[PATCH v3 0/4] Add CLOCK_MONOTONIC support for PI mutexes

[Adhemerval Zanella]

Ping on the set.

On 06/09/2021 17:47, Adhemerval Zanella wrote:
> It adds support for CLOCK_MONOTONIC for PI mutexes by using the new
> Linux v5.14 FUTEX_LOCK_PI2 operation.  Similar to current approach,
> pthread_mutex_clocklock might return EINVAL if the underlying kernel
> has no support for the futex operation.
> 
> Changes since v2:
> 
>   * Renamed xpthread_mutex_pi_support_monotonic to
>     support_mutex_pi_monotonic.
> 
> Changes since v1:
>   
>   * Refactor futex_lock_pi64 and avoid adding futex_lock_pi2.  The
>     FUTEX_LOCK_PI2 logic is done at only one place, so the code change
>     on pthread routines are minimal.  Also, FUTEX_LOCK_PI2 is only
>     used if it is really required, i.e, when a timeout against
>     CLOCK_MONOTONIC is used.
>   * Do not remove nptl/tst-mutexpi10.c, but instead adjust it to new
>     FUTEX_LOCK_PI2 support.
>   * Add pthread_mutex_pi_support_monotonic() to check if monotonic
>     clock with PI mutexes are supported and use on test to check for
>     the expected result.
> 
> Adhemerval Zanella (3):
>   nptl: Use FUTEX_LOCK_PI2 when available
>   support: Add support_mutex_pi_monotonic
>   nptl: Add CLOCK_MONOTONIC support for PI mutexes
> 
> Kurt Kanzenbach (1):
>   Linux: Add FUTEX_LOCK_PI2
> 
>  nptl/futex-internal.c                     | 63 +++++++++++++++++++++++
>  nptl/pthread_mutex_lock.c                 |  3 +-
>  nptl/pthread_mutex_timedlock.c            | 10 +---
>  nptl/tst-mutexpi10.c                      | 42 +++++++++------
>  support/Makefile                          |  1 +
>  support/support_mutex_pi_monotonic.c      | 33 ++++++++++++
>  support/xthread.h                         |  4 ++
>  sysdeps/nptl/futex-internal.h             | 58 ++-------------------
>  sysdeps/nptl/lowlevellock-futex.h         |  1 +
>  sysdeps/pthread/tst-mutex5.c              | 23 ++++++---
>  sysdeps/pthread/tst-mutex9.c              | 20 ++++---
>  sysdeps/unix/sysv/linux/kernel-features.h |  8 +++
>  12 files changed, 172 insertions(+), 94 deletions(-)
>  create mode 100644 support/support_mutex_pi_monotonic.c
>