/*
* Mausezahn - A fast versatile traffic generator
* Copyright (C) 2008-2010 Herbert Haas
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation.
*
* This program 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 General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, see http://www.gnu.org/licenses/gpl-2.0.html
*
*/
#include "mz.h"
// Check if current system supports the nanosecond timer functions.
// Additionally, measure the precision.
// This function should be called upon program start.
//
int check_timer(void)
{
struct timespec res;
int r;
// Check if the glibc is recent enough:
#ifdef _POSIX_C_SOURCE
if (_POSIX_C_SOURCE >= 199309L) {
r = clock_getres(CLOCK_MONOTONIC, &res);
if (r!=0) perror(" mz/check_timer:");
if (verbose) {
fprintf(stderr, " This system supports a high resolution clock.\n");
fprintf(stderr, " The clock resolution is %li nanoseconds.\n",
res.tv_nsec);
}
}
else {
fprintf(stderr,
" WARNING: Your system does NOT support the newer high resolution clock\n"
" Please inform the author: herbert@perihel.at\n");
exit(1);
}
#endif
return 0;
}
// This is the replacement for gettimeofday() which would result in 'jumps' if
// the system clock is adjusted (e. g. via a NTP process) and finally the jitter
// measurement would include wrong datapoints.
//
// Furthermore the function below utilizes the newer hi-res nanosecond timers.
inline void getcurtime (struct mz_timestamp *t)
{
struct timespec ct;
clock_gettime(CLOCK_MONOTONIC, &ct);
t->sec = ct.tv_sec;
t->nsec = ct.tv_nsec;
}
//////////////////////////////////////////////////////////////////////////////////////
// Purpose: Calculate time deltas of two timestamps stored in struct timeval.
//
// Subtract the "struct timeval" values X and Y, storing the result in RESULT,
// i. e. X-Y=RESULT.
//
// RETURN VALUES:
//
// Sign: 1 = negative, 0 = positive
// Error: -1 due to a wrong timestamp (i. e. nsec > 999999999L)
//
inline int timestamp_subtract (struct mz_timestamp *x, struct mz_timestamp *y, struct mz_timestamp *result)
{
int32_t ndiff;
int sign=0, carry=0;
// Check for wrong timestamps
if ((x->nsec>999999999L) || (y->nsec>999999999L)) return -1;
if (y->sec > x->sec) sign=1;
else if ((y->sec == x->sec) && (y->nsec > x->nsec)) sign=1;
ndiff = x->nsec - y->nsec;
if ((ndiff>0) && (sign)) carry=1;
if ((ndiff<0) && (sign)) ndiff = y->nsec - x->nsec;
if ((ndiff<0) && (!sign)) {
ndiff = 1000000000L + ndiff;
carry=1;
}
if (sign)
result->sec = y->sec - x->sec - carry;
else
result->sec = x->sec - y->sec - carry;
result->nsec = ndiff;
return sign;
}
// Add two variables of type struct mz_timestamp: x+y=result.
//
inline void timestamp_add (struct mz_timestamp *x, struct mz_timestamp *y, struct mz_timestamp *result)
{
int carry=0;
u_int32_t c;
c = x->nsec + y->nsec;
if (c>999999999L) {
carry=1;
result->nsec =c-1000000000;
} else result->nsec =c;
result->sec = x->sec + y->sec + carry;
}
// Returns a human readable timestamp in the string result.
// Optionally a prefix can be specified, for example if the
// timestamp is part of a filename.
//
// Example:
// char myTimeStamp[128];
//
// timestamp_human(myTimeStamp, NULL);
//
// => "20080718_155521"
//
// /* or with prefix */
//
// timestamp_human(myTimeStamp, "MZ_RTP_jitter_");
//
// => "MZ_RTP_jitter_20080718_155521"
//
int timestamp_human(char* result, const char* prefix)
{
time_t curtime;
struct tm curtime_broken;
char curtime_str[32];
time(&curtime);
localtime_r (&curtime, &curtime_broken);
sprintf(curtime_str, "%4i%02i%02i-%02i%02i%02i",
curtime_broken.tm_year+1900,
curtime_broken.tm_mon+1,
curtime_broken.tm_mday,
curtime_broken.tm_hour,
curtime_broken.tm_min,
curtime_broken.tm_sec);
if (prefix==NULL)
{
strncpy(result, curtime_str, 32);
}
else
{
strncpy(result, prefix, 32);
strncat(result, curtime_str, 32);
}
return 0;
}
// Creates a human readable timestamp in the string result.
// Optionally a prefix can be specified, for example if the
// timestamp is part of a filename.
//
// Example:
// char myTimeStamp[9];
//
// timestamp_hms (myTimeStamp);
//
// => "15:55:21"
int timestamp_hms(char* result)
{
time_t curtime;
struct tm curtime_broken;
char curtime_str[32];
time(&curtime);
localtime_r (&curtime, &curtime_broken);
sprintf(curtime_str, "%02i:%02i:%02i",
curtime_broken.tm_hour,
curtime_broken.tm_min,
curtime_broken.tm_sec);
strncpy(result, curtime_str, 9);
return 0;
}
ption value='0' selected='selected'>unified
Snooze is a poll idle state in powernv and pseries platforms. Snooze
has a timeout so that if a CPU stays in snooze for more than target
residency of the next available idle state, then it would exit
thereby giving chance to the cpuidle governor to re-evaluate and
promote the CPU to a deeper idle state. Therefore whenever snooze
exits due to this timeout, its last_residency will be target_residency
of the next deeper state.
Commit e93e59ce5b85 "cpuidle: Replace ktime_get() with local_clock()"
changed the math around last_residency calculation. Specifically,
while converting last_residency value from nano- to microseconds, it
carries out right shift by 10. Because of that, in snooze timeout
exit scenarios last_residency calculated is roughly 2.3% less than
target_residency of the next available state. This pattern is picked
up by get_typical_interval() in the menu governor and therefore
expected_interval in menu_select() is frequently less than the
target_residency of any state other than snooze.
Due to this we are entering snooze at a higher rate, thereby
affecting the single thread performance.
Fix this by using more precise division via ktime_us_delta().
Fixes: e93e59ce5b85 "cpuidle: Replace ktime_get() with local_clock()"
Reported-by: Anton Blanchard <anton@samba.org>
Bisected-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/devicetree/bindings/memory-controllers')