Messages in this thread | | | Date | Thu, 22 Jun 2006 18:40:25 -0700 | From | Andrew Morton <> | Subject | Re: [patch] lock validator: rtmutex unlock order annotation |
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On Thu, 22 Jun 2006 10:57:06 +0200 Ingo Molnar <mingo@elte.hu> wrote:
> rtmutex.c does a tricky piece of 'lock chain' logic spiced with trylock, > which has one particular codepath where we intentionally release the > locks in a different order as acquired. Annotate this for the lock > validator to not complain if CONFIG_DEBUG_NON_NESTED_UNLOCKS=y. > > Signed-off-by: Ingo Molnar <mingo@elte.hu> > --- > kernel/rtmutex.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > Index: linux/kernel/rtmutex.c > =================================================================== > --- linux.orig/kernel/rtmutex.c > +++ linux/kernel/rtmutex.c > @@ -243,7 +243,8 @@ static int rt_mutex_adjust_prio_chain(ta > plist_add(&waiter->list_entry, &lock->wait_list); > > /* Release the task */ > - spin_unlock_irqrestore(&task->pi_lock, flags); > + spin_unlock_non_nested(&task->pi_lock); > + local_irq_restore(flags);
y'know, if an innocent civilian were to stumble across this code he or she would wonder "wtf is that doing"?
He or she would then go to the definition of spin_unlock_non_nested() and would find it to be 100% comment-free.
IOW, hasty hackery is flying in all directions and the kernel is getting crappier as a result.
And that's OK for now, because at some stage I'll be dropping the whole lot so you can redo the series. But I just don't know what's in there any more and we'll need to re-changelog, re-document, re-comment and re-review everything in the for-real patch series. (ISTR having some minor comments and questions against the initial patch series?)
We'll need to review it for comprehensibility (hence maintainability).
We'll need to measure the configged-off code size increase.
I think we have quite a long way to go yet on this stuff. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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