Re: [PATCH v9 04/19] qspinlock: Extract out the exchange of tail code word

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Apr 17, 2014 at 11:03:56AM -0400, Waiman Long wrote:
> @@ -192,36 +220,25 @@ void queue_spin_lock_slowpath(struct qspinlock *lock, u32 val)
>  	node->next = NULL;
>  
>  	/*
> +	 * We touched a (possibly) cold cacheline; attempt the trylock once
> +	 * more in the hope someone let go while we weren't watching as long
> +	 * as no one was queuing.
>  	 */
> +	if (!(val & _Q_TAIL_MASK) && queue_spin_trylock(lock))
> +		goto release;

But you just did a potentially very expensive op; @val isn't
representative anymore!
--
To unsubscribe from this list: send the line "unsubscribe linux-arch" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Newbies]     [x86 Platform Driver]     [Netdev]     [Linux Wireless]     [Netfilter]     [Bugtraq]     [Linux Filesystems]     [Yosemite Discussion]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]

  Powered by Linux