Re: [dpdk-dev] [PATCH v1 0/2] reimplement rwlock and add relevant perf test case

[Thomas Monjalon <thomas@monjalon.net>]

17/12/2018 06:16, Honnappa Nagarahalli:
> Adding other platform maintainers as it affects all platforms.

There is no other comment. I am not sure what to do with this patch.


> From: Gavin Hu (Arm Technology China) <Gavin.Hu@arm.com>
> > 
> > Hi Stephen,
> > 
> > Thanks for your comment and sharing the link!
> > We are looking into it and it may take more time for performance profiling.
> > 
> > Best Regards,
> > Gavin
> > 
> > From: Stephen Hemminger <stephen@networkplumber.org>
> > > On Thu, 13 Dec 2018 11:37:43 +0800
> > > Joyce Kong <joyce.kong@arm.com> wrote:
> > >
> > > > v1: reimplement rwlock with __atomic builtins, and add a rwlock perf test
> > > >     on all available cores to benchmark the improvement.
> > > >
> > > > We tested the patches on three arm64 platforms, ThundeX2 gained 20%
> > > > performance, Qualcomm gained 36% and the 4-Cortex-A72 Marvell
> > > MACCHIATObin gained 19.6%.
> > > > Below is the detailed test result on ThunderX2:
> > > >
> > > > *** rwlock_autotest without __atomic builtins *** Rwlock Perf Test
> > > > on
> > > > 128 cores...
> > > > Core [0] count = 281
> > > > Core [1] count = 252
> > > > Core [2] count = 290
> > > > Core [3] count = 259
> > > > Core [4] count = 287
> > > > ...
> > > > Core [209] count = 3
> > > > Core [210] count = 31
> > > > Core [211] count = 120
> > > > Total count = 18537
> > > >
> > > > *** rwlock_autotest with __atomic builtins *** Rwlock Perf Test on
> > > > 128 cores...
> > > > Core [0] count = 346
> > > > Core [1] count = 355
> > > > Core [2] count = 259
> > > > Core [3] count = 285
> > > > Core [4] count = 320
> > > > ...
> > > > Core [209] count = 2
> > > > Core [210] count = 23
> > > > Core [211] count = 63
> > > > Total count = 22194
> > > >
> > > > Gavin Hu (1):
> > > >   rwlock: reimplement with __atomic builtins
> > > >
> > > > Joyce Kong (1):
> > > >   test/rwlock: add perf test case
> > > >
> > > >  lib/librte_eal/common/include/generic/rte_rwlock.h | 16 ++---
> > > >  test/test/test_rwlock.c                            | 71 ++++++++++++++++++++++
> > > >  2 files changed, 79 insertions(+), 8 deletions(-)
> > > >
> > >
> > > Did you consider using a better algorithm not just better primitives.
> > > See https://locklessinc.com/articles/locks/ for a more complete
> > > discussion of alternatives like ticket locks.