From: Ingo Molnar <mingo@elte.hu>
To: kus Kusche Klaus <kus@keba.com>
Cc: stern@rowland.harvard.edu, linux-usb-users@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: 2.6.11, USB: High latency?
Date: Fri, 1 Apr 2005 15:41:27 +0200 [thread overview]
Message-ID: <20050401134127.GA4992@elte.hu> (raw)
In-Reply-To: <AAD6DA242BC63C488511C611BD51F3673231DB@MAILIT.keba.co.at>
* kus Kusche Klaus <kus@keba.com> wrote:
> IRQ 7-724 0d..1 1us : end_8259A_irq (do_hardirq)
> IRQ 7-724 0d..1 1us!: enable_8259A_irq (do_hardirq)
> IRQ 7-724 0d... 832us : do_hardirq (do_irqd)
> IRQ 7-724 0d... 833us : trace_irqs_on (do_hardirq)
> mmap-1000 0d.h1 21us : end_8259A_irq (__do_IRQ)
> mmap-1000 0d.h1 22us!: enable_8259A_irq (__do_IRQ)
> mmap-1000 0d.h. 662us : irq_exit (do_IRQ)
> mmap-1000 0d..1 662us : do_softirq (irq_exit)
> mmap-1000 0d.h. 0us : do_IRQ (c012d6d5 7 0)
> mmap-1000 0d.h1 2us!: mask_and_ack_8259A (__do_IRQ)
> mmap-1000 0d.h1 938us : redirect_hardirq (__do_IRQ)
> mmap-1000 0d.h1 939us : wake_up_process (redirect_hardirq)
such 'freezes' almost certainly signal some sort of hardware latency -
some device holding the system bus up during DMA. There is no
algorithmic reason for any of those steps above to take several hundreds
of microseconds.
Ingo
next prev parent reply other threads:[~2005-04-01 13:41 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-04-01 13:16 2.6.11, USB: High latency? kus Kusche Klaus
2005-04-01 13:41 ` Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-04-04 8:03 kus Kusche Klaus
2005-04-04 8:36 ` Ingo Molnar
2005-04-04 19:40 ` Alan Stern
2005-04-01 6:46 kus Kusche Klaus
2005-04-01 17:20 ` Alan Stern
2005-03-31 12:12 kus Kusche Klaus
2005-03-31 11:15 kus Kusche Klaus
2005-03-31 16:48 ` Alan Stern
2005-03-30 22:57 David Brownell
2005-03-31 0:43 ` Lee Revell
2005-03-31 1:13 ` David Brownell
2005-03-31 1:21 ` Lee Revell
2005-03-31 1:32 ` David Brownell
2005-03-31 0:51 ` Lee Revell
2005-03-31 1:28 ` David Brownell
2005-03-31 1:32 ` Lee Revell
2005-03-31 1:40 ` David Brownell
2005-03-31 1:44 ` Lee Revell
2005-03-31 1:39 ` Lee Revell
2005-03-30 13:51 kus Kusche Klaus
2005-03-30 15:55 ` Alan Stern
2005-03-30 21:28 ` Lee Revell
2005-03-31 11:30 ` Ingo Molnar
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