mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
![Yuyang Du](/assets/img/avatar_default.png)
Add a user-space program to compute/generate the PELT constants. The kernel/sched/sched-pelt.h header will contain the output of this program. Signed-off-by: Yuyang Du <yuyang.du@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: matt@codeblueprint.co.uk Cc: morten.rasmussen@arm.com Cc: pjt@google.com Cc: umgwanakikbuti@gmail.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1486935863-25251-2-git-send-email-yuyang.du@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
108 lines
1.9 KiB
C
108 lines
1.9 KiB
C
/*
|
|
* The following program is used to generate the constants for
|
|
* computing sched averages.
|
|
*
|
|
* ==============================================================
|
|
* C program (compile with -lm)
|
|
* ==============================================================
|
|
*/
|
|
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
|
|
#define HALFLIFE 32
|
|
#define SHIFT 32
|
|
|
|
double y;
|
|
|
|
void calc_runnable_avg_yN_inv(void)
|
|
{
|
|
int i;
|
|
unsigned int x;
|
|
|
|
printf("static const u32 runnable_avg_yN_inv[] = {");
|
|
for (i = 0; i < HALFLIFE; i++) {
|
|
x = ((1UL<<32)-1)*pow(y, i);
|
|
|
|
if (i % 6 == 0) printf("\n\t");
|
|
printf("0x%8x, ", x);
|
|
}
|
|
printf("\n};\n\n");
|
|
}
|
|
|
|
int sum = 1024;
|
|
|
|
void calc_runnable_avg_yN_sum(void)
|
|
{
|
|
int i;
|
|
|
|
printf("static const u32 runnable_avg_yN_sum[] = {\n\t 0,");
|
|
for (i = 1; i <= HALFLIFE; i++) {
|
|
if (i == 1)
|
|
sum *= y;
|
|
else
|
|
sum = sum*y + 1024*y;
|
|
|
|
if (i % 11 == 0)
|
|
printf("\n\t");
|
|
|
|
printf("%5d,", sum);
|
|
}
|
|
printf("\n};\n\n");
|
|
}
|
|
|
|
int n = -1;
|
|
/* first period */
|
|
long max = 1024;
|
|
|
|
void calc_converged_max(void)
|
|
{
|
|
long last = 0, y_inv = ((1UL<<32)-1)*y;
|
|
|
|
for (; ; n++) {
|
|
if (n > -1)
|
|
max = ((max*y_inv)>>SHIFT) + 1024;
|
|
/*
|
|
* This is the same as:
|
|
* max = max*y + 1024;
|
|
*/
|
|
|
|
if (last == max)
|
|
break;
|
|
|
|
last = max;
|
|
}
|
|
n--;
|
|
printf("#define LOAD_AVG_PERIOD %d\n", HALFLIFE);
|
|
printf("#define LOAD_AVG_MAX %ld\n", max);
|
|
// printf("#define LOAD_AVG_MAX_N %d\n\n", n);
|
|
}
|
|
|
|
void calc_accumulated_sum_32(void)
|
|
{
|
|
int i, x = sum;
|
|
|
|
printf("static const u32 __accumulated_sum_N32[] = {\n\t 0,");
|
|
for (i = 1; i <= n/HALFLIFE+1; i++) {
|
|
if (i > 1)
|
|
x = x/2 + sum;
|
|
|
|
if (i % 6 == 0)
|
|
printf("\n\t");
|
|
|
|
printf("%6d,", x);
|
|
}
|
|
printf("\n};\n\n");
|
|
}
|
|
|
|
void main(void)
|
|
{
|
|
printf("/* Generated by Documentation/scheduler/sched-pelt; do not modify. */\n\n");
|
|
|
|
y = pow(0.5, 1/(double)HALFLIFE);
|
|
|
|
calc_runnable_avg_yN_inv();
|
|
// calc_runnable_avg_yN_sum();
|
|
calc_converged_max();
|
|
// calc_accumulated_sum_32();
|
|
}
|