Thread (86 messages) 86 messages, 13 authors, 2011-06-18

Re: REGRESSION: Performance regressions from switching anon_vma->lock to mutex

From: Tim Chen <hidden>
Date: 2011-06-15 18:42:46
Also in: lkml

On Wed, 2011-06-15 at 18:45 +0200, Peter Zijlstra wrote:
On Wed, 2011-06-15 at 09:18 -0700, Andi Kleen wrote:
quoted
And in general it looks like blind conversion from spinlock to mutex
is a bad idea right now.
For 4 socket machines, maybe. On 2 sockets I cannot reproduce anything.

I wonder if its the fairness thing, the mutex spinners aren't fifo fair
like the ticket locks are. It could be significant with larger socket
count since their cacheline arbitration is more sucky.

Peter,

Wonder if you can provide the profile on your run so I can compare with
what I got on 4 sockets?

Thanks.

Tim

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help