path: root/Documentation/futex-requeue-pi.txt
diff options
authorMichael Kerrisk <mtk.manpages@gmail.com>2015-01-16 20:27:57 +0100
committerThomas Gleixner <tglx@linutronix.de>2015-01-19 12:05:32 +0100
commit40a35503401a5a5ffd8bb03b120724e213160584 (patch)
treea5cfbeff14685234b8ef50a2c948b34f5f4d9979 /Documentation/futex-requeue-pi.txt
parenta97af339c80675402d23923f9514491e0a6b5477 (diff)
doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants
FUTEX_CMP_REQUEUE_PI was misnamed in two different ways: FUTEX_REQUEUE_CMP_PI and FUTEX_REQUEUE_PI. The existence of two different misnamings leaves the reader wondering if we are talking about two different operations. Furthermore, the misnamings mean that grepping the source for the correct name (which doesn't appear at all) won't find this documentation file. Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Darren Hart <darren@dvhart.com> Link: http://lkml.kernel.org/r/54B9663D.9070000@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/futex-requeue-pi.txt')
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/futex-requeue-pi.txt b/Documentation/futex-requeue-pi.txt
index 31b16610c416..77b36f59d16b 100644
--- a/Documentation/futex-requeue-pi.txt
+++ b/Documentation/futex-requeue-pi.txt
@@ -98,7 +98,7 @@ rt_mutex_start_proxy_lock() and rt_mutex_finish_proxy_lock(), which
allow the requeue code to acquire an uncontended rt_mutex on behalf
of the waiter and to enqueue the waiter on a contended rt_mutex.
Two new system calls provide the kernel<->user interface to
FUTEX_WAIT_REQUEUE_PI is called by the waiter (pthread_cond_wait()
and pthread_cond_timedwait()) to block on the initial futex and wait
@@ -107,7 +107,7 @@ result of a high-speed collision between futex_wait() and
futex_lock_pi(), with some extra logic to check for the additional
wake-up scenarios.
-FUTEX_REQUEUE_CMP_PI is called by the waker
+FUTEX_CMP_REQUEUE_PI is called by the waker
(pthread_cond_broadcast() and pthread_cond_signal()) to requeue and
possibly wake the waiting tasks. Internally, this system call is
still handled by futex_requeue (by passing requeue_pi=1). Before
@@ -120,12 +120,12 @@ task as a waiter on the underlying rt_mutex. It is possible that
the lock can be acquired at this stage as well, if so, the next
waiter is woken to finish the acquisition of the lock.
-FUTEX_REQUEUE_PI accepts nr_wake and nr_requeue as arguments, but
+FUTEX_CMP_REQUEUE_PI accepts nr_wake and nr_requeue as arguments, but
their sum is all that really matters. futex_requeue() will wake or
requeue up to nr_wake + nr_requeue tasks. It will wake only as many
tasks as it can acquire the lock for, which in the majority of cases
should be 0 as good programming practice dictates that the caller of
either pthread_cond_broadcast() or pthread_cond_signal() acquire the
-mutex prior to making the call. FUTEX_REQUEUE_PI requires that
+mutex prior to making the call. FUTEX_CMP_REQUEUE_PI requires that
nr_wake=1. nr_requeue should be INT_MAX for broadcast and 0 for