Re: [RFC 07/15] slub: Add defrag_used_ratio field and sysfs support

From: Tycho Andersen <tycho@tycho.ws>
To: "Tobin C. Harding" <tobin@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Christopher Lameter <cl@linux.com>,
	Pekka Enberg <penberg@cs.helsinki.fi>,
	Matthew Wilcox <willy@infradead.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC 07/15] slub: Add defrag_used_ratio field and sysfs support
Date: Fri, 8 Mar 2019 09:01:51 -0700	[thread overview]
Message-ID: <20190308160151.GC373@cisco> (raw)
In-Reply-To: <20190308041426.16654-8-tobin@kernel.org>

On Fri, Mar 08, 2019 at 03:14:18PM +1100, Tobin C. Harding wrote:
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -3642,6 +3642,7 @@ static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
>  
>  	set_cpu_partial(s);
>  
> +	s->defrag_used_ratio = 30;
>  #ifdef CONFIG_NUMA
>  	s->remote_node_defrag_ratio = 1000;
>  #endif
> @@ -5261,6 +5262,28 @@ static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
>  }
>  SLAB_ATTR_RO(destroy_by_rcu);
>  
> +static ssize_t defrag_used_ratio_show(struct kmem_cache *s, char *buf)
> +{
> +	return sprintf(buf, "%d\n", s->defrag_used_ratio);
> +}
> +
> +static ssize_t defrag_used_ratio_store(struct kmem_cache *s,
> +				       const char *buf, size_t length)
> +{
> +	unsigned long ratio;
> +	int err;
> +
> +	err = kstrtoul(buf, 10, &ratio);
> +	if (err)
> +		return err;
> +
> +	if (ratio <= 100)
> +		s->defrag_used_ratio = ratio;
    else
        return -EINVAL;

maybe?

Tycho