[updated patch] malloc per-thread cache ready for review

[Joseph Myers]

On Wed, 5 Jul 2017, DJ Delorie wrote:

> diff -x .git -x po -rup glibc.pristine/NEWS glibc.djmalloc-tcache/NEWS
> --- glibc.pristine/NEWS	2017-06-26 17:13:13.080645103 -0400
> +++ glibc.djmalloc-tcache/NEWS	2017-07-05 15:59:37.735381015 -0400
> @@ -7,6 +7,14 @@ using `glibc' in the "product" field.
>  
>  Version 2.26
>  
> +* A per-thread cache has been added to malloc. Access to the cache requires
> +  no locks and therefore significantly accelerates the fast path to allocate
> +  and free small amounts of memory. Refilling an empty cache requires locking
> +  the underlying arena. Performance measurements show significant gains in a
> +  wide variety of user workloads. Workloads were captured using a special
> +  instrumented malloc and analyzed with a malloc simulator. Contributed by
> +  DJ Delorie with the help of Florian Weimer, and Carlos O'Donell.

To be clear, this belongs in the "Major new features:" section of the 
current NEWS file, which has been rearranged since the version this diff 
is relative to, *not* just below the "Version 2.26" header.

-- 
Joseph S. Myers
joseph@codesourcery.com