[PATCH 2/2] Document the M_ARENA_* mallopt parameters

[DJ Delorie]

Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> -/*  Non public mallopt parameters.  */
>  #define M_ARENA_TEST -7
>  #define M_ARENA_MAX  -8

Hmmm... if these are now public, do they need to be moved elsewhere?
Like, malloc.h ?

> +The presence of multiple @code{arenas} allows multiple threads to allocate
> +memory simultaneously in their own separate arenas, thus improving performance.

Not quite true - there isn't one arena per thread, there are N arenas
per M threads.  Probably better to say "... simultaneously in separate
arenas ..."

> +environment variable @code{MALLOC_ARENA_TEST} to the desired value.
> +@item M_ARENA_MAX

Missing blank line.

Otherwise, the content looks OK to me from a technical point of view.