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: Ingo 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=11737http://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: Andreas 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: Ingo Molnar <mingo@elte.hu>
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: Rusty 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: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup
mtrr main.c is too big, seperate mtrr cleanup and mtrr e820 trim
code to another file.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B87C7B.80809@kernel.org>
Signed-off-by: Ingo 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: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B9BA5A.40108@kernel.org>
Signed-off-by: Ingo 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: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B9101E.76E4.0078.0@novell.com>
Signed-off-by: Ingo 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: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B90961.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
move store_ldt outside the CONFIG_PARAVIRT section and
also clean up the code a bit.
Signed-off-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Ingo 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: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: H. 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: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1236701373.3387.4.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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>
Impact: cleanup and code size reduction on 64-bit
This code is only applied to Intel Pentium and AMD K7 32-bit cpus.
Move those checks to intel_init()/amd_init() for 32-bit
so 64-bit will not build this code.
Also change to use cpu_index check to see if we need to emit warning.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B377D2.8030108@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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>
Impact: build fix
The APIC code rewrite in the x86 tree broke the x86/mce branch:
arch/x86/kernel/cpu/mcheck/threshold.c: In function ‘mce_threshold_interrupt’:
arch/x86/kernel/cpu/mcheck/threshold.c:24: error: implicit declaration of function ‘ack_APIC_irq’
Also tidy up the file a bit while at it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: unification
show_cpuinfo_core is identical for 32 and 64 bit and can be unified,
and CONFIG_X86_HT inherently depends on CONFIG_X86_SMP.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
fix this warning:
arch/x86/kernel/cpu/intel_cacheinfo.c:139: warning: ‘k8_nb_id’ defined but not used
arch/x86/kernel/cpu/intel_cacheinfo.c:527: warning: ‘free_cache_attributes’ defined but not used
arch/x86/kernel/cpu/intel_cacheinfo.c:538: warning: ‘detect_cache_attributes’ defined but not used
Unused variables in the !CONFIG_SYSCTL case.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If the TSC is constant and non-stop, also set it reliable.
(We will turn this off in DMI quirks for multi-chassis systems)
The performance number on a 16-way Nehalem system running
32 tasks that context-switch between each other is significant:
sched_clock_stable=0 sched_clock_stable=1
.................... ....................
22.456925 million/sec 24.306972 million/sec [+8.2%]
lmbench's "lat_ctx -s 0 2" goes from 0.63 microseconds to
0.59 microseconds - a 6.7% increase in context-switching
performance.
Perfstat of 1 million pipe context switches between two tasks:
Performance counter stats for './pipe-test-1m':
[before] [after]
............ ............
37621.421089 36436.848378 task clock ticks (msecs)
0 0 CPU migrations (events)
2000274 2000189 context switches (events)
194 193 pagefaults (events)
8433799643 8171016416 CPU cycles (events) -3.21%
8370133368 8180999694 instructions (events) -2.31%
4158565 3895941 cache references (events) -6.74%
44312 46264 cache misses (events)
2349.287976 2279.362465 wall-time (msecs) -3.06%
The speedup comes straight from the reduction in the instruction
count. sched_clock_cpu() got simpler and the whole workload thus
executes faster.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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>
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>
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>
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>
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>
