[PATCH] Unify pthread_once (bug 15215)

[Will Newton]

On 7 October 2013 22:53, Torvald Riegel <triegel@redhat.com> wrote:
> On Mon, 2013-10-07 at 16:04 +0000, Joseph S. Myers wrote:
>> I have no comments on the substance of this patch, but note that ports/
>> has a separate ChangeLog file for each architecture.
>
> Sorry. The attached patch now has separate ChangeLog entries for each of
> the affected archs.

There seems to be a significant performance delta on aarch64:

Old code:

"pthread_once": {
"": {
"duration": 9.29471e+09, "iterations": 1.10667e+09, "max": 24.54,
"min": 8.38, "mean": 8.39882

New code:

"pthread_once": {
"": {
"duration": 9.72366e+09, "iterations": 4.33843e+08, "max": 30.86,
"min": 22.38, "mean": 22.4128

And also ARM:

Old code:

"pthread_once": {
"": {
"duration": 8.38662e+09, "iterations": 6.6695e+08, "max": 35.292,
"min": 12.416, "mean": 12.5746

New code:

"pthread_once": {
"": {
"duration": 9.26424e+09, "iterations": 3.07574e+08, "max": 86.125,
"min": 28.875, "mean": 30.1204

It would be nice to understand the source of this variation. I can put
it on my todo list but I can't promise I will be able to look at it
any time soon.

-- 
Will Newton
Toolchain Working Group, Linaro