Re: Posix compliant cpu clocks V7 [2/2]: Glibc patch
From: Christoph Lameter
Date: Thu Oct 07 2004 - 00:06:36 EST
Posix compliant CLOCK_THREAD_CPUTIME_ID and CLOCK_THREAD_CPUTIME_ID
The following patch makes glibc not provide the above clocks. Glibc will
either return an error or use the kernel interface.
This also defines all the posix clock routines in such a way that these
function work as documented by posix. It allows the specification of pids
when invoking clock_getcpuclockid() and pthread_getcpuclockid to obtain
the process or task clock of any process in the system.
Patch is cleaned up so that is does not move sections of code around.
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>
Index: libc/nptl/sysdeps/pthread/pthread_getcpuclockid.c
===================================================================
--- libc.orig/nptl/sysdeps/pthread/pthread_getcpuclockid.c 2003-06-24 16:53:20.000000000 -0700
+++ libc/nptl/sysdeps/pthread/pthread_getcpuclockid.c 2004-10-06 21:13:00.382271104 -0700
@@ -20,7 +20,7 @@
#include <pthreadP.h>
#include <sys/time.h>
#include <tls.h>
-
+#include <linux/threads.h>
int
pthread_getcpuclockid (threadid, clockid)
@@ -35,19 +35,8 @@
return ESRCH;
#ifdef CLOCK_THREAD_CPUTIME_ID
- /* We need to store the thread ID in the CLOCKID variable together
- with a number identifying the clock. We reserve the low 3 bits
- for the clock ID and the rest for the thread ID. This is
- problematic if the thread ID is too large. But 29 bits should be
- fine.
-
- If some day more clock IDs are needed the ID part can be
- enlarged. The IDs are entirely internal. */
- if (pd->tid >= 1 << (8 * sizeof (*clockid) - CLOCK_IDFIELD_SIZE))
- return ERANGE;
-
/* Store the number. */
- *clockid = CLOCK_THREAD_CPUTIME_ID | (pd->tid << CLOCK_IDFIELD_SIZE);
+ *clockid = - (pd->tid + PID_MAX_LIMIT);
return 0;
#else
Index: libc/sysdeps/unix/sysv/linux/clock_getres.c
===================================================================
--- libc.orig/sysdeps/unix/sysv/linux/clock_getres.c 2004-09-28 15:22:02.351950224 -0700
+++ libc/sysdeps/unix/sysv/linux/clock_getres.c 2004-10-06 21:19:57.842807456 -0700
@@ -20,24 +20,20 @@
#include "kernel-features.h"
-
#ifdef __ASSUME_POSIX_TIMERS
-/* This means the REALTIME and MONOTONIC clock are definitely
- supported in the kernel. */
-# define SYSDEP_GETRES \
- case CLOCK_REALTIME: \
- case CLOCK_MONOTONIC: \
- retval = INLINE_SYSCALL (clock_getres, 2, clock_id, res); \
- break
+/* we have to rely on the kernel */
+#define SYSDEP_DEFAULT_GETRES { \
+ INTERNAL_SYSCALL_DECL(err); \
+ retval = INTERNAL_SYSCALL(clock_getres, err, 2, clock_id, res); \
+ }
+
#elif defined __NR_clock_getres
/* Is the syscall known to exist? */
extern int __libc_missing_posix_timers attribute_hidden;
/* The REALTIME and MONOTONIC clock might be available. Try the
syscall first. */
-# define SYSDEP_GETRES \
- case CLOCK_REALTIME: \
- case CLOCK_MONOTONIC: \
+# define SYSDEP_DEFAULT_GETRES \
{ \
int e = EINVAL; \
\
@@ -65,7 +61,7 @@
else \
__set_errno (e); \
} \
- break
+
#endif
#ifdef __NR_clock_getres
Index: libc/sysdeps/unix/clock_gettime.c
===================================================================
--- libc.orig/sysdeps/unix/clock_gettime.c 2004-09-28 15:22:02.192974392 -0700
+++ libc/sysdeps/unix/clock_gettime.c 2004-10-06 15:34:17.994743608 -0700
@@ -23,21 +23,6 @@
#include <libc-internal.h>
#include <ldsodefs.h>
-
-#if HP_TIMING_AVAIL
-/* Clock frequency of the processor. We make it a 64-bit variable
- because some jokers are already playing with processors with more
- than 4GHz. */
-static hp_timing_t freq;
-
-
-/* This function is defined in the thread library. */
-extern int __pthread_clock_gettime (clockid_t clock_id, hp_timing_t freq,
- struct timespec *tp)
- __attribute__ ((__weak__));
-#endif
-
-
/* Get current value of CLOCK and store it in TP. */
int
clock_gettime (clockid_t clock_id, struct timespec *tp)
@@ -66,58 +51,14 @@
#endif
default:
-#if HP_TIMING_AVAIL
- if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
- != CLOCK_THREAD_CPUTIME_ID)
-#endif
+#ifdef SYSDEP_DEFAULT_GETTIME
+ SYSDEP_DEFAULT_GETTIME;
+#else
{
__set_errno (EINVAL);
break;
}
-
-#if HP_TIMING_AVAIL
- /* FALLTHROUGH. */
- case CLOCK_PROCESS_CPUTIME_ID:
- {
- hp_timing_t tsc;
-
- if (__builtin_expect (freq == 0, 0))
- {
- /* This can only happen if we haven't initialized the `freq'
- variable yet. Do this now. We don't have to protect this
- code against multiple execution since all of them should
- lead to the same result. */
- freq = __get_clockfreq ();
- if (__builtin_expect (freq == 0, 0))
- /* Something went wrong. */
- break;
- }
-
- if (clock_id != CLOCK_PROCESS_CPUTIME_ID
- && __pthread_clock_gettime != NULL)
- {
- retval = __pthread_clock_gettime (clock_id, freq, tp);
- break;
- }
-
- /* Get the current counter. */
- HP_TIMING_NOW (tsc);
-
- /* Compute the offset since the start time of the process. */
- tsc -= GL(dl_cpuclock_offset);
-
- /* Compute the seconds. */
- tp->tv_sec = tsc / freq;
-
- /* And the nanoseconds. This computation should be stable until
- we get machines with about 16GHz frequency. */
- tp->tv_nsec = ((tsc % freq) * UINT64_C (1000000000)) / freq;
-
- retval = 0;
- }
- break;
#endif
}
-
return retval;
}
Index: libc/sysdeps/unix/sysv/linux/ia64/clock_getcpuclockid.c
===================================================================
--- libc.orig/sysdeps/unix/sysv/linux/ia64/clock_getcpuclockid.c 2004-09-28 15:22:02.595913136 -0700
+++ /dev/null1970-01-01 00:00:00.000000000 +0000
@@ -1,65 +0,0 @@
-/* Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
-
-#include <errno.h>
-#include <time.h>
-#include <unistd.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <fcntl.h>
-
-
-int
-clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
-{
- /* We don't allow any process ID but our own. */
- if (pid != 0 && pid != getpid ())
- return EPERM;
-
- static int itc_usable;
- int retval = ENOENT;
-
- if (__builtin_expect (itc_usable == 0, 0))
- {
- int newval = 1;
- int fd = open ("/proc/sal/itc_drift", O_RDONLY);
- if (__builtin_expect (fd != -1, 1))
- {
- char buf[16];
- /* We expect the file to contain a single digit followed by
- a newline. If the format changes we better not rely on
- the file content. */
- if (read (fd, buf, sizeof buf) != 2 || buf[0] != '0'
- || buf[1] != '\n')
- newval = -1;
-
- close (fd);
- }
-
- itc_usable = newval;
- }
-
- if (itc_usable > 0)
- {
- /* Store the number. */
- *clock_id = CLOCK_PROCESS_CPUTIME_ID;
- retval = 0;
- }
-
- return retval;
-}
Index: libc/sysdeps/unix/sysv/linux/clock_settime.c
===================================================================
--- libc.orig/sysdeps/unix/sysv/linux/clock_settime.c 2004-10-01 10:27:15.007445832 -0700
+++ libc/sysdeps/unix/sysv/linux/clock_settime.c 2004-10-06 21:22:01.041078472 -0700
@@ -20,21 +20,18 @@
#include "kernel-features.h"
-
#ifdef __ASSUME_POSIX_TIMERS
-/* This means the REALTIME clock is definitely supported in the
- kernel. */
-# define SYSDEP_SETTIME \
- case CLOCK_REALTIME: \
- retval = INLINE_SYSCALL (clock_settime, 2, clock_id, tp); \
- break
+#define SYSDEP_DEFAULT_SETTIME { \
+ INTERNAL_SYSCALL_DECL(err); \
+ retval = INTERNAL_SYSCALL(clock_settime, err, 2, clock_id, tp); \
+ }
+
#elif defined __NR_clock_settime
/* Is the syscall known to exist? */
extern int __libc_missing_posix_timers attribute_hidden;
/* The REALTIME clock might be available. Try the syscall first. */
-# define SYSDEP_SETTIME \
- case CLOCK_REALTIME: \
+# define SYSDEP_DEFAULT_SETTIME \
{ \
int e = EINVAL; \
\
@@ -64,8 +61,7 @@
__set_errno (e); \
retval = -1; \
} \
- } \
- break
+ }
#endif
#ifdef __NR_clock_settime
Index: libc/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ libc/sysdeps/unix/sysv/linux/clock_getcpuclockid.c 2004-10-06 21:33:48.687499864 -0700
@@ -0,0 +1,44 @@
+
+/* Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include <time.h>
+#include <unistd.h>
+
+int
+clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
+{
+ if (pid != 0 && pid != getpid ())
+#ifdef __ASSUME_POSIX_TIMERS
+ return -pid;
+#else
+/* We don't allow any process ID but our own. */
+ return EPERM;
+#endif
+
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+ /* Store the number. */
+ *clock_id = CLOCK_PROCESS_CPUTIME_ID;
+
+ return 0;
+#else
+ /* We don't have a timer for that. */
+ return ENOENT;
+#endif
+}
Index: libc/sysdeps/posix/clock_getres.c
===================================================================
--- libc.orig/sysdeps/posix/clock_getres.c 2004-09-28 15:22:02.032998712 -0700
+++ libc/sysdeps/posix/clock_getres.c 2004-10-06 14:48:30.854372424 -0700
@@ -23,13 +23,6 @@
#include <sys/param.h>
#include <libc-internal.h>
-
-#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
-/* Clock frequency of the processor. */
-static long int nsec;
-#endif
-
-
/* Get resolution of clock. */
int
clock_getres (clockid_t clock_id, struct timespec *res)
@@ -65,44 +58,15 @@
#endif /* handled REALTIME */
default:
-#if HP_TIMING_AVAIL
- if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
- != CLOCK_THREAD_CPUTIME_ID)
-#endif
- {
+#ifdef SYSDEP_DEFAULT_GETRES
+ SYSDEP_DEFAULT_GETRES;
+#else
+ {
__set_errno (EINVAL);
break;
}
-
-#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
- /* FALLTHROUGH. */
- case CLOCK_PROCESS_CPUTIME_ID:
- {
- if (__builtin_expect (nsec == 0, 0))
- {
- hp_timing_t freq;
-
- /* This can only happen if we haven't initialized the `freq'
- variable yet. Do this now. We don't have to protect this
- code against multiple execution since all of them should
- lead to the same result. */
- freq = __get_clockfreq ();
- if (__builtin_expect (freq == 0, 0))
- /* Something went wrong. */
- break;
-
- nsec = MAX (UINT64_C (1000000000) / freq, 1);
- }
-
- /* File in the values. The seconds are always zero (unless we
- have a 1Hz machine). */
- res->tv_sec = 0;
- res->tv_nsec = nsec;
-
- retval = 0;
- }
- break;
#endif
+
}
return retval;
Index: libc/sysdeps/unix/clock_settime.c
===================================================================
--- libc.orig/sysdeps/unix/clock_settime.c 2004-10-01 10:26:04.247203024 -0700
+++ libc/sysdeps/unix/clock_settime.c 2004-10-06 15:56:49.504282928 -0700
@@ -22,20 +22,6 @@
#include <libc-internal.h>
#include <ldsodefs.h>
-
-#if HP_TIMING_AVAIL
-/* Clock frequency of the processor. We make it a 64-bit variable
- because some jokers are already playing with processors with more
- than 4GHz. */
-static hp_timing_t freq;
-
-
-/* This function is defined in the thread library. */
-extern void __pthread_clock_settime (clockid_t clock_id, hp_timing_t offset)
- __attribute__ ((__weak__));
-#endif
-
-
/* Set CLOCK to value TP. */
int
clock_settime (clockid_t clock_id, const struct timespec *tp)
@@ -70,56 +56,16 @@
#endif
default:
-#if HP_TIMING_AVAIL
- if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
- != CLOCK_THREAD_CPUTIME_ID)
-#endif
+#ifdef SYSDEP_DEFAULT_SETTIME
+ SYSDEP_DEFAULT_SETTIME;
+#else
{
__set_errno (EINVAL);
retval = -1;
break;
}
-#if HP_TIMING_AVAIL
- /* FALLTHROUGH. */
- case CLOCK_PROCESS_CPUTIME_ID:
- {
- hp_timing_t tsc;
- hp_timing_t usertime;
-
- /* First thing is to get the current time. */
- HP_TIMING_NOW (tsc);
-
- if (__builtin_expect (freq == 0, 0))
- {
- /* This can only happen if we haven't initialized the `freq'
- variable yet. Do this now. We don't have to protect this
- code against multiple execution since all of them should
- lead to the same result. */
- freq = __get_clockfreq ();
- if (__builtin_expect (freq == 0, 0))
- {
- /* Something went wrong. */
- retval = -1;
- break;
- }
- }
-
- /* Convert the user-provided time into CPU ticks. */
- usertime = tp->tv_sec * freq + (tp->tv_nsec * freq) / 1000000000ull;
-
- /* Determine the offset and use it as the new base value. */
- if (clock_id == CLOCK_PROCESS_CPUTIME_ID
- || __pthread_clock_settime == NULL)
- GL(dl_cpuclock_offset) = tsc - usertime;
- else
- __pthread_clock_settime (clock_id, tsc - usertime);
-
- retval = 0;
- }
- break;
#endif
}
-
return retval;
}
Index: libc/sysdeps/unix/sysv/linux/kernel-features.h
===================================================================
--- libc.orig/sysdeps/unix/sysv/linux/kernel-features.h 2004-09-23 16:40:16.491315016 -0700
+++ libc/sysdeps/unix/sysv/linux/kernel-features.h 2004-10-06 12:03:27.941843960 -0700
@@ -419,3 +419,11 @@
#if __LINUX_KERNEL_VERSION >= 0x020609 && defined __alpha__
#define __ASSUME_IEEE_RAISE_EXCEPTION 1
#endif
+
+/* Starting with version 2.6.9, CLOCK_PROCESS/THREAD_CPUTIME_ID are supported
+ * with clock_gettime and also negative clockids to access other processes clocks
+ */
+
+#if __LINUX_KERNEL_VERSION >= 0x020609
+#define __ASSUME_POSIX_IMPROVED 1
+#endif
Index: libc/linuxthreads/sysdeps/pthread/getcpuclockid.c
===================================================================
--- libc.orig/linuxthreads/sysdeps/pthread/getcpuclockid.c 2004-07-12 09:16:56.800919000 -0700
+++ libc/linuxthreads/sysdeps/pthread/getcpuclockid.c 2004-10-06 12:40:44.548828016 -0700
@@ -21,25 +21,14 @@
#include <sys/time.h>
#include <time.h>
#include <internals.h>
+#include <linux/threads.h>
int
pthread_getcpuclockid (pthread_t thread_id, clockid_t *clock_id)
{
#ifdef CLOCK_THREAD_CPUTIME_ID
- /* We need to store the thread ID in the CLOCKID variable together
- with a number identifying the clock. We reserve the low 3 bits
- for the clock ID and the rest for the thread ID. This is
- problematic if the thread ID is too large. But 29 bits should be
- fine.
-
- If some day more clock IDs are needed the ID part can be
- enlarged. The IDs are entirely internal. */
- if (2 * PTHREAD_THREADS_MAX
- >= 1 << (8 * sizeof (*clock_id) - CLOCK_IDFIELD_SIZE))
- return ERANGE;
-
/* Store the number. */
- *clock_id = CLOCK_THREAD_CPUTIME_ID | (thread_id << CLOCK_IDFIELD_SIZE);
+ *clock_id = - (thread_id + PID_MAX_LIMIT);
return 0;
#else
Index: libc/sysdeps/unix/sysv/linux/clock_gettime.c
===================================================================
--- libc.orig/sysdeps/unix/sysv/linux/clock_gettime.c 2004-09-28 15:22:02.359949008 -0700
+++ libc/sysdeps/unix/sysv/linux/clock_gettime.c 2004-10-06 21:21:03.551818168 -0700
@@ -20,24 +20,19 @@
#include "kernel-features.h"
-
#ifdef __ASSUME_POSIX_TIMERS
-/* This means the REALTIME and MONOTONIC clock are definitely
- supported in the kernel. */
-# define SYSDEP_GETTIME \
- case CLOCK_REALTIME: \
- case CLOCK_MONOTONIC: \
- retval = INLINE_SYSCALL (clock_gettime, 2, clock_id, tp); \
- break
+#define SYSDEP_DEFAULT_GETTIME { \
+ INTERNAL_SYSCALL_DECL(err); \
+ retval = INTERNAL_SYSCALL(clock_gettime, err, 2, clock_id, tp); \
+ }
+
#elif defined __NR_clock_gettime
/* Is the syscall known to exist? */
int __libc_missing_posix_timers attribute_hidden;
/* The REALTIME and MONOTONIC clock might be available. Try the
syscall first. */
-# define SYSDEP_GETTIME \
- case CLOCK_REALTIME: \
- case CLOCK_MONOTONIC: \
+# define SYSDEP_DEFAULT_GETTIME \
{ \
int e = EINVAL; \
\
@@ -64,8 +59,7 @@
HANDLE_REALTIME; \
else \
__set_errno (e); \
- } \
- break
+ }
#endif
#ifdef __NR_clock_gettime
@@ -74,3 +68,4 @@
#endif
#include <sysdeps/unix/clock_gettime.c>
+
-
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