Re: page table lock patch V15 [0/7]: overview

[Andrew Morton]

Christoph Lameter <clameter@xxxxxxx> wrote:
>
> > Do we have measurements of the negative and/or positive impact on smaller
>  > machines?
> 
>  Here is a measurement of 256M allocation on a 2 way SMP machine 2x
>  PIII-500Mhz:
> 
>   Gb Rep Threads   User      System     Wall flt/cpu/s fault/wsec
>    0  10    1    0.005s      0.016s   0.002s 54357.280  52261.895
>    0  10    2    0.008s      0.019s   0.002s 43112.368  42463.566
> 
>  With patch:
> 
>   Gb Rep Threads   User      System     Wall flt/cpu/s fault/wsec
>    0  10    1    0.005s      0.016s   0.002s 54357.280  53439.357
>    0  10    2    0.008s      0.018s   0.002s 44650.831  44202.412
> 
>  So only a very minor improvements for old machines (this one from ~ 98).

OK.  But have you written a test to demonstrate any performance
regressions?  From, say, the use of atomic ops on ptes?
-
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/