RE: [PATCH] lib/spinlock_debug: avoid one thread can not obtain the spinlock for a long time.

[Wang, Xiaoming]

Dear Peter
	If we wait the end of loop as loops_per_jiffy. 
It may last more than 130s and local IRQ disabled at interval 
which may cause Hard LOCKUP. We break out in 1 second and
dump the stack for debug.

> -----Original Message-----
> From: Peter Zijlstra [mailto:peterz@xxxxxxxxxxxxx]
> Sent: Wednesday, April 30, 2014 2:06 PM
> To: Wang, Xiaoming
> Cc: mingo@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Liu, Chuansheng
> Subject: Re: [PATCH] lib/spinlock_debug: avoid one thread can not obtain
> the spinlock for a long time.
> 
> On Wed, Apr 30, 2014 at 01:04:31PM -0400, Wang, Xiaoming wrote:
> > loops_per_jiffy is larger than expectation that possible causes one
> > thread can not obtain the spin lock for a long time.
> > So use cpu_clock() to reach timeout in one second which can avoid
> HARD
> > LOCKUP.
> 
> This is just not making sense.. one thing is broken so then you tape on
> another? Fix the first already.
> 
> Also, why do you care?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/