lkml.org 
[lkml]   [2003]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectLinux Kernel Precise Accounting (2.4.20)
Hi everybody,

we have developed a patch for a more precise CPU usage accounting.

The accounting in the standard kernel via the "cpu*" lines from /proc/stat
can produce misleading data for programs that give up the rest of their
timeslice, e.g. via usleep.

Our patch is based on the precise accounting patch for 2.2.14 and 2.4.0 by
Jan Astalos
(http://www.beowulf.org/pipermail/beowulf/2000-February/008415.html) and
uses the CPU time-stamp-counter on x86 CPUs for a clock-tick granularity.
We have enhanced the original patch for more current kernels (2.4.20 and
2.4.18 on our website (see below)), SMP capability, accounting of
interrupts and Soft-IRQs, and global as well as process-wise accounting.

With the patch the context switch latency increases by 10% (from 0.89
usec. to 0.97 usec. for 0k process size) as measured with lmbench.

The patch for 2.4.20 and 2.4.18 can be found at:
http://www.ti.uni-hd.de/HLT/documentation/software-and-documentation.html#kernel

The version for 2.4.20 is attached to this mail.

Please CC all comments to timm.steinbeck AT kip.uni-heidelberg.de and
arne.wiebalck AT kip.uni-heidelberg.de, as we are not subscribed to the
LKML.

Best regards
Arne & Timm

************************************************************************
Timm M. Steinbeck Kirchhoff Institute for Physics
Arne Wiebalck Technical Computer Science
INF 227, Room 3.315
D-69120 Heidelberg

e-mail: timm.steinbeck AT kip.uni-heidelberg.de Tel.: (+49) 6221/54-9816
web : http://www.kip.uni-heidelberg.de Fax.: (+49) 6221/54-9809
************************************************************************


-----------------------------8<------------------------------------

diff -ur linux-2.4.20/Makefile linux-2.4.20-pa/Makefile
--- linux-2.4.20/Makefile Fri Nov 29 00:53:16 2002
+++ linux-2.4.20-pa/Makefile Tue Feb 4 10:12:45 2003
@@ -1,7 +1,7 @@
VERSION = 2
PATCHLEVEL = 4
SUBLEVEL = 20
-EXTRAVERSION =
+EXTRAVERSION = -precacct

KERNELRELEASE=$(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)

diff -ur linux-2.4.20/arch/i386/config.in linux-2.4.20-pa/arch/i386/config.in
--- linux-2.4.20/arch/i386/config.in Fri Nov 29 00:53:09 2002
+++ linux-2.4.20-pa/arch/i386/config.in Tue Feb 4 10:11:58 2003
@@ -285,6 +285,9 @@

bool 'System V IPC' CONFIG_SYSVIPC
bool 'BSD Process Accounting' CONFIG_BSD_PROCESS_ACCT
+if [ "$CONFIG_X86_TSC" = "y" ]; then
+ bool 'Precise accounting' CONFIG_PRECISE_ACCT
+fi
bool 'Sysctl support' CONFIG_SYSCTL
if [ "$CONFIG_PROC_FS" = "y" ]; then
choice 'Kernel core (/proc/kcore) format' \
diff -ur linux-2.4.20/arch/i386/kernel/apic.c linux-2.4.20-pa/arch/i386/kernel/apic.c
--- linux-2.4.20/arch/i386/kernel/apic.c Fri Nov 29 00:53:09 2002
+++ linux-2.4.20-pa/arch/i386/kernel/apic.c Tue Feb 4 10:11:58 2003
@@ -38,6 +38,8 @@
int prof_old_multiplier[NR_CPUS] = { 1, };
int prof_counter[NR_CPUS] = { 1, };

+extern unsigned long cycles_per_jiffie;
+
int get_maxlvt(void)
{
unsigned int v, ver, maxlvt;
@@ -910,6 +912,8 @@
printk("..... host bus clock speed is %ld.%04ld MHz.\n",
result/(1000000/HZ),
result%(1000000/HZ));
+
+ cycles_per_jiffie = (long)(t2-t1)/LOOPS;

return result;
}
diff -ur linux-2.4.20/arch/i386/kernel/irq.c linux-2.4.20-pa/arch/i386/kernel/irq.c
--- linux-2.4.20/arch/i386/kernel/irq.c Fri Nov 29 00:53:09 2002
+++ linux-2.4.20-pa/arch/i386/kernel/irq.c Tue Feb 4 10:13:48 2003
@@ -183,6 +183,70 @@
}


+#ifdef CONFIG_PRECISE_ACCT
+int get_irq_cycles_list(char *buf)
+{
+ int i, j;
+ struct irqaction * action;
+ char *p = buf;
+
+ p += sprintf(p, " ");
+ for (j=0; j<smp_num_cpus; j++)
+ p += sprintf(p, " CPU%d ",j);
+ *p++ = '\n';
+
+ for (i = 0 ; i < NR_IRQS ; i++) {
+ action = irq_desc[i].action;
+ if (!action)
+ continue;
+ p += sprintf(p, " %3d: ",i);
+ for (j = 0; j < smp_num_cpus; j++)
+ p += sprintf(p, "%20Lu ",
+ kstat.irq_cycles[cpu_logical_map(j)][i]);
+ p += sprintf(p, " %14s", irq_desc[i].handler->typename);
+ p += sprintf(p, " %s", action->name);
+
+ for (action=action->next; action; action = action->next)
+ p += sprintf(p, ", %s", action->name);
+ *p++ = '\n';
+ }
+ p += sprintf(p, " HI_SOFTIRQ: ");
+ for (j = 0; j < smp_num_cpus; j++)
+ p += sprintf(p, "%20Lu ",
+ kstat.softirq_used_cycles[cpu_logical_map(j)][ HI_SOFTIRQ ] );
+ p += sprintf(p, "\n");
+ p += sprintf(p, " NET_TX_SOFTIRQ: ");
+ for (j = 0; j < smp_num_cpus; j++)
+ p += sprintf(p, "%20Lu ",
+ kstat.softirq_used_cycles[cpu_logical_map(j)][ NET_TX_SOFTIRQ ] );
+ p += sprintf(p, "\n");
+ p += sprintf(p, " NET_RX_SOFTIRQ: ");
+ for (j = 0; j < smp_num_cpus; j++)
+ p += sprintf(p, "%20Lu ",
+ kstat.softirq_used_cycles[cpu_logical_map(j)][ NET_RX_SOFTIRQ ] );
+ p += sprintf(p, "\n");
+ p += sprintf(p, "TASKLET_SOFTIRQ: ");
+ for (j = 0; j < smp_num_cpus; j++)
+ p += sprintf(p, "%20Lu ",
+ kstat.softirq_used_cycles[cpu_logical_map(j)][ TASKLET_SOFTIRQ ] );
+ p += sprintf(p, "\n");
+ i = 0;
+ for (j = 0; j < smp_num_cpus; j++)
+ if ( kstat.softirq_used_cycles[cpu_logical_map(j)][ TASKLET_SOFTIRQ+1 ] )
+ i = 1;
+ if ( i )
+ {
+ p += sprintf(p, "SOFTIRQ_OTHER: ");
+ for (j = 0; j < smp_num_cpus; j++)
+ p += sprintf(p, "%20Lu ",
+ kstat.softirq_used_cycles[cpu_logical_map(j)][ TASKLET_SOFTIRQ+1 ] );
+ p += sprintf(p, "\n");
+ }
+ return p - buf;
+}
+#endif
+
+
/*
* Global interrupt locks for SMP. Allow interrupts to come in on any
* CPU, yet make cli/sti act globally to protect critical regions..
@@ -577,6 +641,9 @@
irq_desc_t *desc = irq_desc + irq;
struct irqaction * action;
unsigned int status;
+#ifdef CONFIG_PRECISE_ACCT
+ cycles_t td, t = get_cycles();
+#endif
#ifdef CONFIG_DEBUG_STACKOVERFLOW
long esp;

@@ -650,6 +717,12 @@
*/
desc->handler->end(irq);
spin_unlock(&desc->lock);
+
+#ifdef CONFIG_PRECISE_ACCT
+ td = get_cycles()-t;
+ last_cycles[cpu] += td;
+ kstat.irq_cycles[cpu][irq] += td;
+#endif

if (softirq_pending(cpu))
do_softirq();
diff -ur linux-2.4.20/arch/i386/kernel/time.c linux-2.4.20-pa/arch/i386/kernel/time.c
--- linux-2.4.20/arch/i386/kernel/time.c Fri Nov 29 00:53:09 2002
+++ linux-2.4.20-pa/arch/i386/kernel/time.c Tue Feb 4 10:11:58 2003
@@ -67,6 +67,8 @@

unsigned long cpu_khz; /* Detected as we calibrate the TSC */

+extern unsigned long cycles_per_jiffie;
+
/* Number of usecs that the last interrupt was delayed */
static int delay_at_last_interrupt;

@@ -695,6 +697,13 @@
:"r" (tsc_quotient),
"0" (eax), "1" (edx));
printk("Detected %lu.%03lu MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000);
+
+ eax = 0;
+ edx = 1000000/HZ;
+ __asm__("divl %2"
+ :"=a" (cycles_per_jiffie), "=d" (edx)
+ :"r" (tsc_quotient),
+ "0" (eax), "1" (edx));
}
}
}
diff -ur linux-2.4.20/fs/proc/array.c linux-2.4.20-pa/fs/proc/array.c
--- linux-2.4.20/fs/proc/array.c Sat Aug 3 02:39:45 2002
+++ linux-2.4.20-pa/fs/proc/array.c Tue Feb 4 10:11:58 2003
@@ -307,6 +307,11 @@
int res;
pid_t ppid;
struct mm_struct *mm;
+#ifdef CONFIG_PRECISE_ACCT
+ cycles_t tot_cycles = 0;
+ int i;
+#endif
+

state = *get_task_state(task);
vsize = eip = esp = 0;
@@ -318,6 +323,12 @@
tty_pgrp = task->tty->pgrp;
tty_nr = kdev_t_to_nr(task->tty->device);
}
+
+#ifdef CONFIG_PRECISE_ACCT
+ for (i = 0 ; i < smp_num_cpus; i++) {
+ tot_cycles += task->cycles[cpu_logical_map(i)];
+ }
+#endif
task_unlock(task);
if (mm) {
struct vm_area_struct *vma;
@@ -391,6 +402,16 @@
task->cnswap,
task->exit_signal,
task->processor);
+#ifdef CONFIG_PRECISE_ACCT
+ res += sprintf( buffer+res,
+ "cycles " );
+ for (i = 0 ; i < smp_num_cpus; i++) {
+ res += sprintf( buffer+res,
+ "%Lu ", task->cycles[cpu_logical_map(i)] );
+ }
+ res += sprintf( buffer+res,
+ "%Lu\n", tot_cycles );
+#endif
if(mm)
mmput(mm);
return res;
@@ -682,6 +703,15 @@
int proc_pid_cpu(struct task_struct *task, char * buffer)
{
int i, len;
+#ifdef CONFIG_PRECISE_ACCT
+ cycles_t tot_cycles = 0;
+#endif
+
+#ifdef CONFIG_PRECISE_ACCT
+ for (i = 0 ; i < smp_num_cpus; i++) {
+ tot_cycles += task->cycles[cpu_logical_map(i)];
+ }
+#endif

len = sprintf(buffer,
"cpu %lu %lu\n",
@@ -693,6 +723,16 @@
i,
task->per_cpu_utime[cpu_logical_map(i)],
task->per_cpu_stime[cpu_logical_map(i)]);
+
+#ifdef CONFIG_PRECISE_ACCT
+ len += sprintf( buffer+len,
+ "cycles %Lu\n", tot_cycles );
+ for (i = 0 ; i < smp_num_cpus; i++) {
+ len += sprintf( buffer+len,
+ "cycles%d %Lu\n",
+ i, task->cycles[cpu_logical_map(i)] );
+ }
+#endif

return len;
}
diff -ur linux-2.4.20/fs/proc/proc_misc.c linux-2.4.20-pa/fs/proc/proc_misc.c
--- linux-2.4.20/fs/proc/proc_misc.c Fri Nov 29 00:53:15 2002
+++ linux-2.4.20-pa/fs/proc/proc_misc.c Tue Feb 4 10:16:39 2003
@@ -308,6 +308,11 @@
unsigned long jif = jiffies;
unsigned int sum = 0, user = 0, nice = 0, system = 0;
int major, disk;
+#ifdef CONFIG_PRECISE_ACCT
+ unsigned long long used_cycles_tot = 0, tot_cycles_tot = 0, irq_cycles_tot = 0, softirq_cycles_tot = 0;
+ unsigned long long irq_cycles_cpu[ NR_CPUS ] = { 0 };
+ unsigned long long softirq_cycles_cpu[ NR_CPUS ] = { 0 };
+#endif

for (i = 0 ; i < smp_num_cpus; i++) {
int cpu = cpu_logical_map(i), j;
@@ -317,7 +322,20 @@
system += kstat.per_cpu_system[cpu];
#if !defined(CONFIG_ARCH_S390)
for (j = 0 ; j < NR_IRQS ; j++)
+ {
sum += kstat.irqs[cpu][j];
+#ifdef CONFIG_PRECISE_ACCT
+ irq_cycles_cpu[cpu] += kstat.irq_cycles[cpu][j];
+#endif
+ }
+#endif
+#ifdef CONFIG_PRECISE_ACCT
+ used_cycles_tot += kstat.used_cycles[cpu];
+ tot_cycles_tot += last_cycles[cpu];
+ irq_cycles_tot += irq_cycles_cpu[cpu];
+ for ( j = 0; j < TASKLET_SOFTIRQ+2; j++ )
+ softirq_cycles_cpu[cpu] += kstat.softirq_used_cycles[cpu][j];
+ softirq_cycles_tot += softirq_cycles_cpu[cpu];
#endif
}

@@ -333,7 +351,22 @@
kstat.per_cpu_system[cpu_logical_map(i)],
jif - ( kstat.per_cpu_user[cpu_logical_map(i)] \
+ kstat.per_cpu_nice[cpu_logical_map(i)] \
- + kstat.per_cpu_system[cpu_logical_map(i)]));
+ + kstat.per_cpu_system[cpu_logical_map(i)]));
+#ifdef CONFIG_PRECISE_ACCT
+ len += sprintf(page + len,
+ "cycles %Lu %Lu %Lu %Lu %Lu\n", used_cycles_tot, irq_cycles_tot, softirq_cycles_tot,
+ tot_cycles_tot - used_cycles_tot - irq_cycles_tot - softirq_cycles_tot, tot_cycles_tot );
+ for (i = 0 ; i < smp_num_cpus; i++)
+ proc_sprintf(page, &off, &len,
+ "cycles%d %Lu %Lu %Lu %Lu %Lu\n",
+ i,
+ kstat.used_cycles[cpu_logical_map(i)],
+ irq_cycles_cpu[cpu_logical_map(i)],
+ softirq_cycles_cpu[cpu_logical_map(i)],
+ last_cycles[cpu_logical_map(i)] - kstat.used_cycles[cpu_logical_map(i)]
+ - irq_cycles_cpu[cpu_logical_map(i)] - softirq_cycles_cpu[cpu_logical_map(i)],
+ last_cycles[cpu_logical_map(i)] );
+#endif
proc_sprintf(page, &off, &len,
"page %u %u\n"
"swap %u %u\n"
@@ -397,6 +430,17 @@
}
#endif

+#if !defined(CONFIG_ARCH_S390)
+#ifdef CONFIG_PRECISE_ACCT
+static int interrupts_cycles_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = get_irq_cycles_list(page);
+ return proc_calc_metrics(page, start, off, count, eof, len);
+}
+#endif
+#endif
+
static int filesystems_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
@@ -566,6 +610,9 @@
{"devices", devices_read_proc},
#if !defined(CONFIG_ARCH_S390)
{"interrupts", interrupts_read_proc},
+#ifdef CONFIG_PRECISE_ACCT
+ {"interrupts_cycles", interrupts_cycles_read_proc},
+#endif
#endif
{"filesystems", filesystems_read_proc},
{"dma", dma_read_proc},
diff -ur linux-2.4.20/include/linux/kernel_stat.h linux-2.4.20-pa/include/linux/kernel_stat.h
--- linux-2.4.20/include/linux/kernel_stat.h Tue Feb 4 09:44:10 2003
+++ linux-2.4.20-pa/include/linux/kernel_stat.h Tue Feb 4 10:22:12 2003
@@ -5,6 +5,9 @@
#include <asm/irq.h>
#include <linux/smp.h>
#include <linux/threads.h>
+#ifdef CONFIG_PRECISE_ACCT
+#include <linux/interrupt.h>
+#endif

/*
* 'kernel_stat.h' contains the definitions needed for doing
@@ -15,10 +18,18 @@
#define DK_MAX_MAJOR 16
#define DK_MAX_DISK 16

+
struct kernel_stat {
unsigned int per_cpu_user[NR_CPUS],
per_cpu_nice[NR_CPUS],
per_cpu_system[NR_CPUS];
+#ifdef CONFIG_PRECISE_ACCT
+ cycles_t used_cycles[NR_CPUS];
+#if !defined(CONFIG_ARCH_S390)
+ cycles_t irq_cycles[NR_CPUS][NR_IRQS];
+#endif
+ cycles_t softirq_used_cycles[NR_CPUS][TASKLET_SOFTIRQ+2];
+#endif
unsigned int dk_drive[DK_MAX_MAJOR][DK_MAX_DISK];
unsigned int dk_drive_rio[DK_MAX_MAJOR][DK_MAX_DISK];
unsigned int dk_drive_wio[DK_MAX_MAJOR][DK_MAX_DISK];
diff -ur linux-2.4.20/include/linux/sched.h linux-2.4.20-pa/include/linux/sched.h
--- linux-2.4.20/include/linux/sched.h Tue Feb 4 09:44:10 2003
+++ linux-2.4.20-pa/include/linux/sched.h Tue Feb 4 10:22:07 2003
@@ -112,6 +112,9 @@
__set_current_state(state_value)
#endif

+extern cycles_t last_cycles[NR_CPUS];
+
+
/*
* Scheduling policies
*/
@@ -365,6 +368,7 @@
unsigned long it_real_incr, it_prof_incr, it_virt_incr;
struct timer_list real_timer;
struct tms times;
+ cycles_t cycles[NR_CPUS];
unsigned long start_time;
long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS];
/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
diff -ur linux-2.4.20/kernel/fork.c linux-2.4.20-pa/kernel/fork.c
--- linux-2.4.20/kernel/fork.c Fri Nov 29 00:53:15 2002
+++ linux-2.4.20-pa/kernel/fork.c Tue Feb 4 10:11:58 2003
@@ -580,6 +580,7 @@
int retval;
struct task_struct *p;
struct completion vfork;
+ int i;

if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
return -EINVAL;
@@ -662,6 +663,8 @@
p->tty_old_pgrp = 0;
p->times.tms_utime = p->times.tms_stime = 0;
p->times.tms_cutime = p->times.tms_cstime = 0;
+ for ( i = 0; i < NR_CPUS; i++ )
+ p->cycles[i] = 0;
#ifdef CONFIG_SMP
{
int i;
diff -ur linux-2.4.20/kernel/sched.c linux-2.4.20-pa/kernel/sched.c
--- linux-2.4.20/kernel/sched.c Fri Nov 29 00:53:15 2002
+++ linux-2.4.20-pa/kernel/sched.c Tue Feb 4 10:11:58 2003
@@ -36,6 +36,10 @@
extern void timer_bh(void);
extern void tqueue_bh(void);
extern void immediate_bh(void);
+#ifdef CONFIG_PRECISE_ACCT
+extern void update_process_cylces(void);
+#endif
+extern cycles_t last_cycles[NR_CPUS];

/*
* scheduler variables
@@ -625,6 +629,10 @@
goto repeat_schedule;
}

+#ifdef CONFIG_PRECISE_ACCT
+ if (prev != next)
+ update_process_cycles();
+#endif
/*
* from this point on nothing can prevent us from
* switching to the next task, save this fact in
@@ -1327,6 +1335,8 @@
sched_data->curr = current;
sched_data->last_schedule = get_cycles();
clear_bit(current->processor, &wait_init_idle);
+
+ last_cycles[smp_processor_id()] = get_cycles();
}

extern void init_timervecs (void);
diff -ur linux-2.4.20/kernel/softirq.c linux-2.4.20-pa/kernel/softirq.c
--- linux-2.4.20/kernel/softirq.c Fri Nov 29 00:53:15 2002
+++ linux-2.4.20-pa/kernel/softirq.c Tue Feb 4 10:11:58 2003
@@ -64,6 +64,10 @@
__u32 pending;
unsigned long flags;
__u32 mask;
+#ifdef CONFIG_PRECISE_ACCT
+ cycles_t td, t = get_cycles();
+ unsigned n;
+#endif

if (in_interrupt())
return;
@@ -80,16 +84,34 @@
restart:
/* Reset the pending bitmask before enabling irqs */
softirq_pending(cpu) = 0;
-
+#ifdef CONFIG_PRECISE_ACCT
+ n = 0;
+#endif
local_irq_enable();

h = softirq_vec;

do {
if (pending & 1)
+ {
+#ifdef CONFIG_PRECISE_ACCT
+ t = get_cycles();
+#endif
h->action(h);
+#ifdef CONFIG_PRECISE_ACCT
+ td = get_cycles()-t;
+ last_cycles[cpu] += td;
+ if ( n <= TASKLET_SOFTIRQ )
+ kstat.softirq_used_cycles[cpu][n] += td;
+ else
+ kstat.softirq_used_cycles[cpu][TASKLET_SOFTIRQ+1] += td;
+#endif
+ }
h++;
pending >>= 1;
+#ifdef CONFIG_PRECISE_ACCT
+ n++;
+#endif
} while (pending);

local_irq_disable();
diff -ur linux-2.4.20/kernel/timer.c linux-2.4.20-pa/kernel/timer.c
--- linux-2.4.20/kernel/timer.c Fri Nov 29 00:53:15 2002
+++ linux-2.4.20-pa/kernel/timer.c Tue Feb 4 10:11:58 2003
@@ -64,6 +64,9 @@
unsigned long event;

extern int do_setitimer(int, struct itimerval *, struct itimerval *);
+#ifdef CONFIG_PRECISE_ACCT
+extern void update_process_cycles(void);
+#endif

unsigned long volatile jiffies;

@@ -71,6 +74,9 @@
unsigned long prof_len;
unsigned long prof_shift;

+unsigned long cycles_per_jiffie = 0;
+cycles_t last_cycles[NR_CPUS];
+
/*
* Event timer code
*/
@@ -618,6 +624,24 @@
} else if (local_bh_count(cpu) || local_irq_count(cpu) > 1)
kstat.per_cpu_system[cpu] += system;
}
+
+/*
+ * Called from the scheduler.
+ */
+#ifdef CONFIG_PRECISE_ACCT
+void update_process_cycles(void)
+{
+ struct task_struct *p = current;
+ int cpu = smp_processor_id();
+ cycles_t t = get_cycles();
+
+ p->cycles[cpu] += t - last_cycles[cpu];
+ if ( p->pid )
+ kstat.used_cycles[cpu] += t - last_cycles[cpu];
+ last_cycles[cpu] = t;
+
+}
+#endif

/*
* Nr of active tasks - counted in fixed-point numbers
-----------------------------8<------------------------------------
-
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/

\
 
 \ /
  Last update: 2005-03-22 13:33    [W:0.029 / U:19.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site