Re: PHP performance on Xen domU with mulitple vcpu

[Greg Troxel <gdt%lexort.com@localhost>]

Emmanuel Dreyfus <manu%netbsd.org@localhost> writes:

> On NetBSD-10.0/amd64 Xen domU with two vcpu PHP's uniqid() performance
> is terrible. Theses two tests are on the same dom0, with same NetBSD
> versions in the domU:
>
> With a single vcpu:
> $ time php -r 'for ($i = 0; $i < 1000000; $i++) uniqid();'
>     2.94s real     0.77s user     1.71s system
>
> With two vcpu (note this is only 100 iterations):
> $ time php -r 'for ($i = 0; $i < 100; $i++) uniqid();'  
>    19.10s real     6.13s user     6.39s system

Have you written a test program to log and examined the return values?
Is xen somehow using a timecounter that is incrementing in larger jumps?