Re: [PATCH 2/2] Add /proc controls for pdflush threads

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 30 Dec 2008 16:12:33 -0700 Peter W Morreale <pmorreale@novell.com> wrote:

> From: \"Peter W. Morreale\" <pmorreale@novell.com>
> 
> This patch adds /proc entries to give the admin the ability to
> control the minimum and maximum number of pdflush threads.  This allows
> finer control of pdflush on both large and small machines.
> 
> The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and
> '/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions.

Why is this needed?  Where's the benefit?  What observations led you to
develop this patch?  etc.

> --- a/include/linux/sysctl.h
> +++ b/include/linux/sysctl.h
> @@ -205,6 +205,8 @@ enum
>  	VM_PANIC_ON_OOM=33,	/* panic at out-of-memory */
>  	VM_VDSO_ENABLED=34,	/* map VDSO into new processes? */
>  	VM_MIN_SLAB=35,		 /* Percent pages ignored by zone reclaim */
> +	VM_NR_PDFLUSH_THREADS_MAX=36, /* nr_pdflush_threads_max */
> +	VM_NR_PDFLUSH_THREADS_MIN=37, /* nr_pdflush_threads_min */
>  };

We don't do this any more...

>  		.proc_handler	= &proc_dointvec,
>  	},
>  	{
> +		.ctl_name	= VM_NR_PDFLUSH_THREADS_MIN,

please just use CTL_UNNUMBERED here.