Re: [patch] lockless, scalable get_pid(), for_each_process() elimination, 2.5.35-BK

From: Rogier Wolff <R.E.Wolff@BitWizard.nl>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Rik van Riel <riel@conectiva.com.br>,
	Andries Brouwer <aebr@win.tue.nl>, Ingo Molnar <mingo@elte.hu>,
	William Lee Irwin III <wli@holomorphy.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [patch] lockless, scalable get_pid(), for_each_process() elimination, 2.5.35-BK
Date: Wed, 18 Sep 2002 23:46:37 +0200	[thread overview]
Message-ID: <20020918234637.A29270@bitwizard.nl> (raw)
In-Reply-To: <Pine.LNX.4.44.0209180938590.1913-100000@home.transmeta.com>

On Wed, Sep 18, 2002 at 09:48:24AM -0700, Linus Torvalds wrote:
> 
> > On Wed, 18 Sep 2002, Linus Torvalds wrote:
> > 
> > > I would suggest something like this:
> > >  - make pid_max start out at 32k or whatever, to make "ps" look nice if
> > >    nothing else.
> > >  - every time we have _any_ trouble at all with looking up a new pid, we
> > >    double pid_max.
> > 
> > > +		if (nr_threads > pid_max >> 4)

> The people who care about ps being pretty will probably never see more 
> than 5 digits.

Agreed. While on the topic of number of digits: If this is in place
we could easily start out pid_max at say 9999, fitting the pids in
one less digit than we normally do now. 

(I've always thought we should have sticked with pid_max at the
traditional Unix value of 32000, and not 32767).

			Roger. 

-- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
* The Worlds Ecosystem is a stable system. Stable systems may experience *
* excursions from the stable situation. We are currenly in such an       * 
* excursion: The stable situation does not include humans. ***************