Re: [PATCH] lock assertion macros for 2.5.30

[Paul Menage]

In article <[e-mail]>,
 you write:
>
>> Agreed.  I'll post another patch that doesn't mess with the scsi
>> stuff.  Maybe later I can put together a useful
>> 'lock-not-held-on-this-cpu' macro.
>
>You don't need to put this in a macro.  This test is valid
>for ALL spinlocks in the kernel and can be done from inside
>the spin_lock() macro itself, when spinlock debugging is on.
>

There are some cases where this might not be true - e.g. in the
migration code in at least one version of the O(1) scheduler (included
in RedHat's 2.4.18-4) the migration_lock is taken on one CPU and
released on another (following an IPI being sent from the CPU that took
the lock).

So at the very least you'd need a separate set of spinlock primitives
that don't perform this test, which would have to be used by anyone
taking/releasing such a lock.

Paul