As part of going idle, we already look at the time of the next timer event to determine
which C-state to select etc.
This patch adds functionality that causes the timers that are past their
soft expire time, to fire at this time, before we calculate the next wakeup
time. This functionality will thus avoid wakeups by running timers before
going idle rather than specially waking up for it.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
This patch makes the futex() system call use the per process
slack value; with this users are able to externally control existing
applications to reduce the wakeup rate.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
This patch makes the nanosleep() system call use the per process
slack value; with this users are able to externally control existing
applications to reduce the wakeup rate.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
the slack estimator used unsigned math; however for very short delay it's
possible that by the time you calculate the timeout, it's already passed and
you get a negative time/slack... in an unsigned variable... which then gets
turned into a 100 msec delay rather than zero.
This patch fixes this by using a signed typee in the right places.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
to help debugging and visibility of timer ranges, show them
in the existing timer list in /proc/timer_list
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
this patch adds a _range version of hrtimer_start() so that range timers
can be created; the hrtimer_start() function is just a wrapper around this.
In addition, hrtimer_start_expires() will now preserve existing ranges.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
in some randconfig configurations, hrtimers are used even though
the hrtimer config if off; and it broke the build due to some of
the new functions being on the wrong side of the ifdef.
This patch moves the functions to the other side of the ifdef, fixing
the build bug.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
This patch makes the select() and poll() hrtimers use the new range
feature and settings from the task struct.
In addition, this includes the estimate_accuracy() function that Linus
posted to lkml, but changed entirely based on other peoples lkml feedback.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
We want to be able to control the default "rounding" that is used by
select() and poll() and friends. This is a per process property
(so that we can have a "nice" like program to start certain programs with
a looser or stricter rounding) that can be set/get via a prctl().
For this purpose, a field called "timer_slack_ns" is added to the task
struct. In addition, a field called "default_timer_slack"ns" is added
so that tasks easily can temporarily to a more/less accurate slack and then
back to the default.
The default value of the slack is set to 50 usec; this is significantly less
than 2.6.27's average select() and poll() timing error but still allows
the kernel to group timers somewhat to preserve power behavior. Applications
and admins can override this via the prctl()
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
this patch turns hrtimers into range timers; they have 2 expire points
1) the soft expire point
2) the hard expire point
the kernel will do it's regular best effort attempt to get the timer run
at the hard expire point. However, if some other time fires after the soft
expire point, the kernel now has the freedom to fire this timer at this point,
and thus grouping the events and preventing a power-expensive wakeup in the
future.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
To catch code that still touches the "expires" memory directly, rename it
to have the compiler complain rather than get nasty, hard to explain,
runtime behavior
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts sound/ to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts s390 to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts KVM-ia64 to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts powerpc/oprofile to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts kernel/* to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts sched_cbq to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts timerfd to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts KVM to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
In order to be able to turn hrtimers into range based, we need to provide
accessor functions for getting to the "expires" ktime_t member of the
struct hrtimer.
This patch adds a set of accessors for this purpose:
* hrtimer_set_expires
* hrtimer_set_expires_tv64
* hrtimer_add_expires
* hrtimer_add_expires_ns
* hrtimer_get_expires
* hrtimer_get_expires_tv64
* hrtimer_get_expires_ns
* hrtimer_expires_remaining
* hrtimer_start_expires
No users of these new accessors are added yet; these follow in later patches.
Hopefully this patch can even go into 2.6.27-rc so that the conversions will
not have a bottleneck in -next
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
With lots of help, input and cleanups from Thomas Gleixner
This patch switches select() and poll() over to hrtimers.
The core of the patch is replacing the "s64 timeout" with a
"struct timespec end_time" in all the plumbing.
But most of the diffstat comes from using the just introduced helpers:
poll_select_set_timeout
poll_select_copy_remaining
timespec_add_safe
which make manipulating the timespec easier and less error-prone.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
with hrtimer poll/select, the signal restart data no longer is a single
long representing a jiffies count, but it becomes a second/nanosecond pair
that also needs to encode if there was a timeout at all or not.
This patch adds a struct to the restart_block union for this purpose
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
This patch adds 2 helpers that will be used for the hrtimer based select/poll:
poll_select_set_timeout() is a helper that takes a timeout (as a second, nanosecond
pair) and turns that into a "struct timespec" that represents the absolute end time.
This is a common operation in the many select() and poll() variants and needs various,
common, sanity checks.
poll_select_copy_remaining() is a helper that takes care of copying the remaining
time to userspace, as select(), pselect() and ppoll() do. This function comes in
both a natural and a compat implementation (due to datastructure differences).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
For the select() rework, it's important to be able to add timespec
structures in an overflow-safe manner.
This patch adds a timespec_add_safe() function for this which is similar in
operation to ktime_add_safe(), but works on a struct timespec.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
This patch adds a schedule_hrtimeout() function, to be used by select() and
poll() in a later patch. This function works similar to schedule_timeout()
in most ways, but takes a timespec rather than jiffies.
With a lot of contributions/fixes from Thomas
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
mmc_block_open() increments md->usage although it returns with -EROFS when
default mounting a MMC/SD card with write protect switch on. This
reference counting bug prevents /dev/mmcblkX from being released on card
removal, and situation worsen with reinsertion until the minor number
range runs out.
Reported-by: <sasin@solomon-systech.com>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix some pasto's in comments in the new linux/tracehook.h and
asm-generic/syscall.h files.
Reported-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix regression tracked as http://bugzilla.kernel.org/show_bug.cgi?id=11361
and caused by commit f735a2a1a4 ("[netdrvr]
forcedeth: setup wake-on-lan before shutting down") that makes network
adapters integrated into the NVidia MCP55 chipsets fail to work in kexeced
kernels. The problem appears to be that if the adapter is put into D3_hot
during ->shutdown(), it cannot be brought back into D0 after kexec (ref.
http://marc.info/?l=linux-kernel&m=121900062814967&w=4). Therefore, only
put forcedeth into D3 during ->shutdown() if the system is to be powered
off.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Ayaz Abdulla <aabdulla@nvidia.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I found we can no longer set limit to 0 with 2.6.27-rcX:
# mount -t cgroup -omemory xxx /mnt
# mkdir /mnt/0
# echo 0 > /mnt/0/memory.limit_in_bytes
bash: echo: write error: Device or resource busy
It turned out 'limit' can't be set to 'usage', which is wrong IMO.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: fix process time monotonicity
sched_clock: fix NOHZ interaction
* git://git.infradead.org/~dwmw2/dwmw2-2.6.27:
Revert "[ARM] use the new byteorder headers"
Fix conditional export of kvh.h and a.out.h to userspace.
[MTD] [NAND] tmio_nand: fix base address programming
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (98 commits)
V4L/DVB (8881): gspca: After 'while (retry--) {...}', retry will be -1 but not 0.
V4L/DVB (8880): PATCH: Fix parents on some webcam drivers
V4L/DVB (8877): b2c2 and bt8xx: udelay to mdelay
V4L/DVB (8876): budget: udelay changed to mdelay
V4L/DVB (8874): gspca: Adjust hstart for sn9c103/ov7630 and update usb-id's.
V4L/DVB (8873): gspca: Bad image offset with rev012a of spca561 and adjust exposure.
V4L/DVB (8872): gspca: Bad image format and offset with rev072a of spca561.
V4L/DVB (8870): gspca: Fix dark room problem with sonixb.
V4L/DVB (8869): gspca: Move the Sonix webcams with TAS5110C1B from sn9c102 to gspca.
V4L/DVB (8868): gspca: Support for vga modes with sif sensors in sonixb.
V4L/DVB (8844): dabusb_fpga_download(): fix a memory leak
V4L/DVB (8843): tda10048_firmware_upload(): fix a memory leak
V4L/DVB (8842): vivi_release(): fix use-after-free
V4L/DVB (8840): dib0700: add basic support for Hauppauge Nova-TD-500 (84xxx)
V4L/DVB (8839): dib0700: add comment to identify 35th USB id pair
V4L/DVB (8837): dvb: fix I2C adapters name size
V4L/DVB (8835): gspca: Same pixfmt as the sn9c102 driver and raw Bayer added in sonixb.
V4L/DVB (8834): gspca: Have a bigger buffer for sn9c10x compressed images.
V4L/DVB (8833): gspca: Cleanup the sonixb code.
V4L/DVB (8832): gspca: Bad pixelformat of vc0321 webcams.
...
* 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-2.6:
acer-wmi: remove debugfs entries upon unloading
ACPI: Avoid bogus timeout about SMbus check
fujitsu-laptop: fix regression for P8010 in 2.6.27-rc
ACPI: Make Len Brown the ACPI maintainer again
ACPI: thinkpad-acpi: wan radio control is not experimental
PNPACPI: ignore the producer/consumer bit for extended IRQ descriptors
acpi: add checking for NULL early param
ACPI: Fix typo in "Disable MWAIT via DMI on broken Compal board"
ACPI: Fix now signed module parameter.
ACPI: Change package length error to warning
ACPI: Fix now signed module parameter.
This reverts commit 087d833e5a, which was
reported to break wireless at least in some combinations with 32bit user
space and a 64bit kernel. Alex Williamnson bisected it to this commit.
Reported-and-bisected-by: Alex Williamson <alex.williamson@hp.com>
Acked-by: John W. Linville <linville@tuxdriver.com>
Cc: David Miller <davem@davemloft.net>
Cc: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Spencer reported a problem where utime and stime were going negative despite
the fixes in commit b27f03d4bd. The suspected
reason for the problem is that signal_struct maintains it's own utime and
stime (of exited tasks), these are not updated using the new task_utime()
routine, hence sig->utime can go backwards and cause the same problem
to occur (sig->utime, adds tsk->utime and not task_utime()). This patch
fixes the problem
TODO: using max(task->prev_utime, derived utime) works for now, but a more
generic solution is to implement cputime_max() and use the cputime_gt()
function for comparison.
Reported-by: spencer@bluehost.com
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If HLT stops the TSC, we'll fail to account idle time, thereby inflating the
actual process times. Fix this by re-calibrating the clock against GTOD when
leaving nohz mode.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit ae82cbfc8b. It
needs the new byteorder headers to be exported to userspace, and
they aren't yet -- and probably shouldn't be, at this point in the
2.6.27 release cycle (or ever, for that matter).
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Should clear the next pointer of the TX if we are sure that the
next TX (say NXT) will be submitted to the channel too. Overwise,
we break the chain of descriptors, because we lose the information
about the next descriptor to run. So next time, when invoke
async_tx_run_dependencies() with TX, it's TX->next will be NULL, and
NXT will be never submitted.
Cc: <stable@kernel.org> [2.6.26]
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Some architectures have moved the asm/ into arch/ and some have not.
This patch checks for a.out.h and kvh.h in both places before exporting
the corresponding file from linux/
[dwmw2: simplified a little]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Fix offset of second word used for programming base address of memory
window. Also program tmio with offset of the FCR, not with physical
memory location.
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Ian Molton <spyro@f2s.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch teaches the i2c-sh_mobile driver to make use of wait irqs.
Without this patch only dte irqs are used which may lead to overruns
and cases of missing stop and extra bytes being read on the i2c bus.
Use of wait irqs forces the hardware to pause and wait until the cpu
is ready. Polling is also reworked in this patch to fix ms delay issues.
Verified with bus analyzer and tested on MigoR and AP325RXA boards.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch fixes a problem within the SH implementation of resume_kernel code,
that implements in assembly the bulk of preempt_schedule_irq function without
taking care of the extra code needed to handle the BKL preemptible.
The patch basically consists of removing this asm code and calling the common
C implementation (see kernel/sched.c) as other archs do.
Another change is the missing 'cli' macro invocation at the beginning of
the resume_kernel.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
