The ACPI code currently disables TSC use in any C2 and C3
states. But the AMD Fam10h BKDG documents that the TSC
will never stop in any C states when the CONSTANT_TSC bit is
set. Make this disabling conditional on CONSTANT_TSC
not set on AMD.
I actually think this is true on Intel too for C2 states
on CPUs with p-state invariant TSC, but this needs
further discussions with Len to really confirm :-)
So far it is only enabled on AMD.
Cc: lenb@kernel.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Aviod TLB flush IPIs during C3 states by voluntary leave_mm()
before entering C3.
The performance impact of TLB flush on C3 should not be significant with
respect to C3 wakeup latency. Also, CPUs tend to flush TLB in hardware while in
C3 anyways.
On a 8 logical CPU system, running make -j2, the number of tlbflush IPIs goes
down from 40 per second to ~ 0. Total number of interrupts during the run
of this workload was ~1200 per second, which makes it ~3% savings in wakeups.
There was no measurable performance or power impact however.
[ akpm@linux-foundation.org: symbol export fixes. ]
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Stop using kobject_register for this static kobject, as it's overkill.
This way is much simpler.
Cc: Len Brown <len.brown@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no firmware "subsystem" it's just a directory in /sys that
other portions of the kernel want to hook into. So make it a kobject
not a kset to help alivate anyone who tries to do some odd kset-like
things with this.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't need a kset here, a simple kobject will do just fine, so
dynamically create the kobject and use it.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't need a "default" ktype for a kset. We should set this
explicitly every time for each kset. This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.
This patch is based on a lot of help from Kay Sievers.
Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The "DEBUG" symbol needs to be defined before #including <linux/kernel.h> to
get the pr_debug() working.
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Len Brown <len.brown@intel.com>
Add leading zeros to pr_debug() calls. For example if x=0x0a, the format
"0x%2x" will result the string "0x a", the format "0x%2.2x" will result "0x0a".
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Len Brown <len.brown@intel.com>
This DMI blacklist reduces the console messages
on systems which have a BIOS that invokes OSI(Linux).
As the DMI blacklist already knows about these systems,
the request for DMI info itself is disabled.
Further, if OSI(Linux) has already been determined
to have no beneift, we disable the console message
requesting acpi_osi=Linux test results.
Signed-off-by: Len Brown <len.brown@intel.com>
If BIOS invokes _OSI(Linux), the kernel response
depends on what the ACPI DMI list knows about the system,
and that is reflectd in dmesg:
1) System unknown to DMI:
ACPI: BIOS _OSI(Linux) query ignored
ACPI: DMI System Vendor: LENOVO
ACPI: DMI Product Name: 7661W1P
ACPI: DMI Product Version: ThinkPad T61
ACPI: DMI Board Name: 7661W1P
ACPI: DMI BIOS Vendor: LENOVO
ACPI: DMI BIOS Date: 10/18/2007
ACPI: Please send DMI info above to linux-acpi@vger.kernel.org
ACPI: If "acpi_osi=Linux" works better, please notify linux-acpi@vger.kernel.org
2) System known to DMI, but effect of OSI(Linux) unknown:
ACPI: DMI detected: Lenovo ThinkPad T61
...
ACPI: BIOS _OSI(Linux) query ignored via DMI
ACPI: If "acpi_osi=Linux" works better, please notify linux-acpi@vger.kernel.org
3) System known to DMI, which disables _OSI(Linux):
ACPI: DMI detected: Lenovo ThinkPad T61
...
ACPI: BIOS _OSI(Linux) query ignored via DMI
4) System known to DMI, which enable _OSI(Linux):
ACPI: DMI detected: Lenovo ThinkPad T61
ACPI: Added _OSI(Linux)
...
ACPI: BIOS _OSI(Linux) query honored via DMI
cmdline overrides take precidence over the built-in
default and the DMI prescribed default.
cmdline "acpi_osi=Linux" results in:
ACPI: BIOS _OSI(Linux) query honored via cmdline
Signed-off-by: Len Brown <len.brown@intel.com>
Linux does not want BIOS writers to invoke _OSI(Linux) -
for in the field it causes more Windows incompatibility problems
than it solves.
So when it is seen in the BIOS for an Intel Customer Reference Board,
Linux should ignore its effect by default, and should complain loudly.
Otherwise, the reference BIOS will go unfixed, and the bad BIOS
will spread to the field.
Users of this board can get the old behavior with "acpi_osi=Linux"
As this was the only entry, delete acpi_osl_dmi_table[].
Signed-off-by: Len Brown <len.brown@intel.com>
Andi Kleen
Venki Pallipadi
Kay Sievers
Greg Kroah-Hartman
Len Brown
Márton Németh
Alexey Starikovskiy