[dpdk-dev] add support for HTM lock elision for x86

[Jay Rolette]

On Tue, Jun 2, 2015 at 8:11 AM, Roman Dementiev <roman.dementiev at intel.com>
wrote:

>
> This series of patches adds methods that use hardware memory transactions
> (HTM)
> on fast-path for DPDK locks (a.k.a. lock elision). Here the methods are
> implemented
> for x86 using Restricted Transactional Memory instructions (Intel(r)
> Transactional
> Synchronization Extensions). The implementation fall-backs to the normal
> DPDK lock
> if HTM is not available or memory transactions fail.
>

This is very interesting. Do you have any summary you can give us of what
the performance implications are from your test data?


> This is not a replacement for lock usages since not all critical sections
> protected
> by locks are friendly to HTM.
>

Any pointers to material that describe where HTM in its current incarnation
on x86 is approprate?


>
> Roman Dementiev (3):
>  spinlock: add support for HTM lock elision for x86
>  rwlock: add support for HTM lock elision for x86
>  test scaling of HTM lock elision protecting rte_hash
>
>  app/test/Makefile                                  |   1 +
>  app/test/test_hash_scaling.c                       | 223
> +++++++++++++++++++++
>  lib/librte_eal/common/Makefile                     |   4 +-
>  .../common/include/arch/ppc_64/rte_rwlock.h        |  38 ++++
>  .../common/include/arch/ppc_64/rte_spinlock.h      |  41 ++++
>  lib/librte_eal/common/include/arch/x86/rte_rtm.h   |  73 +++++++
>  .../common/include/arch/x86/rte_rwlock.h           |  82 ++++++++
>  .../common/include/arch/x86/rte_spinlock.h         | 107 ++++++++++
>  lib/librte_eal/common/include/generic/rte_rwlock.h | 194
> ++++++++++++++++++
>  .../common/include/generic/rte_spinlock.h          |  75 +++++++
>  lib/librte_eal/common/include/rte_rwlock.h         | 158 ---------------
>  11 files changed, 836 insertions(+), 160 deletions(-)
>

Thanks!
Jay