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3669 commits

Author SHA1 Message Date
Linus Torvalds
ada19a31a9 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: (35 commits)
  [CPUFREQ] Prevent p4-clockmod from auto-binding to the ondemand governor.
  [CPUFREQ] Make cpufreq-nforce2 less obnoxious
  [CPUFREQ] p4-clockmod reports wrong frequency.
  [CPUFREQ] powernow-k8: Use a common exit path.
  [CPUFREQ] Change link order of x86 cpufreq modules
  [CPUFREQ] conservative: remove 10x from def_sampling_rate
  [CPUFREQ] conservative: fixup governor to function more like ondemand logic
  [CPUFREQ] conservative: fix dbs_cpufreq_notifier so freq is not locked
  [CPUFREQ] conservative: amend author's email address
  [CPUFREQ] Use swap() in longhaul.c
  [CPUFREQ] checkpatch cleanups for acpi-cpufreq
  [CPUFREQ] powernow-k8: Only print error message once, not per core.
  [CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictions
  [CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max}
  [CPUFREQ] powernow-k8: Always compile powernow-k8 driver with ACPI support
  [CPUFREQ] Introduce /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_transition_latency
  [CPUFREQ] checkpatch cleanups for powernow-k8
  [CPUFREQ] checkpatch cleanups for ondemand governor.
  [CPUFREQ] checkpatch cleanups for powernow-k7
  [CPUFREQ] checkpatch cleanups for speedstep related drivers.
  ...
2009-03-26 11:04:08 -07:00
Masami Hiramatsu
30390880de prevent boosting kprobes on exception address
Don't boost at the addresses which are listed on exception tables,
because major page fault will occur on those addresses.  In that case,
kprobes can not ensure that when instruction buffer can be freed since
some processes will sleep on the buffer.

kprobes-ia64 already has same check.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17 09:11:48 -07:00
Linus Torvalds
9e8912e04e Fast TSC calibration: calculate proper frequency error bounds
In order for ntpd to correctly synchronize the clocks, the frequency of
the system clock must not be off by more than 500 ppm (or, put another
way, 1:2000), or ntpd will end up giving up on trying to synchronize
properly, and ends up reseting the clock in jumps instead.

The fast TSC PIT calibration sometimes failed this test - it was
assuming that the PIT reads always took about one microsecond each (2us
for the two reads to get a 16-bit timer), and that calibrating TSC to
the PIT over 15ms should thus be sufficient to get much closer than
500ppm (max 2us error on both sides giving 4us over 15ms: a 270 ppm
error value).

However, that assumption does not always hold: apparently some hardware
is either very much slower at reading the PIT registers, or there was
other noise causing at least one machine to get 700+ ppm errors.

So instead of using a fixed 15ms timing loop, this changes the fast PIT
calibration to read the TSC delta over the individual PIT timer reads,
and use the result to calculate the error bars on the PIT read timing
properly.  We then successfully calibrate the TSC only if the maximum
error bars fall below 500ppm.

In the process, we also relax the timing to allow up to 25ms for the
calibration, although it can happen much faster depending on hardware.

Reported-and-tested-by: Jesper Krogh <jesper@krogh.cc>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17 08:13:17 -07:00
Linus Torvalds
a6a80e1d8c Fix potential fast PIT TSC calibration startup glitch
During bootup, when we reprogram the PIT (programmable interval timer)
to start counting down from 0xffff in order to use it for the fast TSC
calibration, we should also make sure to delay a bit afterwards to allow
the PIT hardware to actually start counting with the new value.

That will happens at the next CLK pulse (1.193182 MHz), so the easiest
way to do that is to just wait at least one microsecond after
programming the new PIT counter value.  We do that by just reading the
counter value back once - which will take about 2us on PC hardware.

Reported-and-tested-by: john stultz <johnstul@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17 07:58:26 -07:00
Linus Torvalds
99adcd9d67 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Add p4-clockmod sysfs-ui removal to feature-removal schedule.
  Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."
2009-03-09 13:23:59 -07:00
Dave Jones
129f8ae9b1 Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."
This reverts commit e088e4c9cd.

Removing the sysfs interface for p4-clockmod was flagged as a
regression in bug 12826.

Course of action:
 - Find out the remaining causes of overheating, and fix them
   if possible. ACPI should be doing the right thing automatically.
   If it isn't, we need to fix that.
 - mark p4-clockmod ui as deprecated
 - try again with the removal in six months.

It's not really feasible to printk about the deprecation, because
it needs to happen at all the sysfs entry points, which means adding
a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.

Signed-off-by: Dave Jones <davej@redhat.com>
2009-03-09 15:07:33 -04:00
Markus Metzger
73bf1b62f5 x86, pebs: correct qualifier passed to ds_write_config() from ds_request_pebs()
ds_write_config() can write the BTS as well as the PEBS part of
the DS config. ds_request_pebs() passes the wrong qualifier, which
results in the wrong configuration to be written.

Reported-by: Stephane Eranian <eranian@googlemail.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090305085721.A22550@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 16:13:15 +01:00
Markus Metzger
9ca0791dca x86, bts: remove bad warning
In case a ptraced task is reaped (while the tracer is still attached),
ds_exit_thread() is called before ptrace_exit(). The latter will
release the bts_tracer and remove the thread's ds_ctx.
The former will WARN() if the context is not NULL.

Oleg Nesterov submitted patches that move ptrace_exit() before
exit_thread() and thus reverse the order of the above calls.

Remove the bad warning. I will add it again when Oleg's changes are in.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090305084954.A22000@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 16:13:15 +01:00
Dave Jones
36e8abf3ed [CPUFREQ] Prevent p4-clockmod from auto-binding to the ondemand governor.
The latency of p4-clockmod sucks so hard that scaling on a regular
basis with ondemand is a really bad idea.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-03-05 00:16:26 -05:00
Leann Ogasawara
dd4124a8a0 x86: add Dell XPS710 reboot quirk
Dell XPS710 will hang on reboot.  This is resolved by adding a quirk to
set bios reboot.

Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: "manoj.iyer" <manoj.iyer@canonical.com>
Cc: <stable@kernel.org>
LKML-Reference: <1236196380.3231.89.camel@emiko>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04 20:56:15 +01:00
Daniel Glöckner
ab9e18587f x86, math-emu: fix init_fpu for task != current
Impact: fix math-emu related crash while using GDB/ptrace

init_fpu() calls finit to initialize a task's xstate, while finit always
works on the current task. If we use PTRACE_GETFPREGS on another
process and both processes did not already use floating point, we get
a null pointer exception in finit.

This patch creates a new function finit_task that takes a task_struct
parameter. finit becomes a wrapper that simply calls finit_task with
current. On the plus side this avoids many calls to get_current which
would each resolve to an inline assembler mov instruction.

An empty finit_task has been added to i387.h to avoid linker errors in
case the compiler still emits the call in init_fpu when
CONFIG_MATH_EMULATION is not defined.

The declaration of finit in i387.h has been removed as the remaining
code using this function gets its prototype from fpu_proto.h.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Bill Metzenthen <billm@melbpc.org.au>
LKML-Reference: <E1Lew31-0004il-Fg@mailer.emlix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04 20:33:16 +01:00
Huang Ying
dd39ecf522 x86: EFI: Back efi_ioremap with init_memory_mapping instead of FIX_MAP
Impact: Fix boot failure on EFI system with large runtime memory range

Brian Maly reported that some EFI system with large runtime memory
range can not boot. Because the FIX_MAP used to map runtime memory
range is smaller than run time memory range.

This patch fixes this issue by re-implement efi_ioremap() with
init_memory_mapping().

Reported-and-tested-by: Brian Maly <bmaly@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Brian Maly <bmaly@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236135513.6204.306.camel@yhuang-dev.sh.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04 19:20:16 +01:00
Brian Maly
ff0c087490 x86: fix DMI on EFI
Impact: reactivate DMI quirks on EFI hardware

DMI tables are loaded by EFI, so the dmi calls must happen after
efi_init() and not before.

Currently Apple hardware uses DMI to determine the framebuffer mappings
for efifb. Without DMI working you also have no video on MacBook Pro.

This patch resolves the DMI issue for EFI hardware (DMI is now properly
detected at boot), and additionally efifb now loads on Apple hardware
(i.e. video works).

Signed-off-by: Brian Maly <bmaly@redhat>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: ying.huang@intel.com
LKML-Reference: <49ADEDA3.1030406@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

 arch/x86/kernel/setup.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
2009-03-04 18:55:56 +01:00
Roland McGrath
ccbe495caa x86-64: syscall-audit: fix 32/64 syscall hole
On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with
ljmp, and then use the "syscall" instruction to make a 64-bit system
call.  A 64-bit process make a 32-bit system call with int $0x80.

In both these cases, audit_syscall_entry() will use the wrong system
call number table and the wrong system call argument registers.  This
could be used to circumvent a syscall audit configuration that filters
based on the syscall numbers or argument details.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-02 15:41:30 -08:00
Matthew Garrett
eb3092cee7 [CPUFREQ] Make cpufreq-nforce2 less obnoxious
Not owning an nforce2 is a sign of good taste, not an error.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:32 -05:00
Matthias-Christian Ott
199785eac8 [CPUFREQ] p4-clockmod reports wrong frequency.
http://bugzilla.kernel.org/show_bug.cgi?id=10968

[ Updated for current tree, and fixed compile failure
  when p4-clockmod was built modular -- davej]

From: Matthias-Christian Ott <ott@mirix.org>
Signed-off-by: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:32 -05:00
Dave Jones
0cb8bc2560 [CPUFREQ] powernow-k8: Use a common exit path.
a0abd520fd introduced a slew of
extra kfree/return -ENODEV pairs. This replaces them all
with gotos.

Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:32 -05:00
Matthew Garrett
de3ed81d74 [CPUFREQ] Change link order of x86 cpufreq modules
Change the link order of the cpufreq modules to ensure that they're
probed in the preferred order when statically linked in.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:32 -05:00
Dave Jones
91420220d2 [CPUFREQ] Use swap() in longhaul.c
Remove hand-coded implementation of swap()

Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:31 -05:00
Dave Jones
3a58df35a6 [CPUFREQ] checkpatch cleanups for acpi-cpufreq
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:31 -05:00
Thomas Renninger
79cc56af9f [CPUFREQ] powernow-k8: Only print error message once, not per core.
This is the typical message you get if you plug in a CPU
which is newer than your BIOS. It's annoying seeing this
message for each core.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:31 -05:00
Thomas Renninger
57f4fa6991 [CPUFREQ] powernow-k8: Always compile powernow-k8 driver with ACPI support
powernow-k8 driver should always try to get cpufreq info from ACPI.
Otherwise it will not be able to detect the transition latency correctly
which results in ondemand governor taking a wrong sampling rate which will
then result in sever performance loss.

Let the user not shoot himself in the foot and always compile in ACPI
support for powernow-k8.

This also fixes a wrong message if ACPI_PROCESSOR is compiled as a module and
#ifndef CONFIG_ACPI_PROCESSOR
path is chosen.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:31 -05:00
Dave Jones
0e64a0c982 [CPUFREQ] checkpatch cleanups for powernow-k8
This driver has so many long function names, and deep nested if's
The remaining warnings will need some code restructuring to clean up.

Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:30 -05:00
Dave Jones
b9e7638a30 [CPUFREQ] checkpatch cleanups for powernow-k7
The asm/timer.h warning can be ignored, it's needed for
recalibrate_cpu_khz()

Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:30 -05:00
Dave Jones
bbfebd6655 [CPUFREQ] checkpatch cleanups for speedstep related drivers.
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:30 -05:00
Dave Jones
6072ace436 [CPUFREQ] checkpatch cleanups for sc520
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:29 -05:00
Dave Jones
14a6650f13 [CPUFREQ] checkpatch cleanups for powernow-k6
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:29 -05:00
Dave Jones
48ee923a66 [CPUFREQ] checkpatch cleanups for longrun
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:29 -05:00
Dave Jones
ac617bd0f7 [CPUFREQ] checkpatch cleanups for longhaul
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:29 -05:00
Dave Jones
00f6a235bf [CPUFREQ] checkpatch cleanups for gx-suspmod
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:29 -05:00
Dave Jones
c9b8c87152 [CPUFREQ] checkpatch cleanups for e_powersaver
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:28 -05:00
Dave Jones
04cd1a99dc [CPUFREQ] checkpatch cleanups for elanfreq
The remaining warning about the simple_strtoul conversion
to strict_strtoul seems kind of pointless to me.

Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:28 -05:00
Dave Jones
20174b65d9 [CPUFREQ] nforce2: Use driver prefix, not cpufreq prefix.
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:28 -05:00
Dave Jones
b5c9166662 [CPUFREQ] checkpatch cleanups for cpufreq-nforce2
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:28 -05:00
Dave Jones
fff78ad5ce [CPUFREQ] Stupidly trivial CodingStyle fix
GNU indent complains about this being ambiguous, because it's dumb.
One of my automated tests relies on the output of indent, so this shuts
it up.

Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:28 -05:00
Rafael J. Wysocki
770824bdc4 PM: Split up sysdev_[suspend|resume] from device_power_[down|up]
Move the sysdev_suspend/resume from the callee to the callers, with
no real change in semantics, so that we can rework the disabling of
interrupts during suspend/hibernation.

This is based on an earlier patch from Linus.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-22 10:33:44 -08:00
Linus Torvalds
936577c61d x86: Add IRQF_TIMER to legacy x86 timer interrupt descriptors
Right now nobody cares, but the suspend/resume code will eventually want
to suspend device interrupts without suspending the timer, and will
depend on this flag to know.

The modern x86 timer infrastructure uses the local APIC timers and never
shows up as a device interrupt at all, so it isn't affected and doesn't
need any of this.

Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-22 10:27:49 -08:00
Jiri Slaby
6defa2fe20 x86_64: Fix S3 fail path
As acpi_enter_sleep_state can fail, take this into account in
do_suspend_lowlevel and don't return to the do_suspend_lowlevel's
caller. This would break (currently) fpu status and preempt count.

Technically, this means use `call' instead of `jmp' and `jmp' to
the `resume_point' after the `call' (i.e. if
acpi_enter_sleep_state returns=fails). `resume_point' will handle
the restore of fpu and preempt count gracefully.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-02-21 21:58:18 -05:00
Jiri Slaby
e6bd6760c9 x86_64: acpi/wakeup_64 cleanup
- remove %ds re-set, it's already set in wakeup_long64
- remove double labels and alignment (ENTRY already adds both)
- use meaningful resume point labelname
- skip alignment while jumping from wakeup_long64 to the resume point
- remove .size, .type and unused labels
[v2]
- added ENDPROCs

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-02-21 21:58:18 -05:00
H. Peter Anvin
cc3ca22063 x86, mce: remove incorrect __cpuinit for mce_cpu_features()
Impact: Bug fix on UP

Checkin 6ec68bff3c:
    x86, mce: reinitialize per cpu features on resume

introduced a call to mce_cpu_features() in the resume path, in order
for the MCE machinery to get properly reinitialized after a resume.
However, this function (and its successors) was flagged __cpuinit,
which becomes __init on UP configurations (on SMP suspend/resume
requires CPU hotplug and so this would not be seen.)

Remove the offending __cpuinit annotations for mce_cpu_features() and
its successor functions.

Cc: Andi Kleen <ak@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-02-20 23:40:40 -08:00
Alok N Kataria
48ffc70b67 x86, vmi: TSC going backwards check in vmi clocksource
Impact: fix time warps under vmware

Similar to the check for TSC going backwards in the TSC clocksource,
we also need this check for VMI clocksource.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
2009-02-20 07:53:08 +01:00
Linus Torvalds
bcf8951fc2 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mce: fix ifdef for 64bit thermal apic vector clear on shutdown
  x86, mce: use force_sig_info to kill process in machine check
  x86, mce: reinitialize per cpu features on resume
  x86, rcu: fix strange load average and ksoftirqd behavior
2009-02-19 09:14:35 -08:00
Andi Kleen
07db1c140e x86, mce: fix ifdef for 64bit thermal apic vector clear on shutdown
Impact: Bugfix

The ifdef for the apic clear on shutdown for the 64bit intel thermal
vector was incorrect and never triggered. Fix that.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-02-17 15:24:34 -08:00
Andi Kleen
380851bc6b x86, mce: use force_sig_info to kill process in machine check
Impact: bug fix (with tolerant == 3)

do_exit cannot be called directly from the exception handler because
it can sleep and the exception handler runs on the exception stack.
Use force_sig() instead.

Based on a earlier patch by Ying Huang who debugged the problem.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-02-17 15:24:31 -08:00
Andi Kleen
6ec68bff3c x86, mce: reinitialize per cpu features on resume
Impact: Bug fix

This fixes a long standing bug in the machine check code. On resume the
boot CPU wouldn't get its vendor specific state like thermal handling
reinitialized. This means the boot cpu wouldn't ever get any thermal
events reported again.

Call the respective initialization functions on resume

v2: Remove ancient init because they don't have a resume device anyways.
    Pointed out by Thomas Gleixner.
v3: Now fix the Subject too to reflect v2 change

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-02-17 15:24:28 -08:00
Linus Torvalds
35010334aa Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vm86: fix preemption bug
  x86, olpc: fix model detection without OFW
  x86, hpet: fix for LS21 + HPET = boot hang
  x86: CPA avoid repeated lazy mmu flush
  x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context
  x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption
  x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem
  x86/cpa: make sure cpa is safe to call in lazy mmu mode
  x86, ptrace, mm: fix double-free on race
2009-02-17 14:27:39 -08:00
Paul E. McKenney
bf51935f3e x86, rcu: fix strange load average and ksoftirqd behavior
Damien Wyart reported high ksoftirqd CPU usage (20%) on an
otherwise idle system.

The function-graph trace Damien provided:

>   799.521187 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521371 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521555 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521738 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521934 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522068 |   1)  ksoftir-2324  |               |                rcu_check_callbacks() {
>   799.522208 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522392 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522575 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522759 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522956 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523074 |   1)  ksoftir-2324  |               |                  rcu_check_callbacks() {
>   799.523214 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523397 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523579 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523762 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523960 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524079 |   1)  ksoftir-2324  |               |                  rcu_check_callbacks() {
>   799.524220 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524403 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524587 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524770 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
> [ . . . ]

Shows rcu_check_callbacks() being invoked way too often. It should be called
once per jiffy, and here it is called no less than 22 times in about
3.5 milliseconds, meaning one call every 160 microseconds or so.

Why do we need to call rcu_pending() and rcu_check_callbacks() from the
idle loop of 32-bit x86, especially given that no other architecture does
this?

The following patch removes the call to rcu_pending() and
rcu_check_callbacks() from the x86 32-bit idle loop in order to
reduce the softirq load on idle systems.

Reported-by: Damien Wyart <damien.wyart@free.fr>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-17 22:47:45 +01:00
Rusty Russell
a0abd520fd cpumask: fix powernow-k8: partial revert of 2fdf66b491
Impact: fix powernow-k8 when acpi=off (or other error).

There was a spurious change introduced into powernow-k8 in this patch:
so that we try to "restore" the cpus_allowed we never saved.  We revert
that file.

See lkml "[PATCH] x86/powernow: fix cpus_allowed brokage when
acpi=off" from Yinghai for the bug report.

Cc: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
2009-02-16 17:31:59 +10:30
Thomas Gleixner
be716615fe x86, vm86: fix preemption bug
Commit 3d2a71a596 ("x86, traps: converge
do_debug handlers") changed the preemption disable logic of do_debug()
so vm86_handle_trap() is called with preemption disabled resulting in:

 BUG: sleeping function called from invalid context at include/linux/kernel.h:155
 in_atomic(): 1, irqs_disabled(): 0, pid: 3005, name: dosemu.bin
 Pid: 3005, comm: dosemu.bin Tainted: G        W  2.6.29-rc1 #51
 Call Trace:
  [<c050d669>] copy_to_user+0x33/0x108
  [<c04181f4>] save_v86_state+0x65/0x149
  [<c0418531>] handle_vm86_trap+0x20/0x8f
  [<c064e345>] do_debug+0x15b/0x1a4
  [<c064df1f>] debug_stack_correct+0x27/0x2c
  [<c040365b>] sysenter_do_call+0x12/0x2f
 BUG: scheduling while atomic: dosemu.bin/3005/0x10000001

Restore the original calling convention and reenable preemption before
calling handle_vm86_trap().

Reported-by: Michal Suchanek <hramrach@centrum.cz>
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15 10:46:13 +01:00
Chris Ball
e49590b6dd x86, olpc: fix model detection without OFW
Impact: fix "garbled display, laptop is unusable" bug

Commit e51a1ac2df ("x86, olpc: fix endian
bug in openfirmware workaround") breaks model comparison on OLPC; the value
0xc2 needs to be scaled up by olpc_board().

The pre-patch version was wrong, but accidentally worked anyway
(big-endian 0xc2 is big enough to satisfy all other board revisions,
but little endian 0xc2 is not).

Signed-off-by: Chris Ball <cjb@laptop.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Andres Salomon <dilinger@queued.net>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14 23:05:25 +01:00