2022-12-06 17:41:52

by Marcelo Tosatti

Subject: [PATCH v9 1/5] mm/vmstat: Add CPU-specific variable to track a vmstat discrepancy

From: Aaron Tomlin <[email protected]>

Introduce a CPU-specific variable namely vmstat_dirty to indicate
if a vmstat imbalance is present for a given CPU. Therefore, at
the appropriate time, we can fold all the remaining differentials.
This patch also provides trivial helpers for modification and testing.

Signed-off-by: Aaron Tomlin <[email protected]>
---
mm/vmstat.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

Index: linux-2.6/mm/vmstat.c
===================================================================
--- linux-2.6.orig/mm/vmstat.c
+++ linux-2.6/mm/vmstat.c
@@ -194,6 +194,22 @@ void fold_vm_numa_events(void)
#endif

#ifdef CONFIG_SMP
+static DEFINE_PER_CPU_ALIGNED(bool, vmstat_dirty);
+
+static inline void vmstat_mark_dirty(void)
+{
+ this_cpu_write(vmstat_dirty, true);
+}
+
+static inline void vmstat_clear_dirty(void)
+{
+ this_cpu_write(vmstat_dirty, false);
+}
+
+static inline bool is_vmstat_dirty(void)
+{
+ return this_cpu_read(vmstat_dirty);
+}

int calculate_pressure_threshold(struct zone *zone)
{

2022-12-14 13:34:05

by Frederic Weisbecker

Subject: Re: [PATCH v9 1/5] mm/vmstat: Add CPU-specific variable to track a vmstat discrepancy

On Tue, Dec 06, 2022 at 01:18:27PM -0300, Marcelo Tosatti wrote:
> From: Aaron Tomlin <[email protected]>
>
> Introduce a CPU-specific variable namely vmstat_dirty to indicate
> if a vmstat imbalance is present for a given CPU. Therefore, at
> the appropriate time, we can fold all the remaining differentials.
> This patch also provides trivial helpers for modification and testing.
>
> Signed-off-by: Aaron Tomlin <[email protected]>

Your SOB is also missing here and on other patches.

Thanks.

> ---
> mm/vmstat.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> Index: linux-2.6/mm/vmstat.c
> ===================================================================
> --- linux-2.6.orig/mm/vmstat.c
> +++ linux-2.6/mm/vmstat.c
> @@ -194,6 +194,22 @@ void fold_vm_numa_events(void)
> #endif
>
> #ifdef CONFIG_SMP
> +static DEFINE_PER_CPU_ALIGNED(bool, vmstat_dirty);
> +
> +static inline void vmstat_mark_dirty(void)
> +{
> + this_cpu_write(vmstat_dirty, true);
> +}
> +
> +static inline void vmstat_clear_dirty(void)
> +{
> + this_cpu_write(vmstat_dirty, false);
> +}
> +
> +static inline bool is_vmstat_dirty(void)
> +{
> + return this_cpu_read(vmstat_dirty);
> +}
>
> int calculate_pressure_threshold(struct zone *zone)
> {
>
>