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From: ebiederm@xmission.com (Eric W. Biederman)
To: Robin Holt <holt@sgi.com>
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Date: Thu, 31 Jul 2008 15:04:56 -0700
In-Reply-To: <20080731200835.GK9663@sgi.com> (Robin Holt's message of "Thu, 31
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Subject: Re: [Patch] Scale pidhash_shift/pidhash_size up based on num_possible_cpus().
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Robin Holt <holt@sgi.com> writes:

> Like so???
>
> I have not tested this yet.

Looks reasonable to me.

In what circumstances was the lookup in the pid hash table with
long changes causing a performance slowdown?.  We don't perform
a lot of lookups.


> -	pidhash_shift = min(12, pidhash_shift);
> +	pidhash_shift = min(fls(PID_MAX_LIMIT) - 6, pidhash_shift);
>  	pidhash_size = 1 << pidhash_shift;