Re: [PATCH] fs/proc: Move kfree outside pde_unload_lock

[Nathan Zimmer]

On Wed, Aug 22, 2012 at 11:42:58PM +0200, Eric Dumazet wrote:
> On Wed, 2012-08-22 at 20:28 +0200, Eric Dumazet wrote:
> 
> > 
> > Thats interesting, but if you really want this to fly, one RCU
> > conversion would be much better ;)
> > 
> > pde_users would be an atomic_t and you would avoid the spinlock
> > contention.
> 
> Here is what I had in mind, I would be interested to know how it helps a 512 core machine ;)
> 

Here are the results and they look great.

cpuinfo	baseline	moved kfree	Rcu 
tasks	read-sec	read-sec	read-sec
1	0.0141		0.0141		0.0141
2	0.0140		0.0140		0.0142
4	0.0140		0.0141		0.0141
8	0.0145		0.0145		0.0140
16	0.0553		0.0548		0.0168
32	0.1688		0.1622		0.0549
64	0.5017		0.3856		0.1690
128	1.7005		0.9710		0.5038
256	5.2513		2.6519		2.0804
512	8.0529		6.2976		3.0162



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/