summaryrefslogtreecommitdiffstats
path: root/Documentation/robust-futex-ABI.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/robust-futex-ABI.txt')
-rw-r--r--Documentation/robust-futex-ABI.txt14
1 files changed, 9 insertions, 5 deletions
diff --git a/Documentation/robust-futex-ABI.txt b/Documentation/robust-futex-ABI.txt
index 16eb314f56cc..8a5d34abf726 100644
--- a/Documentation/robust-futex-ABI.txt
+++ b/Documentation/robust-futex-ABI.txt
@@ -1,7 +1,9 @@
-Started by Paul Jackson <pj@sgi.com>
-
+====================
The robust futex ABI
---------------------
+====================
+
+:Author: Started by Paul Jackson <pj@sgi.com>
+
Robust_futexes provide a mechanism that is used in addition to normal
futexes, for kernel assist of cleanup of held locks on task exit.
@@ -32,7 +34,7 @@ probably causing deadlock or other such failure of the other threads
waiting on the same locks.
A thread that anticipates possibly using robust_futexes should first
-issue the system call:
+issue the system call::
asmlinkage long
sys_set_robust_list(struct robust_list_head __user *head, size_t len);
@@ -91,7 +93,7 @@ that lock using the futex mechanism.
When a thread has invoked the above system call to indicate it
anticipates using robust_futexes, the kernel stores the passed in 'head'
pointer for that task. The task may retrieve that value later on by
-using the system call:
+using the system call::
asmlinkage long
sys_get_robust_list(int pid, struct robust_list_head __user **head_ptr,
@@ -135,6 +137,7 @@ manipulating this list), the user code must observe the following
protocol on 'lock entry' insertion and removal:
On insertion:
+
1) set the 'list_op_pending' word to the address of the 'lock entry'
to be inserted,
2) acquire the futex lock,
@@ -143,6 +146,7 @@ On insertion:
4) clear the 'list_op_pending' word.
On removal:
+
1) set the 'list_op_pending' word to the address of the 'lock entry'
to be removed,
2) remove the lock entry for this lock from the 'head' list,