On Mon, 31 Oct 2005, Paul E. McKenney wrote:
>
> The attached patch uses RCU to avoid the need to acquire tasklist_lock
> in the single-thread case of clock_gettime(). Still acquires tasklist_lock
> when asking for the time of a (potentially multithreaded) process.
>
> Experimental, has been touch-tested on x86 and POWER. Requires RCU on
> task_struct. Further more focused testing in progress.
>
> Thoughts? (Why? Some off-list users want to be able to monitor CPU
> consumption of specific threads. They need to do so quite frequently,
> so acquiring tasklist_lock is inappropriate.)
Not my area at all, but this looks really dodgy to me, Paul:
could you explain it further?
First off, I don't see what's "RCU" about it at all. Essentially,
you're replacing read_lock(&tasklist_lock) by preempt_disable(),
but calling it by the fancier rcu_read_lock() alias. I thought there
would need to be some more infrastructure to make this RCU and safe?
Hugh
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
