tas() has no users, so get rid of it.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This series extena and standardises local_t operations on each architecture,
allowing a rich set of atomic operations to be done on per-cpu data with
minimal performance impact. On architectures where there seems to be no
difference between the SMP and UP operation (same memory barriers, same
LOCKing), local.h simply includes asm-generic/local.h, which removes
duplicated code from the current kernel tree.
This patch:
local_t: architecture independent extension
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
I agree (with Andi Kleen) this typeof is not needed and more error
prone. All the original atomic.h code that uses cmpxchg (which includes
the atomic_add_unless) uses defines instead of inline functions,
probably to circumvent a circular dependency between system.h and
atomic.h on powerpc (which my patch addresses). Therefore, it makes
sense to use inline functions that will provide type checking.
atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
Digging into the FRV architecture shows me that it is also affected by
such a circular dependency. Here is the diff applying this against the
rest of my atomic.h patches.
It applies over the atomic.h standardization patches.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove an explicit cast to an integer type for the result returned by cmpxchg.
It is not per se a problem on the i386 architecture, because sizeof(int) ==
sizeof(long), but whenever this code is cut'n'pasted to a accept passing an
atomic64_t value as parameter to cmpxchg, xchg and add_unless, having 64 bits
inputs casted to 32 bits.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This series mainly adds support for missing 64 bits cmpxchg and 64 bits atomic
add unless. Therefore, principally 64 bits architectures are targeted by
these patches. It also adds the complete list of atomic operations on the
atomic_long type.
This patch:
atomic.h: add atomic64 cmpxchg, xchg and add_unless to alpha
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides a debugfs knob to turn kprobes on/off
o A new file /debug/kprobes/enabled indicates if kprobes is enabled or
not (default enabled)
o Echoing 0 to this file will disarm all installed probes
o Any new probe registration when disabled will register the probe but
not arm it. A message will be printed out in such a case.
o When a value 1 is echoed to the file, all probes (including ones
registered in the intervening period) will be enabled
o Unregistration will happen irrespective of whether probes are globally
enabled or not.
o Update Documentation/kprobes.txt to reflect these changes. While there
also update the doc to make it current.
We are also looking at providing sysrq key support to tie to the disabling
feature provided by this patch.
[akpm@linux-foundation.org: Use bool like a bool!]
[akpm@linux-foundation.org: add printk facility levels]
[cornelia.huck@de.ibm.com: Add the missing arch_trampoline_kprobe() for s390]
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- consolidate duplicate code in all arch_prepare_kretprobe instances
into common code
- replace various odd helpers that use hlist_for_each_entry to get
the first elemenet of a list with either a hlist_for_each_entry_save
or an opencoded access to the first element in the caller
- inline add_rp_inst into it's only remaining caller
- use kretprobe_inst_table_head instead of opencoding it
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace CONFIG_PNPACPI with CONFIG_PNP, so it loads on ACPI-less PNPBIOS
systems.
Signed-off-by: Marko Vrh <mvrh@freeshells.ch>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a common glitch in how RTC drivers handle two "set alarm" modes,
by getting rid of the surprising/hidden one that was rarely implemented
correctly (and which could expose nonportable hardware-specific behavior).
The glitch comes from the /dev/rtcX logic implementing the legacy
RTC_ALM_SET (limited to 24 hours, needing RTC_AIE_ON) ioctl on top of the
RTC driver call providing access to the newer RTC_WKALM_SET (without those
limitations) by initializing the day/month/year fields to be invalid ...
that second mode.
Now, since few RTC drivers check those fields, and most hardware misbehaves
when faced with invalid date fields, many RTC drivers will set bogus alarm
times on those RTC_ALM_SET code paths. (Several in-tree drivers have that
issue, and I also noticed it with code reviews on several new RTC drivers.)
This patch ensures that RTC drivers never see such invalid alarm fields, by
moving some logic out of rtc-omap into the RTC_ALM_SET code and adding an
explicit check (which will prevent the issue on other code paths).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David says "884b4aaaa242a2db8c8252796f0118164a680ab5 should be reverted. It
added an rtc_merge_alarm() call to the 2.6.20 kernel, which hasn't yet been
used by any in-tree driver; this patch obviates the need for that call, and
uses a more robust approach."
Cc: Scott Wood <scottwood@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This works around a bug seen in some RTC-related ACPI table entries, and
tweaks related diagnostics to follow the ACPI convention.
The bug prevents misleading boot-time messages: platforms affected by this
bug wrongly report they can support alarms up to one year in the future,
when in fact the longest alarm is just 24 hours. That will surprise anyone
trying to use those extended alarms.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove /proc/acpi/alarm file when the rtc-cmos "wakealarm" file is available.
Instead, provide hooks that rtc-cmos will use.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I finally got around to testing the updated wakeup event hooks for rtc-cmos,
and they follow in two patches:
- Interface update ... when a simple enable_irq_wake() doesn't suffice,
the platform data can hold suspend/resume callback hooks.
- ACPI implementation ... provides callback hooks to do ACPI magic, and
eliminate the legacy /proc/acpi/alarm file.
The interface update could go into 2.6.21, but that's not essential; they
will be NOPs on most PCs, without the ACPI stuff.
I suspect the ACPI folk may have opinions about how to merge that second
patch, and how to obsolete that legacy procfs file. I'd like to see that
merge into 2.6.22 if possible...
As for how to kick it in ... two ways:
- The appended "rtcwake" program; updated since the last time it was
posted, it deals much better with timezones and DST.
- Write the /sys/class/rtc/.../wakealarm file, then go to sleep.
For some reason RTC wake from "swsusp" stopped working on a system where
it previously worked; the alarm setting appears to get clobbered. But
on the bright side, RTC wake from "standby" worked on a system that had
never been able to resume from that state before ... IDEACPI is my guess
as to why it finally started to work. It's the old "two steps forward,
one step back" dance, I guess.
- Dave
/* gcc -Wall -Os -o rtcwake rtcwake.c */
#include <stdio.h>
#include <getopt.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <linux/rtc.h>
/* constants from legacy PC/AT hardware */
#define RTC_PF 0x40
#define RTC_AF 0x20
#define RTC_UF 0x10
/*
* rtcwake -- enter a system sleep state until specified wakeup time.
*
* This uses cross-platform Linux interfaces to enter a system sleep state,
* and leave it no later than a specified time. It uses any RTC framework
* driver that supports standard driver model wakeup flags.
*
* This is normally used like the old "apmsleep" utility, to wake from a
* suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most
* platforms can implement those without analogues of BIOS, APM, or ACPI.
*
* On some systems, this can also be used like "nvram-wakeup", waking
* from states like ACPI S4 (suspend to disk). Not all systems have
* persistent media that are appropriate for such suspend modes.
*
* The best way to set the system's RTC is so that it holds the current
* time in UTC. Use the "-l" flag to tell this program that the system
* RTC uses a local timezone instead (maybe you dual-boot MS-Windows).
*/
static char *progname;
#ifdef DEBUG
#define VERSION "1.0 dev (" __DATE__ " " __TIME__ ")"
#else
#define VERSION "0.9"
#endif
static unsigned verbose;
static int rtc_is_utc = -1;
static int may_wakeup(const char *devname)
{
char buf[128], *s;
FILE *f;
snprintf(buf, sizeof buf, "/sys/class/rtc/%s/device/power/wakeup",
devname);
f = fopen(buf, "r");
if (!f) {
perror(buf);
return 0;
}
fgets(buf, sizeof buf, f);
fclose(f);
s = strchr(buf, '\n');
if (!s)
return 0;
*s = 0;
/* wakeup events could be disabled or not supported */
return strcmp(buf, "enabled") == 0;
}
/* all times should be in UTC */
static time_t sys_time;
static time_t rtc_time;
static int get_basetimes(int fd)
{
struct tm tm;
struct rtc_time rtc;
/* this process works in RTC time, except when working
* with the system clock (which always uses UTC).
*/
if (rtc_is_utc)
setenv("TZ", "UTC", 1);
tzset();
/* read rtc and system clocks "at the same time", or as
* precisely (+/- a second) as we can read them.
*/
if (ioctl(fd, RTC_RD_TIME, &rtc) < 0) {
perror("read rtc time");
return 0;
}
sys_time = time(0);
if (sys_time == (time_t)-1) {
perror("read system time");
return 0;
}
/* convert rtc_time to normal arithmetic-friendly form,
* updating tm.tm_wday as used by asctime().
*/
memset(&tm, 0, sizeof tm);
tm.tm_sec = rtc.tm_sec;
tm.tm_min = rtc.tm_min;
tm.tm_hour = rtc.tm_hour;
tm.tm_mday = rtc.tm_mday;
tm.tm_mon = rtc.tm_mon;
tm.tm_year = rtc.tm_year;
tm.tm_isdst = rtc.tm_isdst; /* stays unspecified? */
rtc_time = mktime(&tm);
if (rtc_time == (time_t)-1) {
perror("convert rtc time");
return 0;
}
if (verbose) {
if (!rtc_is_utc) {
printf("\ttzone = %ld\n", timezone);
printf("\ttzname = %s\n", tzname[daylight]);
gmtime_r(&rtc_time, &tm);
}
printf("\tsystime = %ld, (UTC) %s",
(long) sys_time, asctime(gmtime(&sys_time)));
printf("\trtctime = %ld, (UTC) %s",
(long) rtc_time, asctime(&tm));
}
return 1;
}
static int setup_alarm(int fd, time_t *wakeup)
{
struct tm *tm;
struct rtc_wkalrm wake;
tm = gmtime(wakeup);
wake.time.tm_sec = tm->tm_sec;
wake.time.tm_min = tm->tm_min;
wake.time.tm_hour = tm->tm_hour;
wake.time.tm_mday = tm->tm_mday;
wake.time.tm_mon = tm->tm_mon;
wake.time.tm_year = tm->tm_year;
wake.time.tm_wday = tm->tm_wday;
wake.time.tm_yday = tm->tm_yday;
wake.time.tm_isdst = tm->tm_isdst;
/* many rtc alarms only support up to 24 hours from 'now' ... */
if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
if (ioctl(fd, RTC_ALM_SET, &wake.time) < 0) {
perror("set rtc alarm");
return 0;
}
if (ioctl(fd, RTC_AIE_ON, 0) < 0) {
perror("enable rtc alarm");
return 0;
}
/* ... so use the "more than 24 hours" request only if we must */
} else {
/* avoid an extra AIE_ON call */
wake.enabled = 1;
if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
perror("set rtc wake alarm");
return 0;
}
}
return 1;
}
static void suspend_system(const char *suspend)
{
FILE *f = fopen("/sys/power/state", "w");
if (!f) {
perror("/sys/power/state");
return;
}
fprintf(f, "%s\n", suspend);
fflush(f);
/* this executes after wake from suspend */
fclose(f);
}
int main(int argc, char **argv)
{
static char *devname = "rtc0";
static unsigned seconds = 0;
static char *suspend = "standby";
int t;
int fd;
time_t alarm = 0;
progname = strrchr(argv[0], '/');
if (progname)
progname++;
else
progname = argv[0];
if (chdir("/dev/") < 0) {
perror("chdir /dev");
return 1;
}
while ((t = getopt(argc, argv, "d:lm:s:t:uVv")) != EOF) {
switch (t) {
case 'd':
devname = optarg;
break;
case 'l':
rtc_is_utc = 0;
break;
/* what system power mode to use? for now handle only
* standardized mode names; eventually when systems define
* their own state names, parse /sys/power/state.
*
* "on" is used just to test the RTC alarm mechanism,
* bypassing all the wakeup-from-sleep infrastructure.
*/
case 'm':
if (strcmp(optarg, "standby") == 0
|| strcmp(optarg, "mem") == 0
|| strcmp(optarg, "disk") == 0
|| strcmp(optarg, "on") == 0
) {
suspend = optarg;
break;
}
printf("%s: unrecognized suspend state '%s'\n",
progname, optarg);
goto usage;
/* alarm time, seconds-to-sleep (relative) */
case 's':
t = atoi(optarg);
if (t < 0) {
printf("%s: illegal interval %s seconds\n",
progname, optarg);
goto usage;
}
seconds = t;
break;
/* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
case 't':
t = atoi(optarg);
if (t < 0) {
printf("%s: illegal time_t value %s\n",
progname, optarg);
goto usage;
}
alarm = t;
break;
case 'u':
rtc_is_utc = 1;
break;
case 'v':
verbose++;
break;
case 'V':
printf("%s: version %s\n", progname, VERSION);
break;
default:
usage:
printf("usage: %s [options]"
"\n\t"
"-d rtc0|rtc1|...\t(select rtc)"
"\n\t"
"-l\t\t\t(RTC uses local timezone)"
"\n\t"
"-m standby|mem|...\t(sleep mode)"
"\n\t"
"-s seconds\t\t(seconds to sleep)"
"\n\t"
"-t time_t\t\t(time to wake)"
"\n\t"
"-u\t\t\t(RTC uses UTC)"
"\n\t"
"-v\t\t\t(verbose messages)"
"\n\t"
"-V\t\t\t(show version)"
"\n",
progname);
return 1;
}
}
if (!alarm && !seconds) {
printf("%s: must provide wake time\n", progname);
goto usage;
}
/* REVISIT: if /etc/adjtime exists, read it to see what
* the util-linux version of hwclock assumes.
*/
if (rtc_is_utc == -1) {
printf("%s: assuming RTC uses UTC ...\n", progname);
rtc_is_utc = 1;
}
/* this RTC must exist and (if we'll sleep) be wakeup-enabled */
fd = open(devname, O_RDONLY);
if (fd < 0) {
perror(devname);
return 1;
}
if (strcmp(suspend, "on") != 0 && !may_wakeup(devname)) {
printf("%s: %s not enabled for wakeup events\n",
progname, devname);
return 1;
}
/* relative or absolute alarm time, normalized to time_t */
if (!get_basetimes(fd))
return 1;
if (verbose)
printf("alarm %ld, sys_time %ld, rtc_time %ld, seconds %u\n",
alarm, sys_time, rtc_time, seconds);
if (alarm) {
if (alarm < sys_time) {
printf("%s: time doesn't go backward to %s",
progname, ctime(&alarm));
return 1;
}
alarm += sys_time - rtc_time;
} else
alarm = rtc_time + seconds + 1;
if (setup_alarm(fd, &alarm) < 0)
return 1;
sync();
printf("%s: wakeup from \"%s\" using %s at %s",
progname, suspend, devname,
ctime(&alarm));
fflush(stdout);
usleep(10 * 1000);
if (strcmp(suspend, "on") != 0)
suspend_system(suspend);
else {
unsigned long data;
do {
t = read(fd, &data, sizeof data);
if (t < 0) {
perror("rtc read");
break;
}
if (verbose)
printf("... %s: %03lx\n", devname, data);
} while (!(data & RTC_AF));
}
if (ioctl(fd, RTC_AIE_OFF, 0) < 0)
perror("disable rtc alarm interrupt");
close(fd);
return 0;
}
This patch:
Make rtc-cmos do the relevant magic so this RTC can wake the system from a
sleep state. That magic comes in two basic flavors:
- Straightforward: enable_irq_wake(), the way it'd work on most SOC chips;
or generally with system sleep states which don't disable core IRQ logic.
- Roundabout, using non-IRQ platform hooks. This is needed with ACPI and
one almost-clone chip which uses a special wakeup-only alarm. (That's
the RTC used on Footbridge boards, FWIW, which don't do PM in Linux.)
A separate patch implements those hooks for ACPI platforms, so that rtc_cmos
can issue system wakeup events (and its sysfs "wakealarm" attribute works on
at least some systems).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a goof in the revised classdev support for RTCs: make sure the /dev
node info is ready before the device is registered, not after. Otherwise
the /sys/class/rtc/rtcN/dev attribute won't be created and then udev won't
have the information it needs to create the /dev/rtcN node.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RTC class suspend/resume support, re-initializing the system clock on resume
from the clock used to initialize it at boot time.
- The reinit-on-resume is hooked to the existing RTC_HCTOSYS config
option, on the grounds that a clock good enough for init must also
be good enough for re-init.
- Inlining a version of the code used by ARM, to save and restore the
delta between a selected RTC and the current system wall-clock time.
- Removes calls to that ARM code from AT91, OMAP1, and S3C RTCs. This
means that systems using those RTCs across suspend/resume will likely
want to change their kernel configs to enable RTC_HCTOSYS.
If HCTOSYS isn't using a second RTC (with battery?), this changes the
system's initial date from Jan 1970 to the epoch this hardware uses:
1998 for AT91, 2000 for OMAP1 (assuming no split power mode), etc.
This goes on top of the patch series removing "struct class_device" usage
from the RTC framework. That's all needed for class suspend()/resume().
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This simplifies the RTC procfs support by removing the class_interface that
hooks it into the rtc core. If it's configured, then sysfs support is now
part of the RTC core, and is never a separate module.
It also removes the class_interface hook, now that its last remaining user is
gone. (That API is usable only with a "struct class_device".)
It's another step towards being able to remove "struct class_device".
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This simplifies the RTC sysfs support by removing the class_interface that
hooks it into the rtc core. If it's configured, then sysfs support is now
part of the RTC core, and is never a separate module.
It's another step towards being able to remove "struct class_device".
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes class_device from the programming interface that the RTC
framework exposes to the rest of the kernel. Now an rtc_device is passed,
which is more type-safe and streamlines all the relevant code.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This simplifies the /dev support by removing a superfluous class_device (the
/sys/class/rtc-dev stuff) and the class_interface that hooks it into the rtc
core. Accordingly, if it's configured then /dev support is now part of the
RTC core, and is never a separate module.
It's another step towards being able to remove "struct class_device".
[bunk@stusta.de: drivers/rtc/rtc-dev.c should #include "rtc-core.h"]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement utimensat(2) which is an extension to futimesat(2) in that it
a) supports nano-second resolution for the timestamps
b) allows to selectively ignore the atime/mtime value
c) allows to selectively use the current time for either atime or mtime
d) supports changing the atime/mtime of a symlink itself along the lines
of the BSD lutimes(3) functions
For this change the internally used do_utimes() functions was changed to
accept a timespec time value and an additional flags parameter.
Additionally the sys_utime function was changed to match compat_sys_utime
which already use do_utimes instead of duplicating the work.
Also, the completely missing futimensat() functionality is added. We have
such a function in glibc but we have to resort to using /proc/self/fd/* which
not everybody likes (chroot etc).
Test application (the syscall number will need per-arch editing):
#include <errno.h>
#include <fcntl.h>
#include <time.h>
#include <sys/time.h>
#include <stddef.h>
#include <syscall.h>
#define __NR_utimensat 280
#define UTIME_NOW ((1l << 30) - 1l)
#define UTIME_OMIT ((1l << 30) - 2l)
int
main(void)
{
int status = 0;
int fd = open("ttt", O_RDWR|O_CREAT|O_EXCL, 0666);
if (fd == -1)
error (1, errno, "failed to create test file \"ttt\"");
struct stat64 st1;
if (fstat64 (fd, &st1) != 0)
error (1, errno, "fstat failed");
struct timespec t[2];
t[0].tv_sec = 0;
t[0].tv_nsec = 0;
t[1].tv_sec = 0;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
struct stat64 st2;
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0)
{
puts ("atim not reset to zero");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim not reset to zero");
status = 1;
}
if (status != 0)
goto out;
t[0] = st1.st_atim;
t[1].tv_sec = 0;
t[1].tv_nsec = UTIME_OMIT;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != st1.st_atim.tv_sec
|| st2.st_atim.tv_nsec != st1.st_atim.tv_nsec)
{
puts ("atim not set");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim changed from zero");
status = 1;
}
if (status != 0)
goto out;
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_OMIT;
t[1] = st1.st_mtim;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != st1.st_atim.tv_sec
|| st2.st_atim.tv_nsec != st1.st_atim.tv_nsec)
{
puts ("mtim changed from original time");
status = 1;
}
if (st2.st_mtim.tv_sec != st1.st_mtim.tv_sec
|| st2.st_mtim.tv_nsec != st1.st_mtim.tv_nsec)
{
puts ("mtim not set");
status = 1;
}
if (status != 0)
goto out;
sleep (2);
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_NOW;
t[1].tv_sec = 0;
t[1].tv_nsec = UTIME_NOW;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
struct timeval tv;
gettimeofday(&tv,NULL);
if (st2.st_atim.tv_sec <= st1.st_atim.tv_sec
|| st2.st_atim.tv_sec > tv.tv_sec)
{
puts ("atim not set to NOW");
status = 1;
}
if (st2.st_mtim.tv_sec <= st1.st_mtim.tv_sec
|| st2.st_mtim.tv_sec > tv.tv_sec)
{
puts ("mtim not set to NOW");
status = 1;
}
if (symlink ("ttt", "tttsym") != 0)
error (1, errno, "cannot create symlink");
t[0].tv_sec = 0;
t[0].tv_nsec = 0;
t[1].tv_sec = 0;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, AT_FDCWD, "tttsym", t, AT_SYMLINK_NOFOLLOW) != 0)
error (1, errno, "utimensat failed");
if (lstat64 ("tttsym", &st2) != 0)
error (1, errno, "lstat failed");
if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0)
{
puts ("symlink atim not reset to zero");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("symlink mtim not reset to zero");
status = 1;
}
if (status != 0)
goto out;
t[0].tv_sec = 1;
t[0].tv_nsec = 0;
t[1].tv_sec = 1;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, fd, NULL, t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != 1 || st2.st_atim.tv_nsec != 0)
{
puts ("atim not reset to one");
status = 1;
}
if (st2.st_mtim.tv_sec != 1 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim not reset to one");
status = 1;
}
if (status == 0)
puts ("all OK");
out:
close (fd);
unlink ("ttt");
unlink ("tttsym");
return status;
}
[akpm@linux-foundation.org: add missing i386 syscall table entry]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The for loop in rcutorture_init uses the condition
cur_ops = torture_ops[i], cur_ops
but then makes the same assignment to cur_ops inside the loop. Remove the
redundant assignment inside the loop, and remove now-unnecessary braces.
Signed-off-by: Josh Triplett <josh@kernel.org>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use ARRAY_SIZE macro already defined in kernel.h
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Align the per cpu runqueue to the cacheline boundary. This will minimize
the number of cachelines touched during remote wakeup.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Ravikiran G Thirumalai <kiran@scalex86.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Make TASK_PREEMPTS_CURR(task, rq) return "true" only if the task's prio
is higher than the current's one and the task is in the "active" array.
This ensures we don't make redundant resched_task() calls when the task
is in the "expired" array (as may happen now in set_user_prio(),
rt_mutex_setprio() and pull_task() ) ;
- generalise conditions for a call to resched_task() in set_user_nice(),
rt_mutex_setprio() and sched_setscheduler()
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: Con Kolivas <kernel@kolivas.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a logical cpu 'x' already has more than one process running, then most
likely the siblings of that cpu 'x' must be busy. Otherwise the idle
siblings would have likely(in most of the scenarios) picked up the extra
load making the load on 'x' atmost one.
Use this logic to eliminate the siblings status check and minimize the cache
misses encountered on a heavily loaded system.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed expensive divides done in try_to_wakeup() and
find_busiest_group() on a bi dual core Opteron machine (total of 4 cores),
moderatly loaded (15.000 context switch per second)
oprofile numbers :
CPU: AMD64 processors, speed 2600.05 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit
mask of 0x00 (No unit mask) count 50000
samples % symbol name
...
613914 1.0498 try_to_wake_up
834 0.0013 :ffffffff80227ae1: div %rcx
77513 0.1191 :ffffffff80227ae4: mov %rax,%r11
608893 1.0413 find_busiest_group
1841 0.0031 :ffffffff802260bf: div %rdi
140109 0.2394 :ffffffff802260c2: test %sil,%sil
Some of these divides can use the reciprocal divides we introduced some
time ago (currently used in slab AFAIK)
We can assume a load will fit in a 32bits number, because with a
SCHED_LOAD_SCALE=128 value, its still a theorical limit of 33554432
When/if we reach this limit one day, probably cpus will have a fast
hardware divide and we can zap the reciprocal divide trick.
Ingo suggested to rename cpu_power to __cpu_power to make clear it should
not be modified without changing its reciprocal value too.
I did not convert the divide in cpu_avg_load_per_task(), because tracking
nr_running changes may be not worth it ? We could use a static table of 32
reciprocal values but it would add a conditional branch and table lookup.
[akpm@linux-foundation.org: !SMP build fix]
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the process idle load balancing in the presence of dynticks. cpus for
which ticks are stopped will sleep till the next event wakes it up.
Potentially these sleeps can be for large durations and during which today,
there is no periodic idle load balancing being done.
This patch nominates an owner among the idle cpus, which does the idle load
balancing on behalf of the other idle cpus. And once all the cpus are
completely idle, then we can stop this idle load balancing too. Checks added
in fast path are minimized. Whenever there are busy cpus in the system, there
will be an owner(idle cpu) doing the system wide idle load balancing.
Open items:
1. Intelligent owner selection (like an idle core in a busy package).
2. Merge with rcu's nohz_cpu_mask?
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Periodic load balancing in recent kernels happen in the softirq. In
certain -rt configurations, these softirqs are handled in softirqd context.
And hence the check for idle processor was always returning busy (as
nr_running > 1).
This patch captures the idle information at the tick and passes this info
to softirq context through an element 'idle_at_tick' in rq.
[kernel@kolivas.org: Fix reverse idle at tick logic]
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
