[PATCH] POSIX clocks & timers

This is version 23 or so of the POSIX timer code.

Internal changelog:

 - Changed the signals code to match the new order of things.  Also the
   new xtime_lock code needed to be picked up.  It made some things a lot
   simpler.

 - Fixed a spin lock hand off problem in locking timers (thanks
   to Randy).

 - Fixed nanosleep to test for out of bound nanoseconds
   (thanks to Julie).

 - Fixed a couple of id deallocation bugs that left old ids
   laying around (hey I get this one).

 - This version has a new timer id manager.  Andrew Morton
   suggested elimination of recursion (done) and I added code
   to allow it to release unused nodes.  The prior version only
   released the leaf nodes.  (The id manager uses radix tree
   type nodes.)  Also added is a reuse count so ids will not
   repeat for at least 256 alloc/ free cycles.

 - The changes for the new sys_call restart now allow one
   restart function to handle both nanosleep and clock_nanosleep.
   Saves a bit of code, nice.

 - All the requested changes and Lindent too :).

 - I also broke clock_nanosleep() apart much the same way
   nanosleep() was with the 2.5.50-bk5 changes.

TIMER STORMS

The POSIX clocks and timers code prevents "timer storms" by
not putting repeating timers back in the timer list until
the signal is delivered for the prior expiry.  Timer events
missed by this delay are accounted for in the timer overrun
count.  The net result is MUCH lower system overhead while
presenting the same info to the user as would be the case if
an interrupt and timer processing were required for each
increment in the overrun count.

1 files changed, 12 insertions, 4 deletions

diff --git a/include/asm-generic/siginfo.h b/include/asm-generic/siginfo.h
index f246b2a15eb5..ddb85a2c7613 100644
--- a/include/asm-generic/siginfo.h
+++ b/include/asm-generic/siginfo.h
@@ -43,8 +43,11 @@ typedef struct siginfo {
 
 		/* POSIX.1b timers */
 		struct {
-			unsigned int _timer1;
-			unsigned int _timer2;
+			timer_t _tid;		/* timer id */
+			int _overrun;		/* overrun count */
+			char _pad[sizeof( __ARCH_SI_UID_T) - sizeof(int)];
+			sigval_t _sigval;	/* same as below */
+			int _sys_private;       /* not to be passed to user */
 		} _timer;
 
 		/* POSIX.1b signals */
@@ -86,8 +89,9 @@ typedef struct siginfo {
  */
 #define si_pid		_sifields._kill._pid
 #define si_uid		_sifields._kill._uid
-#define si_timer1	_sifields._timer._timer1
-#define si_timer2	_sifields._timer._timer2
+#define si_tid		_sifields._timer._tid
+#define si_overrun	_sifields._timer._overrun
+#define si_sys_private  _sifields._timer._sys_private
 #define si_status	_sifields._sigchld._status
 #define si_utime	_sifields._sigchld._utime
 #define si_stime	_sifields._sigchld._stime
@@ -221,6 +225,7 @@ typedef struct siginfo {
 #define SIGEV_SIGNAL	0	/* notify via signal */
 #define SIGEV_NONE	1	/* other notification: meaningless */
 #define SIGEV_THREAD	2	/* deliver via thread creation */
+#define SIGEV_THREAD_ID 4	/* deliver to thread */
 
 #define SIGEV_MAX_SIZE	64
 #ifndef SIGEV_PAD_SIZE
@@ -235,6 +240,7 @@ typedef struct sigevent {
 	int sigev_notify;
 	union {
 		int _pad[SIGEV_PAD_SIZE];
+		 int _tid;
 
 		struct {
 			void (*_function)(sigval_t);
@@ -247,10 +253,12 @@ typedef struct sigevent {
 
 #define sigev_notify_function	_sigev_un._sigev_thread._function
 #define sigev_notify_attributes	_sigev_un._sigev_thread._attribute
+#define sigev_notify_thread_id	 _sigev_un._tid
 
 #ifdef __KERNEL__
 
 struct siginfo;
+void do_schedule_next_timer(struct siginfo *info);
 
 #ifndef HAVE_ARCH_COPY_SIGINFO