> -----Original Message----- > From: kernelnewbies-bounces+jharan=bytemobile.com@xxxxxxxxxxxxxxxxx > [mailto:kernelnewbies- > bounces+jharan=bytemobile.com@xxxxxxxxxxxxxxxxx] On Behalf Of Dave > Hylands > Sent: Thursday, November 10, 2011 11:07 AM > To: Kai Meyer > Cc: kernelnewbies@xxxxxxxxxxxxxxxxx > Subject: Re: Spinlocks and interrupts > > Hi Kai, > > On Thu, Nov 10, 2011 at 10:14 AM, Kai Meyer <kai@xxxxxxxxxx> wrote: > > I think I get it. I'm hitting the scheduling while atomic because I'm > > calling my function from a struct bio's endio function, which is > > probably running with a lock held somewhere else, and then my mutex > > sleeps, while the spin_lock functions do not sleep. > > Actually, just holding a lock doesn't create an atomic context. I believe on kernels with kernel pre-emption enabled the act of taking the lock disables pre-emption. If it didn't work this way you could end up taking the lock in one process context and while the lock was held get pre-empted. Then another process tries to take the lock and you dead lock. Jeff Haran _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
