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From: Ingo Molnar <mingo@elte.hu>
To: Andrew Morton <akpm@osdl.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
	linux-kernel@vger.kernel.org, greg@kroah.com, zaitcev@redhat.com
Subject: Re: 2.6.15-mm4: sem2mutex problem in USB OHCI
Date: Mon, 16 Jan 2006 09:21:59 +0100	[thread overview]
Message-ID: <20060116082159.GA9744@elte.hu> (raw)
In-Reply-To: <20060114160526.228da734.akpm@osdl.org>


* Andrew Morton <akpm@osdl.org> wrote:

> >  Badness in __mutex_trylock_slowpath at kernel/mutex.c:281
> > 
> >  Call Trace: <IRQ> <ffffffff80148d8d>{mutex_trylock+141}
> >
> >         <ffffffff880abaf0>{:ohci_hcd:ohci_hub_status_data+480}
> >         <ffffffff802d25d0>{rh_timer_func+0} <ffffffff802d24c3>{usb_hcd_poll_rh_status+67}
> >         <ffffffff802d25d0>{rh_timer_func+0} <ffffffff802d25d9>{rh_timer_func+9}
> >         <ffffffff8013a3cc>{run_timer_softirq+396}

> err, taking a mutex from softirq context.

btw., i'm wondering how the down_trylock() can be correct code: what 
guarantees progress if the trylock happens to fail all the time? (or 
just happens to fail frequently, due to some other, unrelated dev->mutex 
workload)

Shouldnt this code use some other solution to process these timed events 
more robustly?

	Ingo

      parent reply	other threads:[~2006-01-16  8:21 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-01-14 23:58 2.6.15-mm4: sem2mutex problem in USB OHCI Rafael J. Wysocki
2006-01-15  0:05 ` Andrew Morton
2006-01-15  4:38   ` Ingo Molnar
2006-01-15 15:31     ` Rafael J. Wysocki
2006-01-16 22:51     ` Greg KH
2006-01-16  8:21   ` Ingo Molnar [this message]

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