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SubjectRe: [PATCH] alternate Posix timer patch
Jim Houston wrote:
>
> Hi Everyone,
>
> This is the second version of my spin on the Posix timers. I started
> with George Anzinger's patch but I have made major changes.
>
> I have been using George's version of the patch and would be glad to
> see it included into the 2.5 tree. On the other hand since we don't
> know what might appeal to Linus it makes sense to give him a choice.
>
> I sent out the first version of this last friday and had useful
> coments from Andi Kleen. I have addressed some of these but mostly
> I have just been getting it to work. It now passes most of the
> tests that are included in George's timers support package.
>
> Of particular interest is a race (that Andi pointed out) between
> saving a task_struct pointer, using this pointer to send signals
> and the process exiting. George please look at my changes in
> sys_timer_create and exit_itimer.

Yes, I have looked and agree with your changes. They will
be in the next version, hopefully today.

I have also looked at the timer index stuff and made a few
changes. If it get it working today, I will include it
also. My changes mostly revolved around not caring about
reusing a timer id. Would you care to comment on why you
think reuse is bad?

With out this feature the code is much simpler and does not
keep around dead trees.

-g


>
> Here is a summary of my changes:
>
> - A new queue just for Posix timers and code to
> handle expiring timers. This supports high resolution
> without having to change the existing jiffie based timers.
>
> I implemented this priority queue as a sort list
> with a rbtree to index the list. It is deterministic
> and fast.
>
> - Change to use the slab allocator. This removes
> the CONFIG option for the maximum number of timers.
>
> - A new id allocator/lookup mechanism based on a
> radix tree. It includes a bitmap to summarize the portion
> of the tree which is in use. Currently the Posix
> timers patch reuses the id immediately.
>
> - I keep the timers in seconds and nano-seconds.
> I'm hoping that the system time keeping will sort
> itself out and the Posix timers can just be a consumer.
> Posix timers need two clocks - the time since boot and
> the wall clock time.
>
> I'm currently working on nanosleep. I'm trying to come up with an
> alternative for the call to do_signal. At the moment my patch may
> return from nanosleep early if it receives a debug signal.
>
> This patch should work with linux- 2.5.44.
>
> Jim Houston - Concurrent Computer Corp.
>
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/arch/i386/kernel/entry.S linux.mytimers/arch/i386/kernel/entry.S
> --- linux.orig/arch/i386/kernel/entry.S Wed Oct 23 00:54:19 2002
> +++ linux.mytimers/arch/i386/kernel/entry.S Wed Oct 23 01:17:51 2002
> @@ -737,6 +737,15 @@
> .long sys_free_hugepages
> .long sys_exit_group
> .long sys_lookup_dcookie
> + .long sys_timer_create
> + .long sys_timer_settime /* 255 */
> + .long sys_timer_gettime
> + .long sys_timer_getoverrun
> + .long sys_timer_delete
> + .long sys_clock_settime
> + .long sys_clock_gettime /* 260 */
> + .long sys_clock_getres
> + .long sys_clock_nanosleep
>
> .rept NR_syscalls-(.-sys_call_table)/4
> .long sys_ni_syscall
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/arch/i386/kernel/time.c linux.mytimers/arch/i386/kernel/time.c
> --- linux.orig/arch/i386/kernel/time.c Wed Oct 23 00:54:19 2002
> +++ linux.mytimers/arch/i386/kernel/time.c Wed Oct 23 01:17:51 2002
> @@ -131,6 +131,7 @@
> time_maxerror = NTP_PHASE_LIMIT;
> time_esterror = NTP_PHASE_LIMIT;
> write_unlock_irq(&xtime_lock);
> + clock_was_set();
> }
>
> /*
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/fs/exec.c linux.mytimers/fs/exec.c
> --- linux.orig/fs/exec.c Wed Oct 23 00:54:21 2002
> +++ linux.mytimers/fs/exec.c Wed Oct 23 01:37:27 2002
> @@ -756,6 +756,7 @@
>
> flush_signal_handlers(current);
> flush_old_files(current->files);
> + exit_itimers(current, 0);
>
> return 0;
>
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/asm-generic/siginfo.h linux.mytimers/include/asm-generic/siginfo.h
> --- linux.orig/include/asm-generic/siginfo.h Wed Oct 23 00:54:24 2002
> +++ linux.mytimers/include/asm-generic/siginfo.h Wed Oct 23 01:17:51 2002
> @@ -43,8 +43,9 @@
>
> /* POSIX.1b timers */
> struct {
> - unsigned int _timer1;
> - unsigned int _timer2;
> + timer_t _tid; /* timer id */
> + int _overrun; /* overrun count */
> + sigval_t _sigval; /* same as below */
> } _timer;
>
> /* POSIX.1b signals */
> @@ -86,8 +87,8 @@
> */
> #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_status _sifields._sigchld._status
> #define si_utime _sifields._sigchld._utime
> #define si_stime _sifields._sigchld._stime
> @@ -221,6 +222,7 @@
> #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 +237,7 @@
> int sigev_notify;
> union {
> int _pad[SIGEV_PAD_SIZE];
> + int _tid;
>
> struct {
> void (*_function)(sigval_t);
> @@ -247,6 +250,7 @@
>
> #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__
>
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/asm-i386/posix_types.h linux.mytimers/include/asm-i386/posix_types.h
> --- linux.orig/include/asm-i386/posix_types.h Tue Jan 18 01:22:52 2000
> +++ linux.mytimers/include/asm-i386/posix_types.h Wed Oct 23 01:17:51 2002
> @@ -22,6 +22,8 @@
> typedef long __kernel_time_t;
> typedef long __kernel_suseconds_t;
> typedef long __kernel_clock_t;
> +typedef int __kernel_timer_t;
> +typedef int __kernel_clockid_t;
> typedef int __kernel_daddr_t;
> typedef char * __kernel_caddr_t;
> typedef unsigned short __kernel_uid16_t;
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/asm-i386/signal.h linux.mytimers/include/asm-i386/signal.h
> --- linux.orig/include/asm-i386/signal.h Wed Oct 23 00:50:41 2002
> +++ linux.mytimers/include/asm-i386/signal.h Wed Oct 23 01:17:51 2002
> @@ -219,6 +219,73 @@
>
> struct pt_regs;
> extern int FASTCALL(do_signal(struct pt_regs *regs, sigset_t *oldset));
> +/*
> + * These macros are used by nanosleep() and clock_nanosleep().
> + * The issue is that these functions need the *regs pointer which is
> + * passed in different ways by the differing archs.
> +
> + * Below we do things in two differing ways. In the long run we would
> + * like to see nano_sleep() go away (glibc should call clock_nanosleep
> + * much as we do). When that happens and the nano_sleep() system
> + * call entry is retired, there will no longer be any real need for
> + * sys_nanosleep() so the FOLD_NANO_SLEEP_INTO_CLOCK_NANO_SLEEP macro
> + * could be undefined, resulting in not needing to stack all the
> + * parms over again, i.e. better (faster AND smaller) code.
> +
> + * And while were at it, there needs to be a way to set the return code
> + * on the way to do_signal(). It (i.e. do_signal()) saves the regs on
> + * the callers stack to call the user handler and then the return is
> + * done using those registers. This means that the error code MUST be
> + * set in the register PRIOR to calling do_signal(). See our answer
> + * below...thanks to Jim Houston <jim.houston@attbi.com>
> + */
> +#define FOLD_NANO_SLEEP_INTO_CLOCK_NANO_SLEEP
> +
> +
> +#ifdef FOLD_NANO_SLEEP_INTO_CLOCK_NANO_SLEEP
> +extern long do_clock_nanosleep(struct pt_regs *regs,
> + clockid_t which_clock,
> + int flags,
> + const struct timespec *rqtp,
> + struct timespec *rmtp);
> +
> +#define NANOSLEEP_ENTRY(a) \
> + asmlinkage long sys_nanosleep( struct timespec* rqtp, \
> + struct timespec * rmtp) \
> +{ struct pt_regs *regs = (struct pt_regs *)&rqtp; \
> + return do_clock_nanosleep(regs, CLOCK_REALTIME, 0, rqtp, rmtp); \
> +}
> +
> +#define CLOCK_NANOSLEEP_ENTRY(a) asmlinkage long sys_clock_nanosleep( \
> + clockid_t which_clock, \
> + int flags, \
> + const struct timespec *rqtp, \
> + struct timespec *rmtp) \
> +{ struct pt_regs *regs = (struct pt_regs *)&which_clock; \
> + return do_clock_nanosleep(regs, which_clock, flags, rqtp, rmtp); \
> +} \
> +long do_clock_nanosleep(struct pt_regs *regs, \
> + clockid_t which_clock, \
> + int flags, \
> + const struct timespec *rqtp, \
> + struct timespec *rmtp) \
> +{ a
> +
> +#else
> +#define NANOSLEEP_ENTRY(a) \
> + asmlinkage long sys_nanosleep( struct timespec* rqtp, \
> + struct timespec * rmtp) \
> +{ struct pt_regs *regs = (struct pt_regs *)&rqtp; \
> + a
> +#define CLOCK_NANOSLEEP_ENTRY(a) asmlinkage long sys_clock_nanosleep( \
> + clockid_t which_clock, \
> + int flags, \
> + const struct timespec *rqtp, \
> + struct timespec *rmtp) \
> +{ struct pt_regs *regs = (struct pt_regs *)&which_clock; \
> + a
> +#endif
> +#define _do_signal() (regs->eax = -EINTR, do_signal(regs, NULL))
>
> #endif /* __KERNEL__ */
>
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/asm-i386/unistd.h linux.mytimers/include/asm-i386/unistd.h
> --- linux.orig/include/asm-i386/unistd.h Wed Oct 23 00:54:21 2002
> +++ linux.mytimers/include/asm-i386/unistd.h Wed Oct 23 01:17:51 2002
> @@ -258,6 +258,15 @@
> #define __NR_free_hugepages 251
> #define __NR_exit_group 252
> #define __NR_lookup_dcookie 253
> +#define __NR_timer_create 254
> +#define __NR_timer_settime (__NR_timer_create+1)
> +#define __NR_timer_gettime (__NR_timer_create+2)
> +#define __NR_timer_getoverrun (__NR_timer_create+3)
> +#define __NR_timer_delete (__NR_timer_create+4)
> +#define __NR_clock_settime (__NR_timer_create+5)
> +#define __NR_clock_gettime (__NR_timer_create+6)
> +#define __NR_clock_getres (__NR_timer_create+7)
> +#define __NR_clock_nanosleep (__NR_timer_create+8)
>
>
> /* user-visible error numbers are in the range -1 - -124: see <asm-i386/errno.h> */
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/id2ptr.h linux.mytimers/include/linux/id2ptr.h
> --- linux.orig/include/linux/id2ptr.h Wed Dec 31 19:00:00 1969
> +++ linux.mytimers/include/linux/id2ptr.h Wed Oct 23 01:25:23 2002
> @@ -0,0 +1,47 @@
> +/*
> + * include/linux/id2ptr.h
> + *
> + * 2002-10-18 written by Jim Houston jim.houston@ccur.com
> + * Copyright (C) 2002 by Concurrent Computer Corporation
> + * Distributed under the GNU GPL license version 2.
> + *
> + * Small id to pointer translation service avoiding fixed sized
> + * tables.
> + */
> +
> +#define ID_BITS 5
> +#define ID_MASK ((1 << ID_BITS)-1)
> +#define ID_FULL ((1 << (1 << ID_BITS))-1)
> +
> +/* Number of id_layer structs to leave in free list */
> +#define ID_FREE_MAX 6
> +
> +struct id_layer {
> + unsigned int bitmap;
> + struct id_layer *ary[1<<ID_BITS];
> +};
> +
> +struct id {
> + int layers;
> + int last;
> + int count;
> + int min_wrap;
> + struct id_layer *top;
> +};
> +
> +void *id2ptr_lookup(struct id *idp, int id);
> +int id2ptr_new(struct id *idp, void *ptr);
> +void id2ptr_remove(struct id *idp, int id);
> +void id2ptr_init(struct id *idp, int min_wrap);
> +
> +
> +static inline void update_bitmap(struct id_layer *p, int bit)
> +{
> + if (p->ary[bit] && p->ary[bit]->bitmap == 0xffffffff)
> + p->bitmap |= 1<<bit;
> + else
> + p->bitmap &= ~(1<<bit);
> +}
> +
> +extern kmem_cache_t *id_layer_cache;
> +
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/init_task.h linux.mytimers/include/linux/init_task.h
> --- linux.orig/include/linux/init_task.h Wed Oct 23 00:54:03 2002
> +++ linux.mytimers/include/linux/init_task.h Wed Oct 23 01:17:51 2002
> @@ -93,6 +93,7 @@
> .sig = &init_signals, \
> .pending = { NULL, &tsk.pending.head, {{0}}}, \
> .blocked = {{0}}, \
> + .posix_timers = LIST_HEAD_INIT(tsk.posix_timers), \
> .alloc_lock = SPIN_LOCK_UNLOCKED, \
> .switch_lock = SPIN_LOCK_UNLOCKED, \
> .journal_info = NULL, \
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/posix-timers.h linux.mytimers/include/linux/posix-timers.h
> --- linux.orig/include/linux/posix-timers.h Wed Dec 31 19:00:00 1969
> +++ linux.mytimers/include/linux/posix-timers.h Wed Oct 23 01:25:02 2002
> @@ -0,0 +1,81 @@
> +/*
> + * include/linux/posix-timers.h
> + *
> + * 2002-10-22 written by Jim Houston jim.houston@ccur.com
> + * Copyright (C) 2002 by Concurrent Computer Corporation
> + * Distributed under the GNU GPL license version 2.
> + *
> + */
> +
> +#ifndef _linux_POSIX_TIMERS_H
> +#define _linux_POSIX_TIMERS_H
> +
> +/* This should be in posix-timers.h - but this is easier now. */
> +
> +enum timer_type {
> + TIMER,
> + NANOSLEEP
> +};
> +
> +struct k_itimer {
> + struct list_head it_pq_list; /* fields for timer priority queue. */
> + struct rb_node it_pq_node;
> + struct timer_pq *it_pq; /* pointer to the queue. */
> +
> + struct list_head it_task_list; /* list for exit_itimers */
> + spinlock_t it_lock;
> + clockid_t it_clock; /* which timer type */
> + timer_t it_id; /* timer id */
> + int it_overrun; /* overrun on pending signal */
> + int it_overrun_last; /* overrun on last delivered signal */
> + int it_overrun_deferred; /* overrun on pending timer interrupt */
> + int it_sigev_notify; /* notify word of sigevent struct */
> + int it_sigev_signo; /* signo word of sigevent struct */
> + sigval_t it_sigev_value; /* value word of sigevent struct */
> + struct task_struct *it_process; /* process to send signal to */
> + struct itimerspec it_v; /* expiry time & interval */
> + enum timer_type it_type;
> +};
> +
> +/*
> + * The priority queue is a sorted doubly linked list ordered by
> + * expiry time. A rbtree is used as an index in to this list
> + * so that inserts are O(log2(n)).
> + */
> +
> +struct timer_pq {
> + struct list_head head;
> + struct rb_root rb_root;
> +};
> +
> +#define TIMER_PQ_INIT(name) { \
> + .rb_root = RB_ROOT, \
> + .head = LIST_HEAD_INIT(name.head), \
> +}
> +
> +
> +#if 0
> +#include <linux/posix-timers.h>
> +#endif
> +
> +struct k_clock {
> + struct timer_pq pq;
> + int res; /* in nano seconds */
> + int ( *clock_set)(struct timespec *tp);
> + int ( *clock_get)(struct timespec *tp);
> + int ( *nsleep)( int flags,
> + struct timespec*new_setting,
> + struct itimerspec *old_setting);
> + int ( *timer_set)(struct k_itimer *timr, int flags,
> + struct itimerspec *new_setting,
> + struct itimerspec *old_setting);
> + int ( *timer_del)(struct k_itimer *timr);
> + void ( *timer_get)(struct k_itimer *timr,
> + struct itimerspec *cur_setting);
> +};
> +
> +int do_posix_clock_monotonic_gettime(struct timespec *tp);
> +int do_posix_clock_monotonic_settime(struct timespec *tp);
> +asmlinkage int sys_timer_delete(timer_t timer_id);
> +
> +#endif
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/sched.h linux.mytimers/include/linux/sched.h
> --- linux.orig/include/linux/sched.h Wed Oct 23 00:54:28 2002
> +++ linux.mytimers/include/linux/sched.h Wed Oct 23 01:31:41 2002
> @@ -29,6 +29,7 @@
> #include <linux/compiler.h>
> #include <linux/completion.h>
> #include <linux/pid.h>
> +#include <linux/posix-timers.h>
>
> struct exec_domain;
>
> @@ -333,6 +334,8 @@
> unsigned long it_real_value, it_prof_value, it_virt_value;
> unsigned long it_real_incr, it_prof_incr, it_virt_incr;
> struct timer_list real_timer;
> + struct list_head posix_timers; /* POSIX.1b Interval Timers */
> + struct k_itimer nanosleep_tmr;
> unsigned long utime, stime, cutime, cstime;
> unsigned long start_time;
> long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS];
> @@ -637,6 +640,7 @@
>
> extern void exit_mm(struct task_struct *);
> extern void exit_files(struct task_struct *);
> +extern void exit_itimers(struct task_struct *, int);
> extern void exit_sighand(struct task_struct *);
> extern void __exit_sighand(struct task_struct *);
>
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/signal.h linux.mytimers/include/linux/signal.h
> --- linux.orig/include/linux/signal.h Wed Oct 23 00:53:01 2002
> +++ linux.mytimers/include/linux/signal.h Wed Oct 23 01:17:51 2002
> @@ -224,6 +224,36 @@
> struct pt_regs;
> extern int get_signal_to_deliver(siginfo_t *info, struct pt_regs *regs);
> #endif
> +/*
> + * We would like the asm/signal.h code to define these so that the using
> + * function can call do_signal(). In loo of that, we define a genaric
> + * version that pretends that do_signal() was called and delivered a signal.
> + * To see how this is used, see nano_sleep() in timer.c and the i386 version
> + * in asm_i386/signal.h.
> + */
> +#ifndef PT_REGS_ENTRY
> +#define PT_REGS_ENTRY(type,name,p1_type,p1, p2_type,p2) \
> +type name(p1_type p1,p2_type p2)\
> +{
> +#endif
> +#ifndef _do_signal
> +#define _do_signal() 1
> +#endif
> +#ifndef NANOSLEEP_ENTRY
> +#define NANOSLEEP_ENTRY(a) asmlinkage long sys_nanosleep( struct timespec* rqtp, \
> + struct timespec * rmtp) \
> +{ a
> +#endif
> +#ifndef CLOCK_NANOSLEEP_ENTRY
> +#define CLOCK_NANOSLEEP_ENTRY(a) asmlinkage long sys_clock_nanosleep( \
> + clockid_t which_clock, \
> + int flags, \
> + const struct timespec *rqtp, \
> + struct timespec *rmtp) \
> +{ a
> +
> +#endif
> +
>
> #endif /* __KERNEL__ */
>
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/sys.h linux.mytimers/include/linux/sys.h
> --- linux.orig/include/linux/sys.h Sun Dec 10 23:56:37 1995
> +++ linux.mytimers/include/linux/sys.h Wed Oct 23 01:17:51 2002
> @@ -4,7 +4,7 @@
> /*
> * system call entry points ... but not all are defined
> */
> -#define NR_syscalls 256
> +#define NR_syscalls 275
>
> /*
> * These are system calls that will be removed at some time
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/time.h linux.mytimers/include/linux/time.h
> --- linux.orig/include/linux/time.h Wed Oct 23 00:53:34 2002
> +++ linux.mytimers/include/linux/time.h Wed Oct 23 01:17:51 2002
> @@ -38,6 +38,19 @@
> */
> #define MAX_JIFFY_OFFSET ((~0UL >> 1)-1)
>
> +/* Parameters used to convert the timespec values */
> +#ifndef USEC_PER_SEC
> +#define USEC_PER_SEC (1000000L)
> +#endif
> +
> +#ifndef NSEC_PER_SEC
> +#define NSEC_PER_SEC (1000000000L)
> +#endif
> +
> +#ifndef NSEC_PER_USEC
> +#define NSEC_PER_USEC (1000L)
> +#endif
> +
> static __inline__ unsigned long
> timespec_to_jiffies(struct timespec *value)
> {
> @@ -124,6 +137,8 @@
> #ifdef __KERNEL__
> extern void do_gettimeofday(struct timeval *tv);
> extern void do_settimeofday(struct timeval *tv);
> +extern int do_sys_settimeofday(struct timeval *tv, struct timezone *tz);
> +extern void clock_was_set(void); // call when ever the clock is set
> #endif
>
> #define FD_SETSIZE __FD_SETSIZE
> @@ -149,5 +164,25 @@
> struct timeval it_interval; /* timer interval */
> struct timeval it_value; /* current value */
> };
> +
> +
> +/*
> + * The IDs of the various system clocks (for POSIX.1b interval timers).
> + */
> +#define CLOCK_REALTIME 0
> +#define CLOCK_MONOTONIC 1
> +#define CLOCK_PROCESS_CPUTIME_ID 2
> +#define CLOCK_THREAD_CPUTIME_ID 3
> +#define CLOCK_REALTIME_HR 4
> +#define CLOCK_MONOTONIC_HR 5
> +
> +#define MAX_CLOCKS 6
> +
> +/*
> + * The various flags for setting POSIX.1b interval timers.
> + */
> +
> +#define TIMER_ABSTIME 0x01
> +
>
> #endif
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/include/linux/types.h linux.mytimers/include/linux/types.h
> --- linux.orig/include/linux/types.h Wed Oct 23 00:54:17 2002
> +++ linux.mytimers/include/linux/types.h Wed Oct 23 01:17:51 2002
> @@ -23,6 +23,8 @@
> typedef __kernel_daddr_t daddr_t;
> typedef __kernel_key_t key_t;
> typedef __kernel_suseconds_t suseconds_t;
> +typedef __kernel_timer_t timer_t;
> +typedef __kernel_clockid_t clockid_t;
>
> #ifdef __KERNEL__
> typedef __kernel_uid32_t uid_t;
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/init/Config.help linux.mytimers/init/Config.help
> --- linux.orig/init/Config.help Wed Oct 23 00:50:42 2002
> +++ linux.mytimers/init/Config.help Wed Oct 23 01:17:51 2002
> @@ -115,3 +115,11 @@
> replacement for kerneld.) Say Y here and read about configuring it
> in <file:Documentation/kmod.txt>.
>
> +Maximum number of POSIX timers
> +CONFIG_MAX_POSIX_TIMERS
> + This option allows you to configure the system wide maximum number of
> + POSIX timers. Timers are allocated as needed so the only memory
> + overhead this adds is about 4 bytes for every 50 or so timers to keep
> + track of each block of timers. The system quietly rounds this number
> + up to fill out a timer allocation block. It is ok to have several
> + thousand timers as needed by your applications.
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/init/Config.in linux.mytimers/init/Config.in
> --- linux.orig/init/Config.in Wed Oct 23 00:50:45 2002
> +++ linux.mytimers/init/Config.in Wed Oct 23 01:17:51 2002
> @@ -9,6 +9,7 @@
> bool 'System V IPC' CONFIG_SYSVIPC
> bool 'BSD Process Accounting' CONFIG_BSD_PROCESS_ACCT
> bool 'Sysctl support' CONFIG_SYSCTL
> +int 'System wide maximum number of POSIX timers' CONFIG_MAX_POSIX_TIMERS 3000
> endmenu
>
> mainmenu_option next_comment
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/Makefile linux.mytimers/kernel/Makefile
> --- linux.orig/kernel/Makefile Wed Oct 23 00:54:21 2002
> +++ linux.mytimers/kernel/Makefile Wed Oct 23 01:24:01 2002
> @@ -10,7 +10,7 @@
> module.o exit.o itimer.o time.o softirq.o resource.o \
> sysctl.o capability.o ptrace.o timer.o user.o \
> signal.o sys.o kmod.o workqueue.o futex.o platform.o pid.o \
> - rcupdate.o
> + rcupdate.o posix-timers.o id2ptr.o
>
> obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
> obj-$(CONFIG_SMP) += cpu.o
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/exit.c linux.mytimers/kernel/exit.c
> --- linux.orig/kernel/exit.c Wed Oct 23 00:54:21 2002
> +++ linux.mytimers/kernel/exit.c Wed Oct 23 01:22:00 2002
> @@ -647,6 +647,7 @@
> __exit_files(tsk);
> __exit_fs(tsk);
> exit_namespace(tsk);
> + exit_itimers(tsk, 1);
> exit_thread();
>
> if (current->leader)
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/fork.c linux.mytimers/kernel/fork.c
> --- linux.orig/kernel/fork.c Wed Oct 23 00:54:17 2002
> +++ linux.mytimers/kernel/fork.c Wed Oct 23 01:17:51 2002
> @@ -783,6 +783,7 @@
> goto bad_fork_cleanup_files;
> if (copy_sighand(clone_flags, p))
> goto bad_fork_cleanup_fs;
> + INIT_LIST_HEAD(&p->posix_timers);
> if (copy_mm(clone_flags, p))
> goto bad_fork_cleanup_sighand;
> if (copy_namespace(clone_flags, p))
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/id2ptr.c linux.mytimers/kernel/id2ptr.c
> --- linux.orig/kernel/id2ptr.c Wed Dec 31 19:00:00 1969
> +++ linux.mytimers/kernel/id2ptr.c Wed Oct 23 01:23:24 2002
> @@ -0,0 +1,223 @@
> +/*
> + * linux/kernel/id2ptr.c
> + *
> + * 2002-10-18 written by Jim Houston jim.houston@ccur.com
> + * Copyright (C) 2002 by Concurrent Computer Corporation
> + * Distributed under the GNU GPL license version 2.
> + *
> + * Small id to pointer translation service.
> + *
> + * It uses a radix tree like structure as a sparse array indexed
> + * by the id to obtain the pointer. A bit map is included in each
> + * level of the tree which identifies portions of the tree which
> + * are completely full. This makes the process of allocating a
> + * new id quick.
> + */
> +
> +
> +#include <linux/slab.h>
> +#include <linux/id2ptr.h>
> +#include <linux/init.h>
> +#include <linux/string.h>
> +
> +static kmem_cache_t *id_layer_cache;
> +spinlock_t id_lock = SPIN_LOCK_UNLOCKED;
> +
> +/*
> + * Since we can't allocate memory with spinlock held and dropping the
> + * lock to allocate gets ugly keep a free list which will satisfy the
> + * worst case allocation.
> + */
> +
> +struct id_layer *id_free;
> +int id_free_cnt;
> +
> +static inline struct id_layer *alloc_layer(void)
> +{
> + struct id_layer *p;
> +
> + if (!(p = id_free))
> + BUG();
> + id_free = p->ary[0];
> + id_free_cnt--;
> + p->ary[0] = 0;
> + return(p);
> +}
> +
> +static inline void free_layer(struct id_layer *p)
> +{
> + p->ary[0] = id_free;
> + id_free = p;
> + id_free_cnt++;
> +}
> +
> +/*
> + * Lookup the kernel pointer associated with a user supplied
> + * id value.
> + */
> +void *id2ptr_lookup(struct id *idp, int id)
> +{
> + int n;
> + struct id_layer *p;
> +
> + if (id <= 0)
> + return(NULL);
> + id--;
> + spin_lock_irq(&id_lock);
> + n = idp->layers * ID_BITS;
> + p = idp->top;
> + if (id >= (1 << n)) {
> + spin_unlock_irq(&id_lock);
> + return(NULL);
> + }
> +
> + while (n > 0 && p) {
> + n -= ID_BITS;
> + p = p->ary[(id >> n) & ID_MASK];
> + }
> + spin_unlock_irq(&id_lock);
> + return((void *)p);
> +}
> +
> +static int sub_alloc(struct id_layer *p, int shift, int id, void *ptr)
> +{
> + int n = (id >> shift) & ID_MASK;
> + int bitmap = p->bitmap;
> + int id_base = id & ~((1 << (shift+ID_BITS))-1);
> + int v;
> +
> + for ( ; n <= ID_MASK; n++, id = id_base + (n << shift)) {
> + if (bitmap & (1 << n))
> + continue;
> + if (shift == 0) {
> + p->ary[n] = (struct id_layer *)ptr;
> + p->bitmap |= 1<<n;
> + return(id);
> + }
> + if (!p->ary[n])
> + p->ary[n] = alloc_layer();
> + if ((v = sub_alloc(p->ary[n], shift-ID_BITS, id, ptr))) {
> + update_bitmap(p, n);
> + return(v);
> + }
> + }
> + return(0);
> +}
> +
> +/*
> + * Allocate a new id associate the value ptr with this new id.
> + */
> +int id2ptr_new(struct id *idp, void *ptr)
> +{
> + int n, last, id, v;
> + struct id_layer *new;
> +
> + spin_lock_irq(&id_lock);
> + n = idp->layers * ID_BITS;
> + last = idp->last;
> + while (id_free_cnt < n+1) {
> + spin_unlock_irq(&id_lock);
> + new = kmem_cache_alloc(id_layer_cache, GFP_KERNEL);
> + memset(new, 0, sizeof(struct id_layer));
> + spin_lock_irq(&id_lock);
> + free_layer(new);
> + }
> + /*
> + * Add a new layer if the array is full or the last id
> + * was at the limit and we don't want to wrap.
> + */
> + if ((last == ((1 << n)-1) && last < idp->min_wrap) ||
> + idp->count == (1 << n)) {
> + ++idp->layers;
> + n += ID_BITS;
> + new = alloc_layer();
> + new->ary[0] = idp->top;
> + idp->top = new;
> + update_bitmap(new, 0);
> + }
> + if (last >= ((1 << n)-1))
> + last = 0;
> +
> + /*
> + * Search for a free id starting after last id allocated.
> + * If that fails wrap back to start.
> + */
> + id = last+1;
> + if (!(v = sub_alloc(idp->top, n-ID_BITS, id, ptr)))
> + v = sub_alloc(idp->top, n-ID_BITS, 1, ptr);
> + idp->last = v;
> + idp->count++;
> + spin_unlock_irq(&id_lock);
> + return(v+1);
> +}
> +
> +
> +static int sub_remove(struct id_layer *p, int shift, int id)
> +{
> + int n = (id >> shift) & ID_MASK;
> + int i, bitmap, rv;
> +
> + rv = 0;
> + bitmap = p->bitmap & ~(1<<n);
> + p->bitmap = bitmap;
> + if (shift == 0) {
> + p->ary[n] = NULL;
> + rv = !bitmap;
> + } else {
> + if (sub_remove(p->ary[n], shift-ID_BITS, id)) {
> + free_layer(p->ary[n]);
> + p->ary[n] = 0;
> + for (i = 0; i < (1 << ID_BITS); i++)
> + if (p->ary[i])
> + break;
> + if (i == (1 << ID_BITS))
> + rv = 1;
> + }
> + }
> + return(rv);
> +}
> +
> +/*
> + * Remove (free) an id value and break the association with
> + * the kernel pointer.
> + */
> +void id2ptr_remove(struct id *idp, int id)
> +{
> + struct id_layer *p;
> +
> + if (id <= 0)
> + return;
> + id--;
> + spin_lock_irq(&id_lock);
> + sub_remove(idp->top, (idp->layers-1)*ID_BITS, id);
> + idp->count--;
> + if (id_free_cnt >= ID_FREE_MAX) {
> +
> + p = alloc_layer();
> + spin_unlock_irq(&id_lock);
> + kmem_cache_free(id_layer_cache, p);
> + return;
> + }
> + spin_unlock_irq(&id_lock);
> +}
> +
> +void init_id_cache(void)
> +{
> + if (!id_layer_cache)
> + id_layer_cache = kmem_cache_create("id_layer_cache",
> + sizeof(struct id_layer), 0, 0, 0, 0);
> +}
> +
> +void id2ptr_init(struct id *idp, int min_wrap)
> +{
> + init_id_cache();
> + idp->count = 1;
> + idp->last = 0;
> + idp->layers = 1;
> + idp->top = kmem_cache_alloc(id_layer_cache, GFP_KERNEL);
> + memset(idp->top, 0, sizeof(struct id_layer));
> + idp->top->bitmap = 0;
> + idp->min_wrap = min_wrap;
> +}
> +
> +__initcall(init_id_cache);
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/posix-timers.c linux.mytimers/kernel/posix-timers.c
> --- linux.orig/kernel/posix-timers.c Wed Dec 31 19:00:00 1969
> +++ linux.mytimers/kernel/posix-timers.c Wed Oct 23 01:56:45 2002
> @@ -0,0 +1,1109 @@
> +/*
> + * linux/kernel/posix_timers.c
> + *
> + *
> + * 2002-10-15 Posix Clocks & timers by George Anzinger
> + * Copyright (C) 2002 by MontaVista Software.
> + *
> + * 2002-10-18 changes by Jim Houston jim.houston@attbi.com
> + * Copyright (C) 2002 by Concurrent Computer Corp.
> + *
> + * - Add a separate queue for posix timers. Its a
> + * priority queue implemented as a sorted doubly
> + * linked list & a rbtree as an index into the list.
> + * - Use a slab cache to allocate the timer structures.
> + * - Allocate timer ids using my new id allocator.
> + * This avoids the immediate reuse of timer ids.
> + * - Uses seconds and nano-seconds rather than
> + * jiffies and sub_jiffies.
> + *
> + * This is an experimental change. I'm sending it out to
> + * the mailing list in the hope that it will stimulate
> + * discussion.
> + */
> +
> +/* These are all the functions necessary to implement
> + * POSIX clocks & timers
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/smp_lock.h>
> +#include <linux/interrupt.h>
> +#include <linux/slab.h>
> +#include <linux/time.h>
> +
> +#include <asm/uaccess.h>
> +#include <asm/semaphore.h>
> +#include <linux/list.h>
> +#include <linux/init.h>
> +#include <linux/nmi.h>
> +#include <linux/compiler.h>
> +#include <linux/id2ptr.h>
> +#include <linux/rbtree.h>
> +#include <linux/posix-timers.h>
> +
> +
> +#ifndef div_long_long_rem
> +#include <asm/div64.h>
> +
> +#define div_long_long_rem(dividend,divisor,remainder) ({ \
> + u64 result = dividend; \
> + *remainder = do_div(result,divisor); \
> + result; })
> +
> +#endif /* ifndef div_long_long_rem */
> +
> +
> +/*
> + * Lets keep our timers in a slab cache :-)
> + */
> +static kmem_cache_t *posix_timers_cache;
> +struct id posix_timers_id;
> +
> +/*
> + * This lock portects the timer queues it is held for the
> + * duration of the timer expiry process.
> + */
> +spinlock_t posix_timers_lock = SPIN_LOCK_UNLOCKED;
> +
> +/*
> + * Kluge until I can wire into the timer interrupt.
> + */
> +int poll_timer_running;
> +void run_posix_timers(unsigned long dummy);
> +static struct timer_list poll_posix_timers = {
> + .function = &run_posix_timers,
> +};
> +
> +struct k_clock clock_realtime = {
> + .pq = TIMER_PQ_INIT(clock_realtime.pq),
> + .res = NSEC_PER_SEC/HZ,
> +};
> +
> +struct k_clock clock_monotonic = {
> + .pq = TIMER_PQ_INIT(clock_monotonic.pq),
> + .res= NSEC_PER_SEC/HZ,
> + .clock_get = do_posix_clock_monotonic_gettime,
> + .clock_set = do_posix_clock_monotonic_settime
> +};
> +
> +/*
> + * Insert a timer into a priority queue. This is a sorted
> + * list of timers. A rbtree is used to index the list.
> + */
> +
> +static int timer_insert_nolock(struct timer_pq *pq, struct k_itimer *t)
> +{
> + struct rb_node ** p = &pq->rb_root.rb_node;
> + struct rb_node * parent = NULL;
> + struct k_itimer *cur;
> + struct list_head *prev;
> + prev = &pq->head;
> +
> + if (t->it_pq)
> + BUG();
> + t->it_pq = pq;
> + while (*p) {
> + parent = *p;
> + cur = rb_entry(parent, struct k_itimer , it_pq_node);
> +
> + /*
> + * We allow non unique entries. This works
> + * but there might be opportunity to do something
> + * clever.
> + */
> + if (t->it_v.it_value.tv_sec < cur->it_v.it_value.tv_sec ||
> + (t->it_v.it_value.tv_sec == cur->it_v.it_value.tv_sec &&
> + t->it_v.it_value.tv_nsec < cur->it_v.it_value.tv_nsec))
> + p = &(*p)->rb_left;
> + else {
> + prev = &cur->it_pq_list;
> + p = &(*p)->rb_right;
> + }
> + }
> + /* link into rbtree. */
> + rb_link_node(&t->it_pq_node, parent, p);
> + rb_insert_color(&t->it_pq_node, &pq->rb_root);
> + /* link it into the list */
> + list_add(&t->it_pq_list, prev);
> + /*
> + * We need to setup a timer interrupt if the new timer is
> + * at the head of the queue.
> + */
> + return(pq->head.next == &t->it_pq_list);
> +}
> +
> +static inline void timer_remove_nolock(struct k_itimer *t)
> +{
> + struct timer_pq *pq;
> +
> + if (!(pq = t->it_pq))
> + return;
> + rb_erase(&t->it_pq_node, &pq->rb_root);
> + list_del(&t->it_pq_list);
> + t->it_pq = 0;
> +}
> +
> +static void timer_remove(struct k_itimer *t)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&posix_timers_lock, flags);
> + timer_remove_nolock(t);
> + spin_unlock_irqrestore(&posix_timers_lock, flags);
> +}
> +
> +
> +static int timer_insert(struct timer_pq *pq, struct k_itimer *t)
> +{
> + unsigned long flags;
> + int rv;
> +
> + spin_lock_irqsave(&posix_timers_lock, flags);
> + rv = timer_insert_nolock(pq, t);
> + spin_unlock_irqrestore(&posix_timers_lock, flags);
> + if (!poll_timer_running) {
> + poll_timer_running = 1;
> + poll_posix_timers.expires = jiffies + 1;
> + add_timer(&poll_posix_timers);
> + }
> + return(rv);
> +}
> +
> +/*
> + * If we are late delivering a periodic timer we may
> + * have missed several expiries. We want to calculate the
> + * number we have missed both as the overrun count but also
> + * so that we can pick next expiry.
> + *
> + * You really need this if you schedule a high frequency timer
> + * and then make a big change to the current time.
> + */
> +
> +int handle_overrun(struct k_itimer *t, struct timespec dt)
> +{
> + int ovr;
> +#if 0
> + long long ldt, in;
> + long sec, nsec;
> +
> + in = (long long)t->it_v.it_interval.tv_sec*1000000000 +
> + t->it_v.it_interval.tv_nsec;
> + ldt = (long long)dt.tv_sec * 1000000000 + dt.tv_nsec;
> + ovr = ldt/in + 1;
> + ldt = (long long)t->it_v.it_interval.tv_nsec * ovr;
> + nsec = ldt % 1000000000;
> + sec = ldt / 1000000000;
> + sec += ovr * t->it_v.it_interval.tv_sec;
> + nsec += t->it_v.it_value.tv_nsec;
> + sec += t->it_v.it_value.tv_sec;
> + if (nsec > 1000000000) {
> + sec++;
> + nsec -= 1000000000;
> + }
> + t->it_v.it_value.tv_sec = sec;
> + t->it_v.it_value.tv_nsec = nsec;
> +#else
> + /* Temporary hack */
> + ovr = 0;
> + while (dt.tv_sec > t->it_v.it_interval.tv_sec ||
> + (dt.tv_sec == t->it_v.it_interval.tv_sec &&
> + dt.tv_nsec > t->it_v.it_interval.tv_nsec)) {
> + dt.tv_sec -= t->it_v.it_interval.tv_sec;
> + dt.tv_nsec -= t->it_v.it_interval.tv_nsec;
> + if (dt.tv_nsec < 0) {
> + dt.tv_sec--;
> + dt.tv_nsec += 1000000000;
> + }
> + t->it_v.it_value.tv_sec += t->it_v.it_interval.tv_sec;
> + t->it_v.it_value.tv_nsec += t->it_v.it_interval.tv_nsec;
> + if (t->it_v.it_value.tv_nsec >= 1000000000) {
> + t->it_v.it_value.tv_sec++;
> + t->it_v.it_value.tv_nsec -= 1000000000;
> + }
> + ovr++;
> + }
> +#endif
> + return(ovr);
> +}
> +
> +int sending_signal_failed;
> +
> +/*
> + * Yes I calculate an overrun but don't deliver it. I need to
> + * play with this code.
> + */
> +static void timer_notify_task(struct k_itimer *timr, int ovr)
> +{
> + struct siginfo info;
> + int ret;
> +
> + if (! (timr->it_sigev_notify & SIGEV_NONE)) {
> + memset(&info, 0, sizeof(info));
> + /* Send signal to the process that owns this timer. */
> + info.si_signo = timr->it_sigev_signo;
> + info.si_errno = 0;
> + info.si_code = SI_TIMER;
> + info.si_tid = timr->it_id;
> + info.si_value = timr->it_sigev_value;
> + info.si_overrun = timr->it_overrun_deferred;
> + ret = send_sig_info(info.si_signo, &info, timr->it_process);
> + switch (ret) {
> + case 0: /* all's well new signal queued */
> + timr->it_overrun_last = timr->it_overrun;
> + timr->it_overrun = timr->it_overrun_deferred;
> + break;
> + case 1: /* signal from this timer was already in the queue */
> + timr->it_overrun += timr->it_overrun_deferred + 1;
> + break;
> + default:
> + sending_signal_failed++;
> + break;
> + }
> + }
> +}
> +
> +void do_expiry(struct k_itimer *t, int ovr)
> +{
> + switch (t->it_type) {
> + case TIMER:
> + timer_notify_task(t, ovr);
> + return;
> + case NANOSLEEP:
> + wake_up_process(t->it_process);
> + return;
> + }
> +}
> +
> +/*
> + * Check if the timer at the head of the priority queue has
> + * expired and handle the expiry. Return time in nsec till
> + * the next expiry. We only really care about expiries
> + * before the next clock tick so we use a 32 bit int here.
> + */
> +
> +static int check_expiry(struct timer_pq *pq, struct timespec *tv)
> +{
> + struct k_itimer *t;
> + struct timespec dt;
> + int ovr;
> + long sec, nsec;
> + unsigned long flags;
> +
> + ovr = 1;
> + spin_lock_irqsave(&posix_timers_lock, flags);
> + while (!list_empty(&pq->head)) {
> + t = list_entry(pq->head.next, struct k_itimer, it_pq_list);
> + dt.tv_sec = tv->tv_sec - t->it_v.it_value.tv_sec;
> + dt.tv_nsec = tv->tv_nsec - t->it_v.it_value.tv_nsec;
> + if (dt.tv_sec < 0 || (dt.tv_sec == 0 && dt.tv_nsec < 0)) {
> + /*
> + * It has not expired yet. Return nano-seconds
> + * remaining if its less than a second.
> + */
> + if (dt.tv_sec < -1)
> + nsec = -1;
> + else
> + nsec = dt.tv_sec ? 1000000000-dt.tv_nsec :
> + -dt.tv_nsec;
> + spin_unlock_irqrestore(&posix_timers_lock, flags);
> + return(nsec);
> + }
> + /*
> + * Its expired. If this is a periodic timer we need to
> + * setup for the next expiry. We also check for overrun
> + * here. If the timer has already missed an expiry we want
> + * deliver the overrun information and get back on schedule.
> + */
> + if (dt.tv_nsec < 0) {
> + dt.tv_sec--;
> + dt.tv_nsec += 1000000000;
> + }
> + timer_remove_nolock(t);
> + if (t->it_v.it_interval.tv_sec || t->it_v.it_interval.tv_nsec) {
> + if (dt.tv_sec > t->it_v.it_interval.tv_sec ||
> + (dt.tv_sec == t->it_v.it_interval.tv_sec &&
> + dt.tv_nsec > t->it_v.it_interval.tv_nsec)) {
> + ovr = handle_overrun(t, dt);
> + } else {
> + nsec = t->it_v.it_value.tv_nsec +
> + t->it_v.it_interval.tv_nsec;
> + sec = t->it_v.it_value.tv_sec +
> + t->it_v.it_interval.tv_sec;
> + if (nsec > 1000000000) {
> + nsec -= 1000000000;
> + sec++;
> + }
> + t->it_v.it_value.tv_sec = sec;
> + t->it_v.it_value.tv_nsec = nsec;
> + }
> + /*
> + * It might make sense to leave the timer queue and
> + * avoid the remove/insert for timers which stay
> + * at the front of the queue.
> + */
> + timer_insert_nolock(pq, t);
> + }
> + do_expiry(t, ovr);
> + }
> + spin_unlock_irqrestore(&posix_timers_lock, flags);
> + return(-1);
> +}
> +
> +/*
> + * kluge? We should know the offset between clock_realtime and
> + * clock_monotonic so we don't need to get the time twice.
> + */
> +
> +void run_posix_timers(unsigned long dummy)
> +{
> + struct timespec now;
> + int ns, ret;
> +
> + ns = 0x7fffffff;
> + do_posix_clock_monotonic_gettime(&now);
> + ret = check_expiry(&clock_monotonic.pq, &now);
> + if (ret > 0 && ret < ns)
> + ns = ret;
> +
> + do_gettimeofday((struct timeval*)&now);
> + now.tv_nsec *= NSEC_PER_USEC;
> + ret = check_expiry(&clock_realtime.pq, &now);
> + if (ret > 0 && ret < ns)
> + ns = ret;
> + poll_posix_timers.expires = jiffies + 1;
> + add_timer(&poll_posix_timers);
> +}
> +
> +
> +extern rwlock_t xtime_lock;
> +
> +/*
> + * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
> + * to implement others. This structure defines the various
> + * clocks and allows the possibility of adding others. We
> + * provide an interface to add clocks to the table and expect
> + * the "arch" code to add at least one clock that is high
> + * resolution. Here we define the standard CLOCK_REALTIME as a
> + * 1/HZ resolution clock.
> +
> + * CPUTIME & THREAD_CPUTIME: We are not, at this time, definding these
> + * two clocks (and the other process related clocks (Std
> + * 1003.1d-1999). The way these should be supported, we think,
> + * is to use large negative numbers for the two clocks that are
> + * pinned to the executing process and to use -pid for clocks
> + * pinned to particular pids. Calls which supported these clock
> + * ids would split early in the function.
> +
> + * RESOLUTION: Clock resolution is used to round up timer and interval
> + * times, NOT to report clock times, which are reported with as
> + * much resolution as the system can muster. In some cases this
> + * resolution may depend on the underlaying clock hardware and
> + * may not be quantifiable until run time, and only then is the
> + * necessary code is written. The standard says we should say
> + * something about this issue in the documentation...
> +
> + * FUNCTIONS: The CLOCKs structure defines possible functions to handle
> + * various clock functions. For clocks that use the standard
> + * system timer code these entries should be NULL. This will
> + * allow dispatch without the overhead of indirect function
> + * calls. CLOCKS that depend on other sources (e.g. WWV or GPS)
> + * must supply functions here, even if the function just returns
> + * ENOSYS. The standard POSIX timer management code assumes the
> + * following: 1.) The k_itimer struct (sched.h) is used for the
> + * timer. 2.) The list, it_lock, it_clock, it_id and it_process
> + * fields are not modified by timer code.
> + *
> + * Permissions: It is assumed that the clock_settime() function defined
> + * for each clock will take care of permission checks. Some
> + * clocks may be set able by any user (i.e. local process
> + * clocks) others not. Currently the only set able clock we
> + * have is CLOCK_REALTIME and its high res counter part, both of
> + * which we beg off on and pass to do_sys_settimeofday().
> + */
> +
> +struct k_clock *posix_clocks[MAX_CLOCKS];
> +
> +#define if_clock_do(clock_fun, alt_fun,parms) (! clock_fun)? alt_fun parms :\
> + clock_fun parms
> +
> +#define p_timer_get( clock,a,b) if_clock_do((clock)->timer_get, \
> + do_timer_gettime, \
> + (a,b))
> +
> +#define p_nsleep( clock,a,b,c) if_clock_do((clock)->nsleep, \
> + do_nsleep, \
> + (a,b,c))
> +
> +#define p_timer_del( clock,a) if_clock_do((clock)->timer_del, \
> + do_timer_delete, \
> + (a))
> +
> +void register_posix_clock(int clock_id, struct k_clock * new_clock);
> +
> +static int do_posix_gettime(struct k_clock *clock, struct timespec *tp);
> +
> +
> +void register_posix_clock(int clock_id,struct k_clock * new_clock)
> +{
> + if ((unsigned)clock_id >= MAX_CLOCKS) {
> + printk("POSIX clock register failed for clock_id %d\n",clock_id);
> + return;
> + }
> + posix_clocks[clock_id] = new_clock;
> +}
> +
> +static __init int init_posix_timers(void)
> +{
> + posix_timers_cache = kmem_cache_create("posix_timers_cache",
> + sizeof(struct k_itimer), 0, 0, 0, 0);
> + id2ptr_init(&posix_timers_id, 1000);
> +
> + register_posix_clock(CLOCK_REALTIME,&clock_realtime);
> + register_posix_clock(CLOCK_MONOTONIC,&clock_monotonic);
> + return 0;
> +}
> +
> +__initcall(init_posix_timers);
> +
> +/*
> + * For some reason mips/mips64 define the SIGEV constants plus 128.
> + * Here we define a mask to get rid of the common bits. The
> + * optimizer should make this costless to all but mips.
> + */
> +#if (ARCH == mips) || (ARCH == mips64)
> +#define MIPS_SIGEV ~(SIGEV_NONE & \
> + SIGEV_SIGNAL & \
> + SIGEV_THREAD & \
> + SIGEV_THREAD_ID)
> +#else
> +#define MIPS_SIGEV (int)-1
> +#endif
> +
> +static struct task_struct * good_sigevent(sigevent_t *event)
> +{
> + struct task_struct * rtn = current;
> +
> + if (event->sigev_notify & SIGEV_THREAD_ID & MIPS_SIGEV ) {
> + if ( !(rtn = find_task_by_pid(event->sigev_notify_thread_id)) ||
> + rtn->tgid != current->tgid){
> + return NULL;
> + }
> + }
> + if (event->sigev_notify & SIGEV_SIGNAL & MIPS_SIGEV) {
> + if ((unsigned)(event->sigev_signo > SIGRTMAX))
> + return NULL;
> + }
> + if (event->sigev_notify & ~(SIGEV_SIGNAL | SIGEV_THREAD_ID )) {
> + return NULL;
> + }
> + return rtn;
> +}
> +
> +
> +
> +static struct k_itimer * alloc_posix_timer(void)
> +{
> + struct k_itimer *tmr;
> + tmr = kmem_cache_alloc(posix_timers_cache, GFP_KERNEL);
> + memset(tmr, 0, sizeof(struct k_itimer));
> + return(tmr);
> +}
> +
> +static void release_posix_timer(struct k_itimer *tmr)
> +{
> + if (tmr->it_id > 0)
> + id2ptr_remove(&posix_timers_id, tmr->it_id);
> + kmem_cache_free(posix_timers_cache, tmr);
> +}
> +
> +/* Create a POSIX.1b interval timer. */
> +
> +asmlinkage int
> +sys_timer_create(clockid_t which_clock, struct sigevent *timer_event_spec,
> + timer_t *created_timer_id)
> +{
> + int error = 0;
> + struct k_itimer *new_timer = NULL;
> + int new_timer_id;
> + struct task_struct * process = 0;
> + sigevent_t event;
> +
> + if ((unsigned)which_clock >= MAX_CLOCKS || !posix_clocks[which_clock])
> + return -EINVAL;
> +
> + new_timer = alloc_posix_timer();
> + if (new_timer == NULL) return -EAGAIN;
> +
> + new_timer_id = (timer_t)id2ptr_new(&posix_timers_id,
> + (void *)new_timer);
> + if (!new_timer_id) {
> + error = -EAGAIN;
> + goto out;
> + }
> + new_timer->it_id = new_timer_id;
> +
> + if (copy_to_user(created_timer_id, &new_timer_id,
> + sizeof(new_timer_id))) {
> + error = -EFAULT;
> + goto out;
> + }
> + spin_lock_init(&new_timer->it_lock);
> + if (timer_event_spec) {
> + if (copy_from_user(&event, timer_event_spec, sizeof(event))) {
> + error = -EFAULT;
> + goto out;
> + }
> + read_lock(&tasklist_lock);
> + if ((process = good_sigevent(&event))) {
> + /*
> + * We may be setting up this timer for another
> + * thread. It may be exitiing. To catch this
> + * case the we clear posix_timers.next in
> + * exit_itimers.
> + */
> + spin_lock(&process->alloc_lock);
> + if (process->posix_timers.next) {
> + list_add(&new_timer->it_task_list,
> + &process->posix_timers);
> + spin_unlock(&process->alloc_lock);
> + } else {
> + spin_unlock(&process->alloc_lock);
> + process = 0;
> + }
> + }
> + read_unlock(&tasklist_lock);
> + if (!process) {
> + error = -EINVAL;
> + goto out;
> + }
> + new_timer->it_sigev_notify = event.sigev_notify;
> + new_timer->it_sigev_signo = event.sigev_signo;
> + new_timer->it_sigev_value = event.sigev_value;
> + } else {
> + new_timer->it_sigev_notify = SIGEV_SIGNAL;
> + new_timer->it_sigev_signo = SIGALRM;
> + new_timer->it_sigev_value.sival_int = new_timer->it_id;
> + process = current;
> + spin_lock(&current->alloc_lock);
> + list_add(&new_timer->it_task_list, &current->posix_timers);
> + spin_unlock(&current->alloc_lock);
> + }
> + new_timer->it_clock = which_clock;
> + new_timer->it_overrun = 0;
> + new_timer->it_process = process;
> +
> + out:
> + if (error)
> + release_posix_timer(new_timer);
> + return error;
> +}
> +
> +
> +/*
> + * return timer owned by the process, used by exit and exec
> + */
> +void itimer_delete(struct k_itimer *timer)
> +{
> + if (sys_timer_delete(timer->it_id)){
> + BUG();
> + }
> +}
> +
> +/*
> + * This is call from both exec and exit to shutdown the
> + * timers.
> + */
> +
> +inline void exit_itimers(struct task_struct *tsk, int exit)
> +{
> + struct k_itimer *tmr;
> +
> + if (!tsk->posix_timers.next)
> + BUG();
> + if (tsk->nanosleep_tmr.it_pq)
> + timer_remove(&tsk->nanosleep_tmr);
> + spin_lock(&tsk->alloc_lock);
> + while (tsk->posix_timers.next != &tsk->posix_timers){
> + spin_unlock(&tsk->alloc_lock);
> + tmr = list_entry(tsk->posix_timers.next,struct k_itimer,
> + it_task_list);
> + itimer_delete(tmr);
> + spin_lock(&tsk->alloc_lock);
> + }
> + /*
> + * sys_timer_create has the option to create a timer
> + * for another thread. There is the risk that as the timer
> + * is being created that the thread that was supposed to handle
> + * the signal is exiting. We use the posix_timers.next field
> + * as a flag so we can close this race.
> +` */
> + if (exit)
> + tsk->posix_timers.next = 0;
> + spin_unlock(&tsk->alloc_lock);
> +}
> +
> +/* good_timespec
> + *
> + * This function checks the elements of a timespec structure.
> + *
> + * Arguments:
> + * ts : Pointer to the timespec structure to check
> + *
> + * Return value:
> + * If a NULL pointer was passed in, or the tv_nsec field was less than 0 or
> + * greater than NSEC_PER_SEC, or the tv_sec field was less than 0, this
> + * function returns 0. Otherwise it returns 1.
> + */
> +
> +static int good_timespec(const struct timespec *ts)
> +{
> + if ((ts == NULL) ||
> + (ts->tv_sec < 0) ||
> + ((unsigned)ts->tv_nsec >= NSEC_PER_SEC))
> + return 0;
> + return 1;
> +}
> +
> +static inline void unlock_timer(struct k_itimer *timr)
> +{
> + spin_unlock_irq(&timr->it_lock);
> +}
> +
> +static struct k_itimer* lock_timer( timer_t timer_id)
> +{
> + struct k_itimer *timr;
> +
> + timr = (struct k_itimer *)id2ptr_lookup(&posix_timers_id,
> + (int)timer_id);
> + if (timr)
> + spin_lock_irq(&timr->it_lock);
> + return(timr);
> +}
> +
> +/*
> + * Get the time remaining on a POSIX.1b interval timer.
> + * This function is ALWAYS called with spin_lock_irq on the timer, thus
> + * it must not mess with irq.
> + */
> +void inline do_timer_gettime(struct k_itimer *timr,
> + struct itimerspec *cur_setting)
> +{
> + struct timespec ts;
> +
> + do_posix_gettime(posix_clocks[timr->it_clock], &ts);
> + ts.tv_sec = timr->it_v.it_value.tv_sec - ts.tv_sec;
> + ts.tv_nsec = timr->it_v.it_value.tv_nsec - ts.tv_nsec;
> + if (ts.tv_nsec < 0) {
> + ts.tv_nsec += 1000000000;
> + ts.tv_sec--;
> + }
> + if (ts.tv_sec < 0)
> + ts.tv_sec = ts.tv_nsec = 0;
> + cur_setting->it_value = ts;
> + cur_setting->it_interval = timr->it_v.it_interval;
> +}
> +
> +/* Get the time remaining on a POSIX.1b interval timer. */
> +asmlinkage int sys_timer_gettime(timer_t timer_id, struct itimerspec *setting)
> +{
> + struct k_itimer *timr;
> + struct itimerspec cur_setting;
> +
> + timr = lock_timer(timer_id);
> + if (!timr) return -EINVAL;
> +
> + p_timer_get(posix_clocks[timr->it_clock],timr, &cur_setting);
> +
> + unlock_timer(timr);
> +
> + if (copy_to_user(setting, &cur_setting, sizeof(cur_setting)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +/*
> + * Get the number of overruns of a POSIX.1b interval timer
> + * This is a bit messy as we don't easily know where he is in the delivery
> + * of possible multiple signals. We are to give him the overrun on the
> + * last delivery. If we have another pending, we want to make sure we
> + * use the last and not the current. If there is not another pending
> + * then he is current and gets the current overrun. We search both the
> + * shared and local queue.
> + */
> +
> +asmlinkage int sys_timer_getoverrun(timer_t timer_id)
> +{
> + struct k_itimer *timr;
> + int overrun, i;
> + struct sigqueue *q;
> + struct sigpending *sig_queue;
> + struct task_struct * t;
> +
> + timr = lock_timer( timer_id);
> + if (!timr) return -EINVAL;
> +
> + t = timr->it_process;
> + overrun = timr->it_overrun;
> + spin_lock_irq(&t->sig->siglock);
> + for (sig_queue = &t->sig->shared_pending, i = 2; i;
> + sig_queue = &t->pending, i--){
> + for (q = sig_queue->head; q; q = q->next) {
> + if ((q->info.si_code == SI_TIMER) &&
> + (q->info.si_tid == timr->it_id)) {
> +
> + overrun = timr->it_overrun_last;
> + goto out;
> + }
> + }
> + }
> + out:
> + spin_unlock_irq(&t->sig->siglock);
> +
> + unlock_timer(timr);
> +
> + return overrun;
> +}
> +
> +/*
> + * If it is relative time, we need to add the current time to it to
> + * get the proper expiry time.
> + */
> +static int adjust_rel_time(struct k_clock *clock,struct timespec *tp)
> +{
> + struct timespec now;
> +
> +
> + do_posix_gettime(clock,&now);
> + tp->tv_sec += now.tv_sec;
> + tp->tv_nsec += now.tv_nsec;
> +
> + /*
> + * Normalize...
> + */
> + if (( tp->tv_nsec - NSEC_PER_SEC) >= 0){
> + tp->tv_nsec -= NSEC_PER_SEC;
> + tp->tv_sec++;
> + }
> + return 0;
> +}
> +
> +/* Set a POSIX.1b interval timer. */
> +/* timr->it_lock is taken. */
> +static inline int do_timer_settime(struct k_itimer *timr, int flags,
> + struct itimerspec *new_setting,
> + struct itimerspec *old_setting)
> +{
> + struct k_clock * clock = posix_clocks[timr->it_clock];
> +
> + timer_remove(timr);
> + if (old_setting) {
> + do_timer_gettime(timr, old_setting);
> + }
> +
> +
> + /* switch off the timer when it_value is zero */
> + if ((new_setting->it_value.tv_sec == 0) &&
> + (new_setting->it_value.tv_nsec == 0)) {
> + timr->it_v = *new_setting;
> + return 0;
> + }
> +
> + if (!(flags & TIMER_ABSTIME))
> + adjust_rel_time(clock, &new_setting->it_value);
> +
> + timr->it_v = *new_setting;
> + timr->it_overrun_deferred =
> + timr->it_overrun_last =
> + timr->it_overrun = 0;
> + timer_insert(&clock->pq, timr);
> + return 0;
> +}
> +
> +
> +
> +/* Set a POSIX.1b interval timer */
> +asmlinkage int sys_timer_settime(timer_t timer_id, int flags,
> + const struct itimerspec *new_setting,
> + struct itimerspec *old_setting)
> +{
> + struct k_itimer *timr;
> + struct itimerspec new_spec, old_spec;
> + int error = 0;
> + struct itimerspec *rtn = old_setting ? &old_spec : NULL;
> +
> +
> + if (new_setting == NULL) {
> + return -EINVAL;
> + }
> +
> + if (copy_from_user(&new_spec, new_setting, sizeof(new_spec))) {
> + return -EFAULT;
> + }
> +
> + if ((!good_timespec(&new_spec.it_interval)) ||
> + (!good_timespec(&new_spec.it_value))) {
> + return -EINVAL;
> + }
> +
> + timr = lock_timer( timer_id);
> + if (!timr)
> + return -EINVAL;
> +
> + if (! posix_clocks[timr->it_clock]->timer_set) {
> + error = do_timer_settime(timr, flags, &new_spec, rtn );
> + }else{
> + error = posix_clocks[timr->it_clock]->timer_set(timr,
> + flags,
> + &new_spec,
> + rtn );
> + }
> + unlock_timer(timr);
> +
> + if (old_setting && ! error) {
> + if (copy_to_user(old_setting, &old_spec, sizeof(old_spec))) {
> + error = -EFAULT;
> + }
> + }
> +
> + return error;
> +}
> +
> +static inline int do_timer_delete(struct k_itimer *timer)
> +{
> + timer_remove(timer);
> + return 0;
> +}
> +
> +/* Delete a POSIX.1b interval timer. */
> +asmlinkage int sys_timer_delete(timer_t timer_id)
> +{
> + struct k_itimer *timer;
> +
> + timer = lock_timer( timer_id);
> + if (!timer)
> + return -EINVAL;
> +
> + p_timer_del(posix_clocks[timer->it_clock],timer);
> +
> + spin_lock(&timer->it_process->alloc_lock);
> + list_del(&timer->it_task_list);
> + spin_unlock(&timer->it_process->alloc_lock);
> +
> + /*
> + * This keeps any tasks waiting on the spin lock from thinking
> + * they got something (see the lock code above).
> + */
> + timer->it_process = NULL;
> + unlock_timer(timer);
> + release_posix_timer(timer);
> + return 0;
> +}
> +/*
> + * And now for the "clock" calls
> + * These functions are called both from timer functions (with the timer
> + * spin_lock_irq() held and from clock calls with no locking. They must
> + * use the save flags versions of locks.
> + */
> +static int do_posix_gettime(struct k_clock *clock, struct timespec *tp)
> +{
> +
> + if (clock->clock_get){
> + return clock->clock_get(tp);
> + }
> +
> + do_gettimeofday((struct timeval*)tp);
> + tp->tv_nsec *= NSEC_PER_USEC;
> + return 0;
> +}
> +
> +/*
> + * We do ticks here to avoid the irq lock ( they take sooo long)
> + * Note also that the while loop assures that the sub_jiff_offset
> + * will be less than a jiffie, thus no need to normalize the result.
> + * Well, not really, if called with ints off :(
> + */
> +
> +int do_posix_clock_monotonic_gettime(struct timespec *tp)
> +{
> + long sub_sec;
> + u64 jiffies_64_f;
> +
> +#if (BITS_PER_LONG > 32)
> +
> + jiffies_64_f = jiffies_64;
> +
> +#elif defined(CONFIG_SMP)
> +
> + /* Tricks don't work here, must take the lock. Remember, called
> + * above from both timer and clock system calls => save flags.
> + */
> + {
> + unsigned long flags;
> + read_lock_irqsave(&xtime_lock, flags);
> + jiffies_64_f = jiffies_64;
> +
> +
> + read_unlock_irqrestore(&xtime_lock, flags);
> + }
> +#elif ! defined(CONFIG_SMP) && (BITS_PER_LONG < 64)
> + unsigned long jiffies_f;
> + do {
> + jiffies_f = jiffies;
> + barrier();
> + jiffies_64_f = jiffies_64;
> + } while (unlikely(jiffies_f != jiffies));
> +
> +
> +#endif
> + tp->tv_sec = div_long_long_rem(jiffies_64_f,HZ,&sub_sec);
> +
> + tp->tv_nsec = sub_sec * (NSEC_PER_SEC / HZ);
> + return 0;
> +}
> +
> +int do_posix_clock_monotonic_settime(struct timespec *tp)
> +{
> + return -EINVAL;
> +}
> +
> +asmlinkage int sys_clock_settime(clockid_t which_clock,const struct timespec *tp)
> +{
> + struct timespec new_tp;
> +
> + if ((unsigned)which_clock >= MAX_CLOCKS || !posix_clocks[which_clock])
> + return -EINVAL;
> + if (copy_from_user(&new_tp, tp, sizeof(*tp)))
> + return -EFAULT;
> + if ( posix_clocks[which_clock]->clock_set){
> + return posix_clocks[which_clock]->clock_set(&new_tp);
> + }
> + new_tp.tv_nsec /= NSEC_PER_USEC;
> + return do_sys_settimeofday((struct timeval*)&new_tp,NULL);
> +}
> +asmlinkage int sys_clock_gettime(clockid_t which_clock, struct timespec *tp)
> +{
> + struct timespec rtn_tp;
> + int error = 0;
> +
> + if ((unsigned)which_clock >= MAX_CLOCKS || !posix_clocks[which_clock])
> + return -EINVAL;
> +
> + error = do_posix_gettime(posix_clocks[which_clock],&rtn_tp);
> +
> + if ( ! error) {
> + if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp))) {
> + error = -EFAULT;
> + }
> + }
> + return error;
> +
> +}
> +asmlinkage int sys_clock_getres(clockid_t which_clock, struct timespec *tp)
> +{
> + struct timespec rtn_tp;
> +
> + if ((unsigned)which_clock >= MAX_CLOCKS || !posix_clocks[which_clock])
> + return -EINVAL;
> +
> + rtn_tp.tv_sec = 0;
> + rtn_tp.tv_nsec = posix_clocks[which_clock]->res;
> + if ( tp){
> + if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp))) {
> + return -EFAULT;
> + }
> + }
> + return 0;
> +
> +}
> +
> +#if 0
> +// This #if 0 is to keep the pretty printer/ formatter happy so the indents will
> +// correct below.
> +
> +// The NANOSLEEP_ENTRY macro is defined in asm/signal.h and
> +// is structured to allow code as well as entry definitions, so that when
> +// we get control back here the entry parameters will be available as expected.
> +// Some systems may find these paramerts in other ways than as entry parms,
> +// for example, struct pt_regs *regs is defined in i386 as the address of the
> +// first parameter, where as other archs pass it as one of the paramerters.
> +
> +asmlinkage long sys_clock_nanosleep(void)
> +{
> +#endif
> + CLOCK_NANOSLEEP_ENTRY( struct timespec ts;
> + struct k_itimer *t;
> + struct k_clock * clock;
> + int active;)
> +
> + //asmlinkage int sys_clock_nanosleep(clockid_t which_clock,
> + // int flags,
> + // const struct timespec *rqtp,
> + // struct timespec *rmtp)
> + //{
> +
> + if ((unsigned)which_clock >= MAX_CLOCKS || !posix_clocks[which_clock])
> + return -EINVAL;
> + /*
> + * See discussion below about waking up early.
> + */
> + clock = posix_clocks[which_clock];
> + t = &current->nanosleep_tmr;
> + if (t->it_pq)
> + timer_remove(t);
> +
> + if(copy_from_user(&t->it_v.it_value, rqtp, sizeof(struct timespec)))
> + return -EFAULT;
> +
> + if ((t->it_v.it_value.tv_nsec < 0) ||
> + (t->it_v.it_value.tv_nsec >= NSEC_PER_SEC) ||
> + (t->it_v.it_value.tv_sec < 0))
> + return -EINVAL;
> +
> + if (!(flags & TIMER_ABSTIME))
> + adjust_rel_time(clock, &t->it_v.it_value);
> + /*
> + * These fields don't need to be setup each time. This
> + * should be in the INIT_TASK() and forgoten.
> + */
> + t->it_v.it_interval.tv_sec = 0;
> + t->it_v.it_interval.tv_nsec = 0;
> + t->it_type = NANOSLEEP;
> + t->it_process = current;
> +
> + current->state = TASK_INTERRUPTIBLE;
> + timer_insert(&clock->pq, t);
> + schedule();
> + /*
> + * Were not supposed to leave early. The problem is
> + * being woken by signals that are not delivered to
> + * the user. Typically this means debug related
> + * signals.
> + *
> + * My plan is to leave the timer running and have a
> + * small hook in do_signal which will complete the
> + * nanosleep. For now we just return early in clear
> + * violation of the Posix spec.
> + */
> + active = (t->it_pq != 0);
> + if (!(flags & TIMER_ABSTIME) && active && rmtp ) {
> + do_posix_gettime(clock, &ts);
> + ts.tv_sec = t->it_v.it_value.tv_sec - ts.tv_sec;
> + ts.tv_nsec = t->it_v.it_value.tv_nsec - ts.tv_nsec;
> + if (ts.tv_nsec < 0) {
> + ts.tv_nsec += 1000000000;
> + ts.tv_sec--;
> + }
> + if (ts.tv_sec < 0)
> + ts.tv_sec = ts.tv_nsec = 0;
> + if (copy_to_user(rmtp, &ts, sizeof(struct timespec)))
> + return -EFAULT;
> + }
> + if (active)
> + return -EINTR;
> + return 0;
> +}
> +
> +void clock_was_set(void)
> +{
> +}
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/signal.c linux.mytimers/kernel/signal.c
> --- linux.orig/kernel/signal.c Wed Oct 23 00:54:30 2002
> +++ linux.mytimers/kernel/signal.c Wed Oct 23 01:17:51 2002
> @@ -424,8 +424,6 @@
> if (!collect_signal(sig, pending, info))
> sig = 0;
>
> - /* XXX: Once POSIX.1b timers are in, if si_code == SI_TIMER,
> - we need to xchg out the timer overrun values. */
> }
> recalc_sigpending();
>
> @@ -692,6 +690,7 @@
> specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t, int shared)
> {
> int ret;
> + struct sigpending *sig_queue;
>
> if (!irqs_disabled())
> BUG();
> @@ -725,20 +724,43 @@
> if (ignored_signal(sig, t))
> goto out;
>
> + sig_queue = shared ? &t->sig->shared_pending : &t->pending;
> +
> #define LEGACY_QUEUE(sigptr, sig) \
> (((sig) < SIGRTMIN) && sigismember(&(sigptr)->signal, (sig)))
> -
> + /*
> + * Support queueing exactly one non-rt signal, so that we
> + * can get more detailed information about the cause of
> + * the signal.
> + */
> + if (LEGACY_QUEUE(sig_queue, sig))
> + goto out;
> + /*
> + * In case of a POSIX timer generated signal you must check
> + * if a signal from this timer is already in the queue.
> + * If that is true, the overrun count will be increased in
> + * itimer.c:posix_timer_fn().
> + */
> +
> + if (((unsigned long)info > 1) && (info->si_code == SI_TIMER)) {
> + struct sigqueue *q;
> + for (q = sig_queue->head; q; q = q->next) {
> + if ((q->info.si_code == SI_TIMER) &&
> + (q->info.si_tid == info->si_tid)) {
> + q->info.si_overrun += info->si_overrun + 1;
> + /*
> + * this special ret value (1) is recognized
> + * only by posix_timer_fn() in itimer.c
> + */
> + ret = 1;
> + goto out;
> + }
> + }
> + }
> if (!shared) {
> - /* Support queueing exactly one non-rt signal, so that we
> - can get more detailed information about the cause of
> - the signal. */
> - if (LEGACY_QUEUE(&t->pending, sig))
> - goto out;
>
> ret = deliver_signal(sig, info, t);
> } else {
> - if (LEGACY_QUEUE(&t->sig->shared_pending, sig))
> - goto out;
> ret = send_signal(sig, info, &t->sig->shared_pending);
> }
> out:
> @@ -1418,8 +1440,9 @@
> err |= __put_user(from->si_uid, &to->si_uid);
> break;
> case __SI_TIMER:
> - err |= __put_user(from->si_timer1, &to->si_timer1);
> - err |= __put_user(from->si_timer2, &to->si_timer2);
> + err |= __put_user(from->si_tid, &to->si_tid);
> + err |= __put_user(from->si_overrun, &to->si_overrun);
> + err |= __put_user(from->si_ptr, &to->si_ptr);
> break;
> case __SI_POLL:
> err |= __put_user(from->si_band, &to->si_band);
> diff -X /usr1/jhouston/dontdiff -urN linux.orig/kernel/timer.c linux.mytimers/kernel/timer.c
> --- linux.orig/kernel/timer.c Wed Oct 23 00:54:21 2002
> +++ linux.mytimers/kernel/timer.c Wed Oct 23 01:17:51 2002
> @@ -47,12 +47,11 @@
> struct list_head vec[TVR_SIZE];
> } tvec_root_t;
>
> -typedef struct timer_list timer_t;
>
> struct tvec_t_base_s {
> spinlock_t lock;
> unsigned long timer_jiffies;
> - timer_t *running_timer;
> + struct timer_list *running_timer;
> tvec_root_t tv1;
> tvec_t tv2;
> tvec_t tv3;
> @@ -67,7 +66,7 @@
> /* Fake initialization needed to avoid compiler breakage */
> static DEFINE_PER_CPU(struct tasklet_struct, timer_tasklet) = { NULL };
>
> -static inline void internal_add_timer(tvec_base_t *base, timer_t *timer)
> +static inline void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
> {
> unsigned long expires = timer->expires;
> unsigned long idx = expires - base->timer_jiffies;
> @@ -119,7 +118,7 @@
> * Timers with an ->expired field in the past will be executed in the next
> * timer tick. It's illegal to add an already pending timer.
> */
> -void add_timer(timer_t *timer)
> +void add_timer(struct timer_list *timer)
> {
> int cpu = get_cpu();
> tvec_base_t *base = tvec_bases + cpu;
> @@ -153,7 +152,7 @@
> * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
> * active timer returns 1.)
> */
> -int mod_timer(timer_t *timer, unsigned long expires)
> +int mod_timer(struct timer_list *timer, unsigned long expires)
> {
> tvec_base_t *old_base, *new_base;
> unsigned long flags;
> @@ -226,7 +225,7 @@
> * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
> * active timer returns 1.)
> */
> -int del_timer(timer_t *timer)
> +int del_timer(struct timer_list *timer)
> {
> unsigned long flags;
> tvec_base_t *base;
> @@ -263,7 +262,7 @@
> *
> * The function returns whether it has deactivated a pending timer or not.
> */
> -int del_timer_sync(timer_t *timer)
> +int del_timer_sync(struct timer_list *timer)
> {
> tvec_base_t *base = tvec_bases;
> int i, ret = 0;
> @@ -302,9 +301,9 @@
> * detach them individually, just clear the list afterwards.
> */
> while (curr != head) {
> - timer_t *tmp;
> + struct timer_list *tmp;
>
> - tmp = list_entry(curr, timer_t, entry);
> + tmp = list_entry(curr, struct timer_list, entry);
> if (tmp->base != base)
> BUG();
> next = curr->next;
> @@ -343,9 +342,9 @@
> if (curr != head) {
> void (*fn)(unsigned long);
> unsigned long data;
> - timer_t *timer;
> + struct timer_list *timer;
>
> - timer = list_entry(curr, timer_t, entry);
> + timer = list_entry(curr, struct timer_list, entry);
> fn = timer->function;
> data = timer->data;
>
> @@ -448,6 +447,7 @@
> if (xtime.tv_sec % 86400 == 0) {
> xtime.tv_sec--;
> time_state = TIME_OOP;
> + clock_was_set();
> printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n");
> }
> break;
> @@ -456,6 +456,7 @@
> if ((xtime.tv_sec + 1) % 86400 == 0) {
> xtime.tv_sec++;
> time_state = TIME_WAIT;
> + clock_was_set();
> printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n");
> }
> break;
> @@ -912,7 +913,7 @@
> */
> signed long schedule_timeout(signed long timeout)
> {
> - timer_t timer;
> + struct timer_list timer;
> unsigned long expire;
>
> switch (timeout)
> @@ -968,10 +969,32 @@
> return current->pid;
> }
>
> -asmlinkage long sys_nanosleep(struct timespec *rqtp, struct timespec *rmtp)
> +#if 0
> +// This #if 0 is to keep the pretty printer/ formatter happy so the indents will
> +// correct below.
> +// The NANOSLEEP_ENTRY macro is defined in asm/signal.h and
> +// is structured to allow code as well as entry definitions, so that when
> +// we get control back here the entry parameters will be available as expected.
> +// Some systems may find these paramerts in other ways than as entry parms,
> +// for example, struct pt_regs *regs is defined in i386 as the address of the
> +// first parameter, where as other archs pass it as one of the paramerters.
> +asmlinkage long sys_nanosleep(void)
> {
> - struct timespec t;
> - unsigned long expire;
> +#endif
> + NANOSLEEP_ENTRY( struct timespec t;
> + unsigned long expire;)
> +
> +#ifndef FOLD_NANO_SLEEP_INTO_CLOCK_NANO_SLEEP
> + // The following code expects rqtp, rmtp to be available
> + // as a result of the above macro. Also any regs needed
> + // for the _do_signal() macro shoule be set up here.
> +
> + //asmlinkage long sys_nanosleep(struct timespec *rqtp,
> + // struct timespec *rmtp)
> + // {
> + // struct timespec t;
> + // unsigned long expire;
> +
>
> if(copy_from_user(&t, rqtp, sizeof(struct timespec)))
> return -EFAULT;
> @@ -994,6 +1017,7 @@
> }
> return 0;
> }
> +#endif // ! FOLD_NANO_SLEEP_INTO_CLOCK_NANO_SLEEP
>
> /*
> * sys_sysinfo - fill in sysinfo struct
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

--
George Anzinger george@mvista.com
High-res-timers:
http://sourceforge.net/projects/high-res-timers/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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