[RFC PATCH 3/4] Test pidns translation cache

Dmitry V. Levin ldv at altlinux.org
Sat Aug 15 12:37:42 UTC 2020


On Thu, Aug 13, 2020 at 05:32:41PM +0200, Ákos Uzonyi wrote:
[...]
> +/**
> + * There is a 1 sec timeout for this test. With pidns caching more than 1000
> + * syscalls can be executed, without caching only a few tens.
> + */
> +#define SYSCALL_COUNT 200
> +
> +int
> +main(void)
> +{
> +	pidns_test_init();
> +
> +        for (int i = 0; i < SYSCALL_COUNT; i++)
> +                getpid();
> +
> +	return 0;
> +}

As getpid can be easily cached by libc, this has to be a syscall().

With regards to the number of syscalls, some hosts could be very slow, so
I suggest to count the number of syscalls without any pid translation and
use it as a baseline.


-- 
ldv


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