On Mon, 26 Dec 2005, Arjan van de Ven wrote:
>
> > hm. 16 CPUs hitting the same semaphore at great arrival rates. The cost
> > of a short spin is much less than the cost of a sleep/wakeup. The machine
> > was doing 100,000 - 200,000 context switches per second.
>
> interesting.. this might be a good indication that a "spin a bit first"
> mutex slowpath for some locks might be worth implementing...
No, please don't.
Almost always it's a huge sign that the locking is totally broken.
And yes, the fix was to _fix_ the ext3 locking. Not to make semaphores
spin. The ext3 locking was using a semaphore for totally the wrong
reasons, it made zero sense at all.
I think it's fixed now.
Linus
-
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]
