Thunder from the hill wrote:
> On Sun, 7 Jul 2002, Dave Hansen wrote:
>
>>Old Blue? 23 isn't _that_ old!
>
> Obviously, you never read that book about the IBM s/370 named
> "Old Blue"...
Nope. I missed that one. Something like "The Little Mainfraime that
could?"
>>BKL use isn't right or wrong -- it isn't a case of creating a deadlock
>>or a race. I'm picking a relatively random function from "grep -r
>>lock_kernel * | grep /usb/". I'll show what I think isn't optimal
>>about it.
>>
>>"up" is a local variable. There is no point in protecting its
>>allocation. If the goal is to protect data inside "up", there should
>>probably be a subsystem-level lock for all "struct uhci_hcd"s or a
>>lock contained inside of the structure itself. Is this the kind of
>>example you're looking for?
>
> So the BKL isn't wrong here, but incorrectly used?
Not even incorrect, but badly used. But, this was probably another
VFS push.
> Is it really okay to "lock the whole kernel" because of one struct file?
> This brings us back to spinlocks...
Don't think of it as locking the kernel, that isn't really what it
does anymore. You really need to think of it as a special spinlock.
> You're possibly right about this one. What did Greg K-H say?
Only time will tell...
-- Dave Hansen haveblue@us.ibm.com- 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/
This archive was generated by hypermail 2b29 : Sun Jul 07 2002 - 22:00:18 EST