This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH][BZ #15988] Fix check for PI mutex on non-x86 systems


On 01-10-2013 06:50, Siddhesh Poyarekar wrote:
> Hi,
>
> Fedora bug report:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1007590
>
> I don't know how I didn't notice this earlier, but tst-mutexpi8 was
> failing on s390 and ppc due to a bug I introduced while adding PI
> mutex support to pthread_cond_* for non-x86 systems.  I had used the
> wrong flag to test against (PTHREAD_MUTEX_ROBUST instead of the
> correct PTHREAD_MUTEX_ROBUST_NORMAL_NP) which broke recursive PI
> mutexes.  The patch below replaces this test with the USE_REQUEUE_PI
> macro.  Tested on s390 and verified that it fixes tst-mutexpi8 and
> also does not introduce any new regressions.  OK to commit?
>
> Siddhesh
>
> 	[BZ #15988]
> 	* pthread_cond_broadcast.c (__pthread_cond_broadcast)
> 	[lll_futex_cmp_requeue_pi && __ASSUME_REQUEUE_PI]: Use
> 	USE_REQUEUE_PI.
> 	* pthread_cond_signal.c (__pthread_cond_signal)
> 	[lll_futex_cmd_requeue_pi && __ASSUME_REQUEUE_PI]: Likewise.
>
> diff --git a/nptl/pthread_cond_broadcast.c b/nptl/pthread_cond_broadcast.c
> index 0702ec0..7ba9efa 100644
> --- a/nptl/pthread_cond_broadcast.c
> +++ b/nptl/pthread_cond_broadcast.c
> @@ -63,10 +63,7 @@ __pthread_cond_broadcast (cond)
>
>  #if (defined lll_futex_cmp_requeue_pi \
>       && defined __ASSUME_REQUEUE_PI)
> -      int pi_flag = PTHREAD_MUTEX_PRIO_INHERIT_NP | PTHREAD_MUTEX_ROBUST_NP;
> -      pi_flag &= mut->__data.__kind;
> -
> -      if (pi_flag == PTHREAD_MUTEX_PRIO_INHERIT_NP)
> +      if (USE_REQUEUE_PI (mut))
>  	{
>  	  if (lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, INT_MAX,
>  					&mut->__data.__lock, futex_val,
> diff --git a/nptl/pthread_cond_signal.c b/nptl/pthread_cond_signal.c
> index 102d0b3..ffc35dc 100644
> --- a/nptl/pthread_cond_signal.c
> +++ b/nptl/pthread_cond_signal.c
> @@ -49,14 +49,9 @@ __pthread_cond_signal (cond)
>
>  #if (defined lll_futex_cmp_requeue_pi \
>       && defined __ASSUME_REQUEUE_PI)
> -      int pi_flag = PTHREAD_MUTEX_PRIO_INHERIT_NP | PTHREAD_MUTEX_ROBUST_NP;
>        pthread_mutex_t *mut = cond->__data.__mutex;
>
> -      /* Do not use requeue for pshared condvars.  */
> -      if (mut != (void *) ~0l)
> -	pi_flag &= mut->__data.__kind;
> -
> -      if (__builtin_expect (pi_flag == PTHREAD_MUTEX_PRIO_INHERIT_NP, 0)
> +      if (USE_REQUEUE_PI (mut)
>  	/* This can only really fail with a ENOSYS, since nobody can modify
>  	   futex while we have the cond_lock.  */
>  	  && lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, 0,
>
Thanks for fixing it, I was chasint this issue too. I'm ok with this patch.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]