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From: Andrew Morton <andrewm@uow.edu.au>
To: David Woodhouse <dwmw2@infradead.org>
Cc: Johannes Erdfelt <johannes@erdfelt.com>,
	Oleg Drokin <green@ixcelerator.com>,
	linux-kernel@vger.kernel.org
Subject: Re: hardcoded HZ in hub.c
Date: Wed, 22 Nov 2000 22:22:01 +1100	[thread overview]
Message-ID: <3A1BAC59.B0F124AF@uow.edu.au> (raw)
In-Reply-To: <20001121142616.L7764@sventech.com>, <20001121142616.L7764@sventech.com>  <20001121095626.F3431@valinux.com> <Pine.LNX.4.30.0011211912490.22252-100000@imladris.demon.co.uk> <4627.974890115@redhat.com>

David Woodhouse wrote:
> 
> johannes@erdfelt.com said:
> >  Multiple seconds in the worst case.
> 
> Well, I think the PCMCIA socket drivers would be happy with that. Depends
> what akpm also added to the list of tasks,

Nothing which sleeps for very long - mainly serial drivers which queue
a call to tty_hangup(), which immediately queues _another_ tq_scheduler
call to do_tty_hangup (Why?  Heaven knows).

> and whether Linus actually puts
> that patch into test12.

tq_scheduler is a bug.  You can't sleep, you can't call copy_*_user,
you can't call kmalloc non-atomically.  But we do do these things.
Really the only reason for using tq_scheduler is so you can acquire
the tasklist_lock or the files_lock. schedule_task() is fine for that.

tq_scheduler must die.
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  reply	other threads:[~2000-11-22 11:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-11-17  9:54 hardcoded HZ in hub.c Oleg Drokin
2000-11-20 20:17 ` Johannes Erdfelt
2000-11-21 10:13 ` David Woodhouse
2000-11-21 17:56   ` Johannes Erdfelt
2000-11-21 19:13     ` David Woodhouse
2000-11-21 19:26       ` Johannes Erdfelt
2000-11-22 10:48       ` David Woodhouse
2000-11-22 11:22         ` Andrew Morton [this message]
2000-11-22 11:26         ` David Woodhouse
2000-11-22 11:34           ` Andrew Morton
2000-11-22 11:47           ` David Woodhouse

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