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

From: Frederic Weisbecker <frederic@kernel.org>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: atomlin@redhat.com, cl@linux.com, tglx@linutronix.de,
	mingo@kernel.org, peterz@infradead.org, pauld@redhat.com,
	neelx@redhat.com, oleksandr@natalenko.name,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v9 1/5] mm/vmstat: Add CPU-specific variable to track a vmstat discrepancy
Date: Wed, 14 Dec 2022 14:06:22 +0100	[thread overview]
Message-ID: <20221214130622.GD1930067@lothringen> (raw)
In-Reply-To: <20221206162416.404740300@redhat.com>

On Tue, Dec 06, 2022 at 01:18:27PM -0300, Marcelo Tosatti wrote:
> From: Aaron Tomlin <atomlin@redhat.com>
> 
> 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 <atomlin@redhat.com>

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)
>  {
> 
> 