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From: "dan carpenter" <error27@email.com>
To: linux-kernel@vger.kernel.org
Cc: rusty@rustcorp.com.au, torvalds@transmeta.com, davem@redhat.com
Subject: calling schedule() from interupt context
Date: Fri, 22 Nov 2002 03:54:41 -0500	[thread overview]
Message-ID: <20021122085441.2127.qmail@email.com> (raw)

I was running a script to find which functions call schedule() and I across something 
strange.  

In drivers/net/tokenring/3c359.c xl_interrupt() calls schedule().
The path from xl_interupt to schedule is:
xl_rx ==> netif_rx ==> 
kfree_skb ==> __kfree_skb ==> 
secpath_put ==> __secpath_destroy ==> 
xfrm_state_put ==> __xfrm_state_destroy ==> xfrm_put_type ==> 
module_put ==> put_cpu ==> preempt_schedule ==> schedule

The problem is that xl_interrupt is the interrupt handler for the 3c359 driver and
I did not think it was legal to call shedule() from interrupt context.

The second thing is that module_put() has a line that looks like it's decrementing
the module reference count (Is it supposed to do that?):
176                  local_dec(&module->ref[cpu].count);

The third thing I was wondering is:  xl_interupt is holding a 
spin_lock(&xl_priv->xl_lock).   I know that you're not supposed to call shedule()
while holding a spin lock, but is it ok to call preempt_schedule()?

thanks,
dan carpenter

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             reply	other threads:[~2002-11-22  9:00 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-11-22  8:54 dan carpenter [this message]
2002-11-22  9:09 ` calling schedule() from interupt context David S. Miller
2002-11-22  9:16   ` Robert Love
2002-11-24 21:42   ` Rusty Russell
2002-11-24 22:41     ` Robert Love
2002-11-22  9:14 ` Robert Love
  -- strict thread matches above, loose matches on Subject: below --
2002-11-22 16:04 dan carpenter
2002-11-22 16:11 ` Robert Love

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