[S390,PPC] Implement FUTEX_WAIT_BITSET for timedwait functions

Since the FUTEX_WAIT operation takes a relative timeout, the
pthread_cond_timedwait and other timed function implementations have
to get a relative timeout from the absolute timeout parameter it gets
before it makes the futex syscall.  This value is then converted back
into an absolute timeout within the kernel.  This is a waste and has
hence been improved upon by a FUTEX_WAIT_BITSET operation (OR'd with
FUTEX_CLOCK_REALTIME to make the kernel use the realtime clock instead
of the default monotonic clock).  This was implemented only in the x86
and sh assembly code and not in the C code.  This patch implements
support for FUTEX_WAIT_BITSET whenever available (since linux-2.6.29)
for s390 and powerpc.

1 files changed, 13 insertions, 0 deletions

diff --git a/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
index 406c290d71..17e63c6901 100644
--- a/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
+++ b/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
@@ -88,6 +88,19 @@
     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;		      \
   })
 
+#define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
+  ({									      \
+    INTERNAL_SYSCALL_DECL (__err);					      \
+    long int __ret;							      \
+    int __op = FUTEX_WAIT_BITSET | clockbit;				      \
+									      \
+    __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		      \
+			      __lll_private_flag (__op, private),	      \
+			      (val), (timespec), NULL /* Unused.  */, 	      \
+			      FUTEX_BITSET_MATCH_ANY);			      \
+    INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;		      \
+  })
+
 #define lll_futex_wake(futexp, nr, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \