Revision 9107c89e269d2738019861bb518e3d59bef01781 authored by Peter Zijlstra on 24 February 2016, 17:45:45 UTC, committed by Ingo Molnar on 25 February 2016, 07:42:34 UTC
perf_install_in_context() relies upon the context switch hooks to have scheduled in events when the IPI misses its target -- after all, if the task has moved from the CPU (or wasn't running at all), it will have to context switch to run elsewhere. This however doesn't appear to be happening. It is possible for the IPI to not happen (task wasn't running) only to later observe the task running with an inactive context. The only possible explanation is that the context switch hooks are not called. Therefore put in a sync_sched() after toggling the jump_label to guarantee all CPUs will have them enabled before we install an event. A simple if (0->1) sync_sched() will not in fact work, because any further increment can race and complete before the sync_sched(). Therefore we must jump through some hoops. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.980211985@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent a69b0ca
udftime.c
/* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Eggert (eggert@twinsun.com).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/*
* dgb 10/02/98: ripped this from glibc source to help convert timestamps
* to unix time
* 10/04/98: added new table-based lookup after seeing how ugly
* the gnu code is
* blf 09/27/99: ripped out all the old code and inserted new table from
* John Brockmeyer (without leap second corrections)
* rewrote udf_stamp_to_time and fixed timezone accounting in
* udf_time_to_stamp.
*/
/*
* We don't take into account leap seconds. This may be correct or incorrect.
* For more NIST information (especially dealing with leap seconds), see:
* http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
*/
#include "udfdecl.h"
#include <linux/types.h>
#include <linux/kernel.h>
#define EPOCH_YEAR 1970
#ifndef __isleap
/* Nonzero if YEAR is a leap year (every 4 years,
except every 100th isn't, and every 400th is). */
#define __isleap(year) \
((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
#endif
/* How many days come before each month (0-12). */
static const unsigned short int __mon_yday[2][13] = {
/* Normal years. */
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
/* Leap years. */
{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
};
#define MAX_YEAR_SECONDS 69
#define SPD 0x15180 /*3600*24 */
#define SPY(y, l, s) (SPD * (365 * y + l) + s)
static time_t year_seconds[MAX_YEAR_SECONDS] = {
/*1970*/ SPY(0, 0, 0), SPY(1, 0, 0), SPY(2, 0, 0), SPY(3, 1, 0),
/*1974*/ SPY(4, 1, 0), SPY(5, 1, 0), SPY(6, 1, 0), SPY(7, 2, 0),
/*1978*/ SPY(8, 2, 0), SPY(9, 2, 0), SPY(10, 2, 0), SPY(11, 3, 0),
/*1982*/ SPY(12, 3, 0), SPY(13, 3, 0), SPY(14, 3, 0), SPY(15, 4, 0),
/*1986*/ SPY(16, 4, 0), SPY(17, 4, 0), SPY(18, 4, 0), SPY(19, 5, 0),
/*1990*/ SPY(20, 5, 0), SPY(21, 5, 0), SPY(22, 5, 0), SPY(23, 6, 0),
/*1994*/ SPY(24, 6, 0), SPY(25, 6, 0), SPY(26, 6, 0), SPY(27, 7, 0),
/*1998*/ SPY(28, 7, 0), SPY(29, 7, 0), SPY(30, 7, 0), SPY(31, 8, 0),
/*2002*/ SPY(32, 8, 0), SPY(33, 8, 0), SPY(34, 8, 0), SPY(35, 9, 0),
/*2006*/ SPY(36, 9, 0), SPY(37, 9, 0), SPY(38, 9, 0), SPY(39, 10, 0),
/*2010*/ SPY(40, 10, 0), SPY(41, 10, 0), SPY(42, 10, 0), SPY(43, 11, 0),
/*2014*/ SPY(44, 11, 0), SPY(45, 11, 0), SPY(46, 11, 0), SPY(47, 12, 0),
/*2018*/ SPY(48, 12, 0), SPY(49, 12, 0), SPY(50, 12, 0), SPY(51, 13, 0),
/*2022*/ SPY(52, 13, 0), SPY(53, 13, 0), SPY(54, 13, 0), SPY(55, 14, 0),
/*2026*/ SPY(56, 14, 0), SPY(57, 14, 0), SPY(58, 14, 0), SPY(59, 15, 0),
/*2030*/ SPY(60, 15, 0), SPY(61, 15, 0), SPY(62, 15, 0), SPY(63, 16, 0),
/*2034*/ SPY(64, 16, 0), SPY(65, 16, 0), SPY(66, 16, 0), SPY(67, 17, 0),
/*2038*/ SPY(68, 17, 0)
};
#define SECS_PER_HOUR (60 * 60)
#define SECS_PER_DAY (SECS_PER_HOUR * 24)
struct timespec *
udf_disk_stamp_to_time(struct timespec *dest, struct timestamp src)
{
int yday;
u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone);
u16 year = le16_to_cpu(src.year);
uint8_t type = typeAndTimezone >> 12;
int16_t offset;
if (type == 1) {
offset = typeAndTimezone << 4;
/* sign extent offset */
offset = (offset >> 4);
if (offset == -2047) /* unspecified offset */
offset = 0;
} else
offset = 0;
if ((year < EPOCH_YEAR) ||
(year >= EPOCH_YEAR + MAX_YEAR_SECONDS)) {
return NULL;
}
dest->tv_sec = year_seconds[year - EPOCH_YEAR];
dest->tv_sec -= offset * 60;
yday = ((__mon_yday[__isleap(year)][src.month - 1]) + src.day - 1);
dest->tv_sec += (((yday * 24) + src.hour) * 60 + src.minute) * 60 + src.second;
dest->tv_nsec = 1000 * (src.centiseconds * 10000 +
src.hundredsOfMicroseconds * 100 + src.microseconds);
return dest;
}
struct timestamp *
udf_time_to_disk_stamp(struct timestamp *dest, struct timespec ts)
{
long int days, rem, y;
const unsigned short int *ip;
int16_t offset;
offset = -sys_tz.tz_minuteswest;
if (!dest)
return NULL;
dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF));
ts.tv_sec += offset * 60;
days = ts.tv_sec / SECS_PER_DAY;
rem = ts.tv_sec % SECS_PER_DAY;
dest->hour = rem / SECS_PER_HOUR;
rem %= SECS_PER_HOUR;
dest->minute = rem / 60;
dest->second = rem % 60;
y = 1970;
#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
while (days < 0 || days >= (__isleap(y) ? 366 : 365)) {
long int yg = y + days / 365 - (days % 365 < 0);
/* Adjust DAYS and Y to match the guessed year. */
days -= ((yg - y) * 365
+ LEAPS_THRU_END_OF(yg - 1)
- LEAPS_THRU_END_OF(y - 1));
y = yg;
}
dest->year = cpu_to_le16(y);
ip = __mon_yday[__isleap(y)];
for (y = 11; days < (long int)ip[y]; --y)
continue;
days -= ip[y];
dest->month = y + 1;
dest->day = days + 1;
dest->centiseconds = ts.tv_nsec / 10000000;
dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 -
dest->centiseconds * 10000) / 100;
dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 -
dest->hundredsOfMicroseconds * 100);
return dest;
}
/* EOF */
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