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: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len 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: Lin Ming <ming.m.lin@intel.com>
Compile-tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'sched-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits)
sched: Add comments to find_busiest_group() function
sched: Refactor the power savings balance code
sched: Optimize the !power_savings_balance during fbg()
sched: Create a helper function to calculate imbalance
sched: Create helper to calculate small_imbalance in fbg()
sched: Create a helper function to calculate sched_domain stats for fbg()
sched: Define structure to store the sched_domain statistics for fbg()
sched: Create a helper function to calculate sched_group stats for fbg()
sched: Define structure to store the sched_group statistics for fbg()
sched: Fix indentations in find_busiest_group() using gotos
sched: Simple helper functions for find_busiest_group()
sched: remove unused fields from struct rq
sched: jiffies not printed per CPU
sched: small optimisation of can_migrate_task()
sched: fix typos in documentation
sched: add avg_overlap decay
x86, sched_clock(): mark variables read-mostly
sched: optimize ttwu vs group scheduling
sched: TIF_NEED_RESCHED -> need_reshed() cleanup
sched: don't rebalance if attached on NULL domain
...
* '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.
...
Partial revert of commit 129d8bc828
titled 'x86: don't compile vsmp_64 for 32bit'
Commit reverted to compile vsmp_64.c if CONFIG_X86_64 is defined,
since is_vsmp_box() needs to indicate that TSCs are not synchronized, and
hence, not a valid time source, even when CONFIG_X86_VSMP is not defined.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: shai@scalex86.org
LKML-Reference: <20090324061429.GH7278@localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix interrupt emulation code in kretprobe-booster according to
pt_regs update (es/ds change and gs adding).
This issue has been reported on systemtap-bugzilla:
http://sources.redhat.com/bugzilla/show_bug.cgi?id=9965
| On a -tip kernel on x86_32, kretprobe_example (from samples) triggers the
| following backtrace when its retprobing a class of functions that cause a
| copy_from/to_user().
|
| BUG: sleeping function called from invalid context at mm/memory.c:3196
| in_atomic(): 0, irqs_disabled(): 1, pid: 2286, name: cat
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: systemtap-ml <systemtap@sources.redhat.com>
LKML-Reference: <49C7995C.2010601@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: get correct smp_affinity as user requested
The effect of setting desc->affinity (ie. from userspace via sysfs) has
varied over time. In 2.6.27, the 32-bit code anded the value with
cpu_online_map, and both 32 and 64-bit did that anding whenever a cpu
was unplugged.
2.6.29 consolidated this into one routine (and fixed hotplug) but
introduced another variation: anding the affinity with cfg->domain.
We should just set it to what the user said - if possible.
(cpu_mask_to_apicid_and already takes cpu_online_mask into account)
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <49C94DDF.2010703@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix bug with irq-descriptor moving when logical flat
Rusty observed:
> The effect of setting desc->affinity (ie. from userspace via sysfs) has varied
> over time. In 2.6.27, the 32-bit code anded the value with cpu_online_map,
> and both 32 and 64-bit did that anding whenever a cpu was unplugged.
>
> 2.6.29 consolidated this into one routine (and fixed hotplug) but introduced
> another variation: anding the affinity with cfg->domain. Is this right, or
> should we just set it to what the user said? Or as now, indicate that we're
> restricting it.
Eric pointed out that desc->affinity should be what the user requested,
if it is at all possible to honor the user space request.
This bug got introduced by commit 22f65d31b "x86: Update io_apic.c to use
new cpumask API".
Fix it by moving the masking to before the descriptor moving ...
Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
LKML-Reference: <49C94134.4000408@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch move the timestamp from happening in the arch specific
code into the general code. This allows for better control by the tracer
to time manipulation.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This iommu_op can tell if domain have a specific capability, like snooping
control for Intel IOMMU, which can be used by other components of kernel to
adjust the behaviour.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Impact: cleanup
This fixed various signedness issues in setup.c and e820.c:
arch/x86/kernel/setup.c:455:53: warning: incorrect type in argument 3 (different signedness)
arch/x86/kernel/setup.c:455:53: expected int *pnr_map
arch/x86/kernel/setup.c:455:53: got unsigned int extern [toplevel] *<noident>
arch/x86/kernel/setup.c:639:53: warning: incorrect type in argument 3 (different signedness)
arch/x86/kernel/setup.c:639:53: expected int *pnr_map
arch/x86/kernel/setup.c:639:53: got unsigned int extern [toplevel] *<noident>
arch/x86/kernel/setup.c:820:54: warning: incorrect type in argument 3 (different signedness)
arch/x86/kernel/setup.c:820:54: expected int *pnr_map
arch/x86/kernel/setup.c:820:54: got unsigned int extern [toplevel] *<noident>
arch/x86/kernel/e820.c:670:53: warning: incorrect type in argument 3 (different signedness)
arch/x86/kernel/e820.c:670:53: expected int *pnr_map
arch/x86/kernel/e820.c:670:53: got unsigned int [toplevel] *<noident>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
move out msi_ir_chip and ir_ioapic_chip from CONFIG_INTR_REMAP shadow
Fix:
arch/x86/kernel/apic/io_apic.c:1431: warning: ‘msi_ir_chip’ defined but not used
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Impact: cleanup
This patch fixes the following sparse warnings:
arch/x86/kernel/apic/io_apic.c:3602:17: warning: symbol 'hpet_msi_type'
was not declared. Should it be static?
arch/x86/kernel/apic/io_apic.c:3467:30: warning: Using plain integer as
NULL pointer
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.com>
LKML-Reference: <1237741871-5827-2-git-send-email-dmitri.vorobiev@movial.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
To reduce the size of the oversized function __get_smp_config()
There should be no impact to functionality.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Impact: fix incorrect error message
- IO APIC resource allocation error message contains one too many "be".
- Print the error message iff there are IO APICs in the system.
I've seen this error message for some time on my x86-32 laptop...
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Alan Bartlett <ajb.stxsl@googlemail.com>
LKML-Reference: <200903202100.30789.bzolnier@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Check alternate signal stack overflow with proper stack pointer.
The stack pointer of the next signal frame is different if that
task has i387 state.
On x86_64, redzone would be included.
No need to check SA_ONSTACK if we're already using alternate signal stack.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <49C2874D.3080002@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the new API pci_enable_msi_block() to allow drivers to
request multiple MSI and reimplement pci_enable_msi in terms of
pci_enable_msi_block. Ensure that the architecture back ends don't
have to know about multiple MSI.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch changes a VIA PCI quirk to use dev_info() rather than printk().
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgek.org>
When I review the sensitive code ftrace_nmi_enter(), I found
the atomic variable nmi_running does protect NMI VS do_ftrace_mod_code(),
but it can not protects NMI(entered nmi) VS NMI(ftrace_nmi_enter()).
cpu#1 | cpu#2 | cpu#3
ftrace_nmi_enter() | do_ftrace_mod_code() |
not modify | |
------------------------|-----------------------|--
executing | set mod_code_write = 1|
executing --|-----------------------|--------------------
executing | | ftrace_nmi_enter()
executing | | do modify
------------------------|-----------------------|-----------------
ftrace_nmi_exit() | |
cpu#3 may be being modified the code which is still being executed on cpu#1,
it will have undefined results and possibly take a GPF, this patch
prevents it occurred.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <49C0B411.30003@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: cleanup
Refactor the MP-table parsing code via the introduction of the
following helper functions:
skip_entry()
smp_reserve_bootmem()
check_irq_src()
check_slot()
To simplify the code flow and to reduce the size of the
following oversized functions: smp_read_mpc(), smp_scan_config().
There should be no impact to functionality.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, avoid cpumask games
The APM code wants to run on CPU 0: we create an "on_cpu0" wrapper
which uses work_on_cpu() if we're not already on cpu 0.
This introduces a new failure mode: -ENOMEM, so we add an explicit
err arg and handle Linux-style errnos in apm_err().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
LKML-Reference: <200903111631.29787.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
