what causes SpinLockSpinningForTooLong?

NTDEV
1

Good Day,

I was wondering what causes the nt!SpinLockSpinningForTooLong breakpoint to
happen?

Best Regards,
Rikki Tamayo

2

Rikki wrote:

I was wondering what causes the nt!SpinLockSpinningForTooLong breakpoint to
happen?

Good for you for using the checked build!

Nicely reported problem, isn’t it? Somebody should really add a
DbgPrint(…) in the kernel for this someday. Sigh! So much to do…

Anyhow, this happens on the x86 checked build, when you spin waiting for
a spin lock to become free for “an unreasonably long period of time” (55
clock ticks).

This usually means you’ve acquired the lock someplace (in thread context
X) and failed to release it, and now you’re trying to acquire it (in
thread context Y).

As an interesting aside, if you attempt to recursively acquire a spin
lock in the same thread context (on the x86 checked build) you get a
BSOD with SPIN_LOCK_ALREADY_OWNED.

Peter
OSR

3

At the risk of stating the obvious: you are waiting for a spinlock and too
much time has elapsed. This only happens in the checked build of the OS and
the assumption is that you have a debugger attached and that you would like
to understand why you are waiting. I believe the timeout is on the order of
50 or so ticks - at 15ms a tick this is 0.75 seconds. Note that if you
continue from the breakpoint (it is not a bugcheck, just a breakpoint) you
will get another 50 or so ticks.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Rikki
Sent: Wednesday, July 07, 2004 6:30 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] what causes SpinLockSpinningForTooLong?

Good Day,

I was wondering what causes the nt!SpinLockSpinningForTooLong
breakpoint to happen?

Best Regards,
Rikki Tamayo

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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4

Deadlock on a spinlock.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Rikki”
To: “Windows System Software Devs Interest List”
Sent: Thursday, July 08, 2004 2:29 AM
Subject: [ntdev] what causes SpinLockSpinningForTooLong?

> Good Day,
>
> I was wondering what causes the nt!SpinLockSpinningForTooLong breakpoint to
> happen?
>
> Best Regards,
> Rikki Tamayo
>
>
>
>
> —
> Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
>
> You are currently subscribed to ntdev as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com