Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Fix for a regression that was introduced by earlier commit
18b2646f on Mon Apr 6 11:26:08 2009

Regression resulted in the below error happened on systems with
software coordination where per_cpu acpi data will not be initiated for
secondary CPUs in a P-state domain.

On Tue, 2009-04-14 at 23:01 -0700, Zhang, Yanmin wrote:
 My machine hanged with kernel 2.6.30-rc2 when script read
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor.
>
> opps happens in get_measured_perf:
>
>         cur.aperf.whole = readin.aperf.whole -
>                                 per_cpu(drv_data, cpu)->saved_aperf;
>
> Because per_cpu(drv_data, cpu)=NULL.
>
> So function get_measured_perf should check if (per_cpu(drv_data,
> cpu)==NULL)
> and return 0 if it's NULL.

--------------sys log------------------

BUG: unable to handle kernel NULL pointer dereference at
0000000000000020
IP: [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
PGD a7dd88067 PUD a7ccf5067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
CPU 0
Modules linked in: video output
Pid: 2091, comm: kondemand/0 Not tainted 2.6.30-rc2 #1 MP Server
RIP: 0010:[<ffffffff8021af75>]  [<ffffffff8021af75>]
get_measured_perf+0x4a/0xf9
RSP: 0018:ffff880a7d56de20  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000046241a42b6 RCX: ffff88004d219000
RDX: 000000000000b660 RSI: 0000000000000020 RDI: 0000000000000001
RBP: ffff880a7f052000 R08: 00000046241a42b6 R09: ffffffff807639f0
R10: 00000000ffffffea R11: ffffffff802207f4 R12: ffff880a7f052000
R13: ffff88004d20e460 R14: 0000000000ddd5a6 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88004d200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000020 CR3: 0000000a7f1bf000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kondemand/0 (pid: 2091, threadinfo ffff880a7d56c000, task
ffff880a7d4d18c0)
Stack:
 ffff880a7f052078 ffffffff803efd54 00000046241a42b6 000000462ffa9e95
 0000000000000001 0000000000000001 00000000ffffffea ffffffff8064f41a
 0000000000000012 0000000000000012 ffff880a7f052000 ffffffff80650547
Call Trace:
 [<ffffffff803efd54>] ? kobject_get+0x12/0x17
 [<ffffffff8064f41a>] ? __cpufreq_driver_getavg+0x42/0x57
 [<ffffffff80650547>] ? do_dbs_timer+0x147/0x272
 [<ffffffff80650400>] ? do_dbs_timer+0x0/0x272
 [<ffffffff802474ca>] ? worker_thread+0x15b/0x1f5
 [<ffffffff8024a02c>] ? autoremove_wake_function+0x0/0x2e
 [<ffffffff8024736f>] ? worker_thread+0x0/0x1f5
 [<ffffffff80249f0d>] ? kthread+0x54/0x83
 [<ffffffff8020c87a>] ? child_rip+0xa/0x20
 [<ffffffff80249eb9>] ? kthread+0x0/0x83
 [<ffffffff8020c870>] ? child_rip+0x0/0x20
Code: 99 a6 03 00 31 c9 85 c0 0f 85 c3 00 00 00 89 df 4c 8b 44 24 10 48
c7 c2 60 b6 00 00 48 8b 0c fd e0 30 a5 80 4c 89 c3 48 8b 04 0a <48> 2b
58 20 48 8b 44 24 18 48 89 1c 24 48 8b 34 0a 48 2b 46 28
RIP  [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
 RSP <ffff880a7d56de20>
CR2: 0000000000000020
---[ end trace 2b8fac9a49e19ad4 ]---
Tested-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

It turns out that 'smp_call_function_many()' doesn't work at all like
'smp_call_function_single()', and my change to Andrew's patch to use it
rather than a loop over all CPU's acpi-cpufreq doesn't work.

My bad.

'smp_call_function_many()' has two "features" (aka "documented bugs"):

 (a) it needs to be called with preemption disabled, because it uses
     smp_processor_id() without guarding the CPU lookup with 'get_cpu()'
     and 'put_cpu()' like the 'single' variant does.

 (b) even if the current CPU is part of the CPU mask, it won't do the
     call on that CPU.

Still, we're better off trying to use 'smp_call_function_many()' than
looping over CPU's, since it at least in theory allows us to use a
broadcast IPI and do it all in parallel.  So let's just work around the
silly semantic bugs in that function.
Reported-and-tested-by: NAli Gholami Rudi <ali@rudi.ir>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We ended up incorrectly using '&cur' instead of '&readin' in the
work_on_cpu() -> smp_call_function_single() transformation in commit
01599fca ("cpufreq: use
smp_call_function_[single|many]() in acpi-cpufreq.c").

Andrew explains:
 "OK, the acpi tree went and had conflicting changes merged into it after
  I'd written the patch and it appears that I incorrectly reverted part
  of 18b2646f while fixing the resulting
  rejects.

  Switching it to `readin' looks correct."
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Atttempting to rid us of the problematic work_on_cpu().  Just use
smp_call_fuction_single() here.

This repairs a 10% sysbench(oltp)+mysql regression which Mike reported,
due to

  commit 6b44003e
  Author: Andrew Morton <akpm@linux-foundation.org>
  Date:   Thu Apr 9 09:50:37 2009 -0600

      work_on_cpu(): rewrite it to create a kernel thread on demand

It seems that the kernel calls these acpi-cpufreq functions at a quite
high frequency.

Valdis Kletnieks also reports that this causes 70-90 forks per second on
his hardware.

Cc: Valdis.Kletnieks@vt.edu
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Acked-by: NDave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: NMike Galbraith <efault@gmx.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
[ Made it use smp_call_function_many() instead of looping over cpu's
  with smp_call_function_single()    - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It seems by mistake these files got execute permissions so removing it.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1239211186.9037.2.camel@ht.satnam>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add support for Always Running APIC timer, CPUID_0x6_EAX_Bit2.
This bit means the APIC timer continues to run even when CPU is
in deep C-states.

The advantage is that we can use LAPIC timer on these CPUs
always, and there is no need for "slow to read and program"
external timers (HPET/PIT) and the timer broadcast logic
and related code in C-state entry and exit.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Do not write zeroes to APERF and MPERF by ondemand governor. With this
change, other users can share these MSRs for reads.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Change structure name to make the code cleaner and simpler. No
functionality change in this patch.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Remove dupilicated #include in arch/x86/kernel/cpu/cpufreq/longhaul.c.
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The MTRR code grew a new debug message which triggers commonly:

[   40.142276]   get_mtrr: cpu0 reg00 base=0000000000 size=0000080000 write-back
[   40.142280]   get_mtrr: cpu0 reg01 base=0000080000 size=0000040000 write-back
[   40.142284]   get_mtrr: cpu0 reg02 base=0000100000 size=0000040000 write-back
[   40.142311]   get_mtrr: cpu0 reg00 base=0000000000 size=0000080000 write-back
[   40.142314]   get_mtrr: cpu0 reg01 base=0000080000 size=0000040000 write-back
[   40.142317]   get_mtrr: cpu0 reg02 base=0000100000 size=0000040000 write-back

Remove this annoyance.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>

Some BIOSes report very high frequency transition latency which are plainly
wrong on CPus that can change frequency using native MSR interface.

One such system is IBM T42 (2327-8ZU) as reported by Owen Taylor and
Rik van Riel.

cpufreq_ondemand driver uses this transition latency to come up with a
reasonable sampling interval to sample CPU usage and with such high
latency value, ondemand sampling interval ends up being very high
(0.5 sec, in this particular case), resulting in performance impact due to
slow response to increasing frequency.

Fix it by capping-off the transition latency to 20uS for native MSR based
frequency transitions.

mjg: We've confirmed that this also helps on the X31
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

> arch/x86/kernel/cpu/cpufreq/longhaul.c: In function 'longhaul_setstate':
> arch/x86/kernel/cpu/cpufreq/longhaul.c:308: error: implicit declaration of function 'acpi_set_register'
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Compile-tested-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLen Brown <len.brown@intel.com>

Impact: cleanup

 - Fix various style issues
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>

arch/x86/kernel/cpu/mtrr/cleanup.c:197: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1237378015.13488.1.camel@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Fix cpu offline when CONFIG_MAXSMP=y

Changeset bc9b83dd "cpumask: convert
c1e_mask in arch/x86/kernel/process.c to cpumask_var_t" contained a
bug: c1e_mask is manipulated even if C1E isn't detected (and hence
not allocated).

This is simply fixed by checking for NULL (which gcc optimizes out
anyway of CONFIG_CPUMASK_OFFSTACK=n, since it knows ce1_mask can never
be NULL).

In addition, fix a leak where select_idle_routine re-allocates
(and re-clears) c1e_mask on every cpu init.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Mike Travis <travis@sgi.com>
LKML-Reference: <200903171450.34549.rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Attempting to rid us of the problematic work_on_cpu().  Just use
smp_call_function_single() here.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090318042217.EF3F1DDF39@ozlabs.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: don't trim e820 according to wrong mtrr

Ozan reports that his server emits strange warning.
it turns out the BIOS sets the MTRRs incorrectly.

Ignore those strange ranges, and don't trim e820,
just emit one warning about BIOS
Reported-by: NOzan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BEE1E7.7020706@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Bug fix on UP

Referring commit cc3ca220,
Peter removed __cpuinit annotations for mce_cpu_features()
and its successor functions, which caused troubles on UP
configurations.

However the intel_init_cmci() was introduced after that and
it also has __cpuinit annotation even though it is called from
mce_cpu_features(). Remove the annotation from that function
too.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Added AMD CPUs support

Added flags for various AMD CPUs.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

there should be no difference, except:

 * the 64bit variant now also initializes the padlock unit.
 * ->c_early_init() is executed again from ->c_init()
 * the 64bit fixups made into 32bit path.
Signed-off-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: herbert@gondor.apana.org.au
LKML-Reference: <1237029843-28076-2-git-send-email-sebastian@breakpoint.cc>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: print out fewer lines

 1. print continuous range with same type together
 2. change _INFO to _DEBUG
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BACB61.8000302@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix debug warning

Jaswinder noticed that there is a warning about smp_processor_id()
in get_mtrr().

Fix it by wrapping the printout into a get/put_cpu() pair.
Reported-by: NJaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <49BAB7FF.4030107@kernel.org>
[ changed to get/put_cpu(), cleaned up surrounding code a it. ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Complete/fix the cleanups of cpu/common.c:

 - fix ugly warning due to asm/topology.h -> linux/topology.h change
 - standardize the style across the file
 - simplify/refactor the code flow where possible

Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
LKML-Reference: <1237009789.4387.2.camel@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

- fix various style problems
 - declare varibles before they get used
 - introduced clear_all_debug_regs
 - fix header files issues

LKML-Reference: <1237009789.4387.2.camel@localhost.localdomain>
Signed-off-by: NJaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: bug fix + BIOS workaround

BIOS is expected to clear the SYSCFG[MtrrFixDramModEn] on AMD CPUs
after fixed MTRRs are configured.

Some BIOSes do not clear SYSCFG[MtrrFixDramModEn] on BP (and on APs).

This can lead to obfuscation in Linux when this bit is not cleared on
BP but cleared on APs. A consequence of this is that the saved
fixed-MTRR state (from BP) differs from the fixed-MTRRs of APs --
because RdDram/WrDram bits are read as zero when
SYSCFG[MtrrFixDramModEn] is cleared -- and Linux tries to sync
fixed-MTRR state from BP to AP. This implies that Linux sets
SYSCFG[MtrrFixDramEn] and activates those bits.

More important is that (some) systems change these bits in SMM when
ACPI is enabled. Hence it is racy if Linux modifies RdMem/WrMem bits,
too.

(1) The patch modifies an old fix from Bernhard Kaindl to get
    suspend/resume working on some Acer Laptops. Bernhard's patch
    tried to sync RdMem/WrMem bits of fixed MTRR registers and that
    helped on those old Laptops. (Don't ask me why -- can't test it
    myself). But this old problem was not the motivation for the
    patch. (See http://lkml.org/lkml/2007/4/3/110)

(2) The more important effect is to fix issues on some more current systems.

    On those systems Linux panics or just freezes, see

    http://bugzilla.kernel.org/show_bug.cgi?id=11541
    (and also duplicates of this bug:
    http://bugzilla.kernel.org/show_bug.cgi?id=11737
    http://bugzilla.kernel.org/show_bug.cgi?id=11714)

    The affected systems boot only using acpi=ht, acpi=off or
    when the kernel is built with CONFIG_MTRR=n.

    The acpi options prevent full enablement of ACPI.  Obviously when
    ACPI is enabled the BIOS/SMM modfies RdMem/WrMem bits.  When
    CONFIG_MTRR=y Linux also accesses and modifies those bits when it
    needs to sync fixed-MTRRs across cores (Bernhard's fix, see (1)).
    How do you synchronize that? You can't. As a consequence Linux
    shouldn't touch those bits at all (Rationale are AMD's BKDGs which
    recommend to clear the bit that makes RdMem/WrMem accessible).
    This is the purpose of this patch. And (so far) this suffices to
    fix (1) and (2).

I suggest not to touch RdDram/WrDram bits of fixed-MTRRs and
SYSCFG[MtrrFixDramEn] and to clear SYSCFG[MtrrFixDramModEn] as
suggested by AMD K8, and AMD family 10h/11h BKDGs.
BIOS is expected to do this anyway. This should avoid that
Linux and SMM tread on each other's toes ...
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: trenn@suse.de
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090312163937.GH20716@alberich.amd.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

1) &cpu_online_map -> cpu_online_mask
2) first_cpu/next_cpu_nr -> cpumask_first/cpumask_next
3) cpu_*_map manipulation -> init_cpu_* / set_cpu_*
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: cleanup
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: reduce kernel memory usage when CONFIG_CPUMASK_OFFSTACK=y

Simple conversion of mce_device_initialized to cpumask_var_t.  We don't
check the alloc_cpumask_var() return since it's boot-time only, and
the misc_register() in that same function isn't checked.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: reduce per-cpu size for CONFIG_CPUMASK_OFFSTACK=y

In most places it's cleaner to use the accessors cpu_sibling_mask()
and cpu_core_mask() wrappers which already exist.

I couldn't avoid cleaning up the access in oprofile, either.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Supported write flag for registers.
currently write is enabled only for PMC MSR.

[root@ht]# cat /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
0x0

[root@ht]# echo 1234 > /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
[root@ht]# cat /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
0x4d2

[root@ht]# echo 0x1234 > /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
[root@ht]# cat /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
0x1234
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

mtrr main.c is too big, seperate mtrr cleanup and mtrr e820 trim
code to another file.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B87C7B.80809@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: print more debug info

Keep it consistent with autodetect version.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B87C0A.4010105@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: improve MTRR debugging messages

There's still inefficiencies suspected with the MTRR sanitizing
code, so make sure we get all the info we need from a dmesg.

- Remove unneeded mtrr_show

 (It will only printout one time by first cpu, so it is no big deal.)

- Also print out directly from get_mtrr, because it doesn't update mtrr_state.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B9BA5A.40108@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: 32/64-bit consolidation

In a first step, this allows fixing phys_addr_valid() for PAE (which
until now reported all addresses to be valid). Subsequently, this will
also allow simplifying some MTRR handling code.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
LKML-Reference: <49B9101E.76E4.0078.0@novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: debuggability and micro-optimization

Putting whatever is possible into the (final) .rodata section increases
the likelihood of catching memory corruption bugs early, and reduces
false cache line sharing.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
LKML-Reference: <49B90961.76E4.0078.0@novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

move store_ldt outside the CONFIG_PARAVIRT section and
also clean up the code a bit.
Signed-off-by: NJaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: saving power _very_ little

round_jiffies() round up absolute jiffies to full second.
round_jiffies_relative() round up relative jiffies to full second.

The "t->expires" is absolute jiffies. Then, round_jiffies() should be
used instead round_jiffies_relative().
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Introduce:

 cat /sys/kernel/debug/x86/cpu/*

for Intel and AMD processors to view / debug the state of each CPU.

By using this we can debug whole range of registers and other
cpu information for debugging purpose and monitor how things
are changing.

This can be useful for developers as well as for users.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1236701373.3387.4.camel@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>