Re: cpusets: only wakeup kswapd for zones in the current cpuset

[Paul Jackson <pj@sgi.com>]

Three months ago, Christoph wrote:
> If we get under some memory pressure in a cpuset (we only scan zones
> that are in the cpuset for memory) then kswapd is woken
> up for all zones. This patch only wakes up kswapd in zones that are
> part of the current cpuset.
> 
> Signed-off-by: Christoph Lameter <clameter@sgi.com>
> 
> Index: linux-2.6.16-rc2/mm/page_alloc.c
> ===================================================================
> --- linux-2.6.16-rc2.orig/mm/page_alloc.c	2006-02-02 22:03:08.000000000 -0800
> +++ linux-2.6.16-rc2/mm/page_alloc.c	2006-02-08 00:05:09.000000000 -0800
> @@ -923,7 +923,8 @@ restart:
>  		goto got_pg;
>  
>  	do {
> -		wakeup_kswapd(*z, order);
> +		if (cpuset_zone_allowed(*z, gfp_mask))
> +			wakeup_kswapd(*z, order);
>  	} while (*(++z));
>  
>  	/*
> 

Christoph,

Does this patch serve any use?  Chris Wright just noticed (in private
email) that wakeup_kswapd() already contains a check for cpuset
confinement, so it would seem the above added check is superfluous.

Thanks.

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.925.600.0401