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

From: Mitchell Erblich
Date: Fri Jul 10 2009 - 21:48:53 EST


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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