Re: [PATCH 13/25] context_tracking: Introduce context_tracking_enabled_cpu()
On Wed, Nov 14, 2018 at 03:45:57AM +0100, Frederic Weisbecker wrote:
> This allows us to check if a remote CPU runs context tracking
> (ie: is nohz_full). We'll need that to reliably support "nice"
> accounting on kcpustat.
>
> Signed-off-by: Frederic Weisbecker
> Cc: Yauheni Kaliuta
> Cc: Thomas Gleixner
> Cc: Rik van Riel
> Cc: Peter Zijlstra
> Cc: Wanpeng Li
> Cc: Ingo Molnar
> ---
> include/linux/context_tracking_state.h | 6 ++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/context_tracking_state.h
> b/include/linux/context_tracking_state.h
> index 08f125f..5877177 100644
> --- a/include/linux/context_tracking_state.h
> +++ b/include/linux/context_tracking_state.h
> @@ -31,6 +31,11 @@ static inline bool context_tracking_enabled(void)
> return static_branch_unlikely(_tracking_key);
> }
>
> +static inline bool context_tracking_enabled_cpu(int cpu)
> +{
> + return per_cpu(context_tracking.active, cpu);
> +}
> +
> static inline bool context_tracking_enabled_this_cpu(void)
> {
> return __this_cpu_read(context_tracking.active);
Should not the last two be something like:
static inline bool context_tracking_enabled_cpu(int cpu)
{
return context_tracking_enabled() && per_cpu(context_tracking.active,
cpu);
}
static inline bool context_tracking_enabled_this_cpu(void)
{
return context_tracking_enabled() &&
__this_cpu_read(context_tracking.active);
}
Because, afaict, not all callsites first check the static key.
Re: [PATCH 13/25] context_tracking: Introduce context_tracking_enabled_cpu()
On Wed, Nov 14, 2018 at 03:45:57AM +0100, Frederic Weisbecker wrote:
> This allows us to check if a remote CPU runs context tracking
> (ie: is nohz_full). We'll need that to reliably support "nice"
> accounting on kcpustat.
>
> Signed-off-by: Frederic Weisbecker
> Cc: Yauheni Kaliuta
> Cc: Thomas Gleixner
> Cc: Rik van Riel
> Cc: Peter Zijlstra
> Cc: Wanpeng Li
> Cc: Ingo Molnar
> ---
> include/linux/context_tracking_state.h | 6 ++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/context_tracking_state.h
> b/include/linux/context_tracking_state.h
> index 08f125f..5877177 100644
> --- a/include/linux/context_tracking_state.h
> +++ b/include/linux/context_tracking_state.h
> @@ -31,6 +31,11 @@ static inline bool context_tracking_enabled(void)
> return static_branch_unlikely(_tracking_key);
> }
>
> +static inline bool context_tracking_enabled_cpu(int cpu)
> +{
> + return per_cpu(context_tracking.active, cpu);
> +}
> +
> static inline bool context_tracking_enabled_this_cpu(void)
> {
> return __this_cpu_read(context_tracking.active);
Should not the last two be something like:
static inline bool context_tracking_enabled_cpu(int cpu)
{
return context_tracking_enabled() && per_cpu(context_tracking.active,
cpu);
}
static inline bool context_tracking_enabled_this_cpu(void)
{
return context_tracking_enabled() &&
__this_cpu_read(context_tracking.active);
}
Because, afaict, not all callsites first check the static key.
[PATCH 13/25] context_tracking: Introduce context_tracking_enabled_cpu()
This allows us to check if a remote CPU runs context tracking
(ie: is nohz_full). We'll need that to reliably support "nice"
accounting on kcpustat.
Signed-off-by: Frederic Weisbecker
Cc: Yauheni Kaliuta
Cc: Thomas Gleixner
Cc: Rik van Riel
Cc: Peter Zijlstra
Cc: Wanpeng Li
Cc: Ingo Molnar
---
include/linux/context_tracking_state.h | 6 ++
1 file changed, 6 insertions(+)
diff --git a/include/linux/context_tracking_state.h
b/include/linux/context_tracking_state.h
index 08f125f..5877177 100644
--- a/include/linux/context_tracking_state.h
+++ b/include/linux/context_tracking_state.h
@@ -31,6 +31,11 @@ static inline bool context_tracking_enabled(void)
return static_branch_unlikely(_tracking_key);
}
+static inline bool context_tracking_enabled_cpu(int cpu)
+{
+ return per_cpu(context_tracking.active, cpu);
+}
+
static inline bool context_tracking_enabled_this_cpu(void)
{
return __this_cpu_read(context_tracking.active);
@@ -43,6 +48,7 @@ static inline bool context_tracking_in_user(void)
#else
static inline bool context_tracking_in_user(void) { return false; }
static inline bool context_tracking_enabled(void) { return false; }
+static inline bool context_tracking_enabled_cpu(int cpu) { return false; }
static inline bool context_tracking_enabled_this_cpu(void) { return false; }
#endif /* CONFIG_CONTEXT_TRACKING */
--
2.7.4
[PATCH 13/25] context_tracking: Introduce context_tracking_enabled_cpu()
This allows us to check if a remote CPU runs context tracking
(ie: is nohz_full). We'll need that to reliably support "nice"
accounting on kcpustat.
Signed-off-by: Frederic Weisbecker
Cc: Yauheni Kaliuta
Cc: Thomas Gleixner
Cc: Rik van Riel
Cc: Peter Zijlstra
Cc: Wanpeng Li
Cc: Ingo Molnar
---
include/linux/context_tracking_state.h | 6 ++
1 file changed, 6 insertions(+)
diff --git a/include/linux/context_tracking_state.h
b/include/linux/context_tracking_state.h
index 08f125f..5877177 100644
--- a/include/linux/context_tracking_state.h
+++ b/include/linux/context_tracking_state.h
@@ -31,6 +31,11 @@ static inline bool context_tracking_enabled(void)
return static_branch_unlikely(_tracking_key);
}
+static inline bool context_tracking_enabled_cpu(int cpu)
+{
+ return per_cpu(context_tracking.active, cpu);
+}
+
static inline bool context_tracking_enabled_this_cpu(void)
{
return __this_cpu_read(context_tracking.active);
@@ -43,6 +48,7 @@ static inline bool context_tracking_in_user(void)
#else
static inline bool context_tracking_in_user(void) { return false; }
static inline bool context_tracking_enabled(void) { return false; }
+static inline bool context_tracking_enabled_cpu(int cpu) { return false; }
static inline bool context_tracking_enabled_this_cpu(void) { return false; }
#endif /* CONFIG_CONTEXT_TRACKING */
--
2.7.4
