Re: [Xen-ia64-devel] [PATCH] [Resend]Enable hash vtlb

[Tristan Gingold <Tristan.Gingold@xxxxxxxx>]

Le Vendredi 07 Avril 2006 21:02, Xu, Anthony a écrit :
> Hash vTLB is intended to address SMP scalability for large system.
I don't really understand this.

From my point of view, your patches add 3 changes:
* VHPT is per VP (and not LP).
* Collision chains
* itc large pages correctly handled.

I won't discuss itc large page.  This bug could be also fixed in the current 
implementation.

I don't think per VP VHPT will improve scalability.  At least not when each LP 
is assigned to only one VCPU.

Collision chains may improve performances.  My only concern is wether or not 
collision chains will well support SMP-g.

This is not a criticism. I am *for* experimented many vTLBs.  I'd just like to 
understand your arguments.

(BTW, I'd prefer a command line option such as vtlb=vp-vhpt or vtlb=lp-vhpt 
rather than a compile-time option).

Tristan.


_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel