Re: [BUG?] possible recursive locking detected

From: Ingo Molnar
Date: Thu Jul 27 2006 - 10:49:58 EST

* Anton Altaparmakov <aia21@xxxxxxxxx> wrote:

> Note that even the above patch is not a 100% solution. What
> guarantees are there that the page faulted in will still be around
> when it is read a few lines down the line in the code? Given
> sufficient parallel memory pressure/io pressure it can still cause the
> page to be evicted again immediately after it is faulted in...
> All the above patch does is to _dramatically_ reduce the race window
> for this happening but it does not eliminate it in theory (AFAICS).
> So if your stance is that deadlocks are completely unacceptable it
> still is not fixed. If your stance is that _really_ unlikely
> deadlocks are acceptable then it is fixed.

my 'stance' is pretty common-sense: exploitable deadlocks (it's possible
to force eviction of a page), or even hard-to-trigger but possible
deadlocks (which are not associated with hopeless resource exhaustation)
must be fixed.

couldnt we exclude the case of 'write writing to the same page it is
reading from' abuse, to avoid the deadlock problem?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at