Re: [PATCH v1] kernel/trace:check the val against the available mem

[Michal Hocko]

On Wed 04-04-18 08:59:01, Steven Rostedt wrote:
[...]
> +       /*
> +        * Check if the available memory is there first.
> +        * Note, si_mem_available() only gives us a rough estimate of available
> +        * memory. It may not be accurate. But we don't care, we just want
> +        * to prevent doing any allocation when it is obvious that it is
> +        * not going to succeed.
> +        */
> +       i = si_mem_available();
> +       if (i < nr_pages)
> +               return -ENOMEM;
> +
> 
> Better?

I must be really missing something here. How can that work at all for
e.g. the zone_{highmem/movable}. You will get false on the above tests
even when you will have hard time to allocate anything from your
destination zones.
-- 
Michal Hocko
SUSE Labs