linux-kernel - Re: Suggested code change : Simple : Scale pdflush threads from desktop to server

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Date:	Fri, 10 Jul 2009 18:48:39 -0700
From:	Mitchell Erblich <erblichs@...thlink.net>
To:	Mitchell Erblich <erblichs@...thlink.net>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Suggested code change : Simple : Scale pdflush threads from desktop to server

Sorry,

	IF Not rate limit. Missing not / !.
	if (!(printk_ratelimit() )) {


	Mitchell Erblich	
	================
	
On Jul 10, 2009, at 6:25 PM, Mitchell Erblich wrote:

> Group,
>
> 		pdflush threads clean dirty pages
>
> 	  Under the past simple assumption that a greater number of
> 	  page daemon threads will have the TENDENCY to clean
> 	  the pages faster.
>
> 	Another assumption is that a server will have at least 2x / 4x the
> 	number of drives and memory, so allocating more pdflush() threads
> 	makes sense.
>
> 	Relying on a recent change, code base on whether the system is
> 	a desktop or a server, scale the number of pdthreads() which would
> 	result in the below code change.
>
> 	The suggestion is to double the MIN number of threads and set the
> 	MAX number to 4x.
>
> 	./mm/pdflush.c
> 	/* Scale for a server */
> 	#define MIN_PDFLUSH_THREADS 	4		/* 2x desktop value */
> 	#define MAX_PDFLUSH_THREADS 	32		/* 4x desktop value */
>
>
> 	/*
> 	 * secondary suggestion is to add a DEBUG type /var/log/system  
> messages that
> 	 * will rate limit independent of desktop or server.
>         */
>
> 	else if (nr_pdflush_threads == MAX_PDFLUSH_THREADS) {
> 		   /* optional PDFLUSH msg */
> 		   if (printk_ratelimit() {
> 	 		                            printk(KERN_INFO  
> "MAX_PDFLUSH_THREADS Limited\n");
>                   }
>         }
> 	
>
> 	

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