From: Linus Torvalds <torvalds@transmeta.com>
To: Andries Brouwer <aebr@win.tue.nl>
Cc: Ingo Molnar <mingo@elte.hu>,
William Lee Irwin III <wli@holomorphy.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: quadratic behaviour
Date: Sat, 21 Sep 2002 10:06:02 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.44.0209210958080.2702-100000@home.transmeta.com> (raw)
In-Reply-To: <20020921125626.GA15603@win.tue.nl>
On Sat, 21 Sep 2002, Andries Brouwer wrote:
> >
> > So, why do you think this problem has been fixed?
>
> Let me repeat this, and call it an observation instead of a question,
> so that you do not think I am in doubt.
The reason Ingo thinks it is fixed is that it is fixed for the case of
having millions of threads - because the threads (with the new thread
library) won't show up on the "for_each_process()" loop. Which makes
threaded apps look a lot better on ps and top (we'll have to expose them
some day under /proc/<pid>/thread/<tid>/, but that's another matter)
But the quadratic behaviour wrt processes clearly isn't fixed. Suggestions
welcome (and we'll need to avoid the same quadratic behaviour wrt the
threads when we expose them).
The only "obvious" thing to do is to insert markers into the process list,
and have "for_each_process()" automatically skip the marker entries. There
probably wouldn't be all that many things that would ever notice if that
were done (excatly because most things that want to traverse the list use
"for_each_process()" already). And then instead of using "index", you
carry the marker thing around...
Linus
next prev parent reply other threads:[~2002-09-21 17:00 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-17 23:06 [patch] lockless, scalable get_pid(), for_each_process() elimination, 2.5.35-BK Ingo Molnar
2002-09-18 0:22 ` William Lee Irwin III
2002-09-18 1:27 ` David S. Miller
2002-09-18 2:22 ` William Lee Irwin III
2002-09-18 10:11 ` Ingo Molnar
2002-09-18 14:28 ` William Lee Irwin III
2002-09-18 12:32 ` Andries Brouwer
2002-09-18 12:56 ` Ingo Molnar
2002-09-18 16:17 ` Linus Torvalds
2002-09-18 16:46 ` Ingo Molnar
2002-09-18 16:57 ` Ingo Molnar
2002-09-18 18:28 ` Andries Brouwer
2002-09-18 18:27 ` William Lee Irwin III
2002-09-18 19:00 ` Ingo Molnar
2002-09-18 20:11 ` Andries Brouwer
2002-09-18 20:29 ` William Lee Irwin III
2002-09-18 21:15 ` Andries Brouwer
2002-09-19 3:05 ` Ingo Molnar
2002-09-19 13:11 ` Andries Brouwer
2002-09-21 12:56 ` quadratic behaviour Andries Brouwer
2002-09-21 17:06 ` Linus Torvalds [this message]
2002-09-21 17:35 ` William Lee Irwin III
2002-09-21 17:49 ` Ingo Molnar
2002-09-21 17:46 ` William Lee Irwin III
2002-09-18 14:49 ` [patch] lockless, scalable get_pid(), for_each_process() elimination, 2.5.35-BK William Lee Irwin III
2002-09-18 15:01 ` Cort Dougan
2002-09-18 15:33 ` Ingo Molnar
2002-09-18 15:31 ` yodaiken
2002-09-18 15:35 ` Cort Dougan
2002-09-18 15:37 ` Rik van Riel
2002-09-18 15:50 ` Alan Cox
2002-09-18 18:31 ` Andries Brouwer
2002-09-18 18:32 ` William Lee Irwin III
2002-09-18 16:15 ` Linus Torvalds
2002-09-18 16:32 ` Rik van Riel
2002-09-18 16:48 ` Linus Torvalds
2002-09-18 17:31 ` Ingo Molnar
2002-09-18 21:46 ` Rogier Wolff
2002-09-18 16:41 ` Ingo Molnar
2002-09-18 16:45 ` William Lee Irwin III
2002-09-18 16:59 ` Linus Torvalds
2002-09-18 17:36 ` Ingo Molnar
2002-09-18 17:36 ` William Lee Irwin III
2002-09-18 17:46 ` Linus Torvalds
2002-09-18 17:47 ` William Lee Irwin III
2002-09-18 17:59 ` Ingo Molnar
2002-09-18 17:50 ` William Lee Irwin III
2002-09-18 18:07 ` Ingo Molnar
2002-09-19 19:27 ` Martin Mares
2002-09-17 15:31 ` Pavel Machek
2002-09-19 20:07 ` Richard B. Johnson
2002-09-18 16:46 ` Rik van Riel
2002-09-18 16:53 ` Linus Torvalds
2002-09-18 17:00 ` Rik van Riel
2002-09-18 17:16 ` Linus Torvalds
2002-09-18 17:28 ` Ingo Molnar
2002-09-18 17:38 ` Ingo Molnar
2002-09-18 17:24 ` Ingo Molnar
2002-09-18 17:30 ` Linus Torvalds
2002-09-18 17:35 ` Cort Dougan
2002-09-18 17:43 ` Rik van Riel
2002-09-18 17:48 ` Martin J. Bligh
2002-09-18 17:57 ` Cort Dougan
2002-09-18 18:08 ` Martin J. Bligh
2002-09-18 18:28 ` Ingo Molnar
2002-09-18 18:33 ` Linus Torvalds
2002-09-18 18:51 ` Ingo Molnar
2002-09-18 18:56 ` interruptible_sleep_on_timeout() and signals Imran Badr
2002-09-19 7:16 ` David Woodhouse
2002-09-18 19:53 ` [patch] lockless, scalable get_pid(), for_each_process() elimination, 2.5.35-BK Martin J. Bligh
2002-09-22 0:34 ` Andrea Arcangeli
2002-09-22 10:02 ` Ingo Molnar
2002-09-22 15:27 ` Andrea Arcangeli
2002-09-18 18:02 ` Ingo Molnar
2002-09-18 17:58 ` Cort Dougan
2002-09-18 18:14 ` Ingo Molnar
2002-09-18 17:54 ` Alan Cox
2002-09-18 17:54 ` Ingo Molnar
2002-09-18 18:00 ` yodaiken
2002-09-18 18:21 ` Ingo Molnar
2002-09-18 18:33 ` yodaiken
2002-09-18 16:55 ` Alan Cox
2002-09-21 14:15 quadratic behaviour Manfred Spraul
2002-09-21 17:02 ` William Lee Irwin III
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