI, avoiding this potential delay.
>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219364
>
> Cc: stable@vger.kernel.org # 6.11
> Signed-off-by: Len Brown <len.brown@intel.com>

Still

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
> v3 syntax tweak
> v2 leave smp_kick_mwait_play_dead() alone
>
>  arch/x86/kernel/cpu/intel.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index e7656cbef68d..4b5f3d052151 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -586,7 +586,9 @@ static void init_intel(struct cpuinfo_x86 *c)
>              c->x86_vfm == INTEL_WESTMERE_EX))
>                 set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
>
> -       if (boot_cpu_has(X86_FEATURE_MWAIT) && c->x86_vfm == INTEL_ATOM_GOLDMONT)
> +       if (boot_cpu_has(X86_FEATURE_MWAIT) &&
> +           (c->x86_vfm == INTEL_ATOM_GOLDMONT ||
> +            c->x86_vfm == INTEL_LUNARLAKE_M))
>                 set_cpu_bug(c, X86_BUG_MONITOR);
>
>  #ifdef CONFIG_X86_64
> --
> 2.43.0
>
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index e7656cbef68d..4b5f3d052151 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -586,7 +586,9 @@  static void init_intel(struct cpuinfo_x86 *c)
 	     c->x86_vfm == INTEL_WESTMERE_EX))
 		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
 
-	if (boot_cpu_has(X86_FEATURE_MWAIT) && c->x86_vfm == INTEL_ATOM_GOLDMONT)
+	if (boot_cpu_has(X86_FEATURE_MWAIT) &&
+	    (c->x86_vfm == INTEL_ATOM_GOLDMONT ||
+	     c->x86_vfm == INTEL_LUNARLAKE_M))
 		set_cpu_bug(c, X86_BUG_MONITOR);
 
 #ifdef CONFIG_X86_64