The x86_64 kernel pushes the fake kernel stack in
arch/x86/kernel/entry_64.S:FAKE_STACK_FRAME, and
rflags register in it does not conform to the specification.
Although Intel's manual[1] says bit 1 of it shall be set to 1,
this bit is cleared to 0 on pushing the fake stack.
[1] Intel(R) 64 and IA-32 Architectures Software Developer's Manual
Vol.1 3-21 Figure 3-8. EFLAGS Register
If it is not on purpose, it is better to be fixed, because
it can lead some tools misunderstanding the stack frame. For example,
"crash" utility[2] actually detects it and warns you like
below:
RIP: ffffffff8005dfa2 RSP: ffff8104ce0c7f58 RFLAGS: 00000200
[...]
bt: WARNING: possibly bogus exception frame
Signed-off-by: Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com>
Tested-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The idea behind commit d91ee5863b ("cpuidle: replace xen access to x86
pm_idle and default_idle") was to have one call - disable_cpuidle()
which would make pm_idle not be molested by other code. It disallows
cpuidle_idle_call to be set to pm_idle (which is excellent).
But in the select_idle_routine() and idle_setup(), the pm_idle can still
be set to either: amd_e400_idle, mwait_idle or default_idle. This
depends on some CPU flags (MWAIT) and in AMD case on the type of CPU.
In case of mwait_idle we can hit some instances where the hypervisor
(Amazon EC2 specifically) sets the MWAIT and we get:
Brought up 2 CPUs
invalid opcode: 0000 [#1] SMP
Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1
RIP: e030:[<ffffffff81015d1d>] [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
...
Call Trace:
[<ffffffff8100e2ed>] cpu_idle+0xae/0xe8
[<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10
RIP [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
RSP <ffff8801d28ddf10>
In the case of amd_e400_idle we don't get so spectacular crashes, but we
do end up making an MSR which is trapped in the hypervisor, and then
follow it up with a yield hypercall. Meaning we end up going to
hypervisor twice instead of just once.
The previous behavior before v3.0 was that pm_idle was set to
default_idle regardless of select_idle_routine/idle_setup.
We want to do that, but only for one specific case: Xen. This patch
does that.
Fixes RH BZ #739499 and Ubuntu #881076
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ Also from Ben Hutchings <ben@decadent.org.uk> and Vitaliy Ivanov
<vitalivanov@gmail.com> ]
Commit 06ae40ce07 ("x86 idle: EXPORT_SYMBOL(default_idle, pm_idle)
only when APM demands it") removed the export for pm_idle/default_idle
unless the apm module was modularised and CONFIG_APM_CPU_IDLE was set.
But the apm module uses pm_idle/default_idle unconditionally,
CONFIG_APM_CPU_IDLE only affects the bios idle threshold. Adjust the
export accordingly.
[ Used #ifdef instead of #if defined() as it's shorter, and what both
Ben and Vitaliy used.. Andy, you're out-voted ;) - Linus ]
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix mwait_play_dead() faulting on mwait-incapable cpus
x86 idle: Fix mwait deprecation warning message
Evil merge to remove extra quote noticed by Joe Perches
* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param
x86 idle: deprecate "no-hlt" cmdline param
x86 idle APM: deprecate CONFIG_APM_CPU_IDLE
x86 idle floppy: deprecate disable_hlt()
x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it
x86 idle: clarify AMD erratum 400 workaround
idle governor: Avoid lock acquisition to read pm_qos before entering idle
cpuidle: menu: fixed wrapping timers at 4.294 seconds
mwait_idle() is a C1-only idle loop intended to be more efficient
than HLT on SMP hardware that supports it.
But mwait_idle() has been replaced by the more general
mwait_idle_with_hints(), which handles both C1 and deeper C-states.
ACPI uses only mwait_idle_with_hints(), and never uses mwait_idle().
Deprecate mwait_idle() and the "idle=mwait" cmdline param
to simplify the x86 idle code.
After this change, kernels configured with
(!CONFIG_ACPI=n && !CONFIG_INTEL_IDLE=n) when run on hardware
that support MWAIT will simply use HLT. If MWAIT is desired
on those systems, cpuidle and the cpuidle drivers above
can be used.
cc: x86@kernel.org
cc: stable@kernel.org # .39.x
Signed-off-by: Len Brown <len.brown@intel.com>
In the long run, we don't want default_idle() or (pm_idle)() to
be exported outside of process.c. Start by not exporting them
to modules, unless the APM build demands it.
cc: x86@kernel.org
cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
The workaround for AMD erratum 400 uses the term "c1e" falsely suggesting:
1. Intel C1E is somehow involved
2. All AMD processors with C1E are involved
Use the string "amd_c1e" instead of simply "c1e" to clarify that
this workaround is specific to AMD's version of C1E.
Use the string "e400" to clarify that the workaround is specific
to AMD processors with Erratum 400.
This patch is text-substitution only, with no functional change.
cc: x86@kernel.org
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add this_cpu_has() which determines if the current cpu has a certain
ability using a segment prefix and a bit test operation.
For that we need to add bit operations to x86s percpu.h.
Many uses of cpu_has use a pointer passed to a function to determine
the current flags. That is no longer necessary after this patch.
However, this patch only converts the straightforward cases where
cpu_has is used with this_cpu_ptr. The rest is work for later.
-tj: Rolled up patch to add x86_ prefix and use percpu_read() instead
of percpu_read_stable().
Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Current stack dump code scans entire stack and check each entry
contains a pointer to kernel code. If CONFIG_FRAME_POINTER=y it
could mark whether the pointer is valid or not based on value of
the frame pointer. Invalid entries could be preceded by '?' sign.
However this was not going to happen because scan start point
was always higher than the frame pointer so that they could not
meet.
Commit 9c0729dc80 ("x86: Eliminate bp argument from the stack
tracing routines") delayed bp acquisition point, so the bp was
read in lower frame, thus all of the entries were marked
invalid.
This patch fixes this by reverting above commit while retaining
stack_frame() helper as suggested by Frederic Weisbecker.
End result looks like below:
before:
[ 3.508329] Call Trace:
[ 3.508551] [<ffffffff814f35c9>] ? panic+0x91/0x199
[ 3.508662] [<ffffffff814f3739>] ? printk+0x68/0x6a
[ 3.508770] [<ffffffff81a981b2>] ? mount_block_root+0x257/0x26e
[ 3.508876] [<ffffffff81a9821f>] ? mount_root+0x56/0x5a
[ 3.508975] [<ffffffff81a98393>] ? prepare_namespace+0x170/0x1a9
[ 3.509216] [<ffffffff81a9772b>] ? kernel_init+0x1d2/0x1e2
[ 3.509335] [<ffffffff81003894>] ? kernel_thread_helper+0x4/0x10
[ 3.509442] [<ffffffff814f6880>] ? restore_args+0x0/0x30
[ 3.509542] [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
[ 3.509641] [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10
after:
[ 3.522991] Call Trace:
[ 3.523351] [<ffffffff814f35b9>] panic+0x91/0x199
[ 3.523468] [<ffffffff814f3729>] ? printk+0x68/0x6a
[ 3.523576] [<ffffffff81a981b2>] mount_block_root+0x257/0x26e
[ 3.523681] [<ffffffff81a9821f>] mount_root+0x56/0x5a
[ 3.523780] [<ffffffff81a98393>] prepare_namespace+0x170/0x1a9
[ 3.523885] [<ffffffff81a9772b>] kernel_init+0x1d2/0x1e2
[ 3.523987] [<ffffffff81003894>] kernel_thread_helper+0x4/0x10
[ 3.524228] [<ffffffff814f6880>] ? restore_args+0x0/0x30
[ 3.524345] [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
[ 3.524445] [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10
-v5:
* fix build breakage with oprofile
-v4:
* use 0 instead of regs->bp
* separate out printk changes
-v3:
* apply comment from Frederic
* add a couple of printk fixes
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Soren Sandmann <ssp@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1300416006-3163-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The "Type 2" SMBIOS record that contains Board Name is not
strictly required and may be absent in the SMBIOS on some
platforms.
( Please note that Type 2 is not listed in Table 3 in Sec 6.2
("Required Structures and Data") of the SMBIOS v2.7
Specification. )
Use the Manufacturer Name (aka System Vendor) name.
Print Board Name only when it is present.
Before the fix:
(i) dmesg output: DMI: /ProLiant DL380 G6, BIOS P62 01/29/2011
(ii) oops output: Pid: 2170, comm: bash Not tainted 2.6.38-rc4+ #3 /ProLiant DL380 G6
After the fix:
(i) dmesg output: DMI: HP ProLiant DL380 G6, BIOS P62 01/29/2011
(ii) oops output: Pid: 2278, comm: bash Not tainted 2.6.38-rc4+ #4 HP ProLiant DL380 G6
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Reviewed-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: <stable@kernel.org> # .3x - good for debugging, please apply as far back as it applies cleanly
LKML-Reference: <20110214224423.2182.13929.sendpatchset@nchumbalkar.americas.hpqcorp.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We use it in non __cpuinit code now too so drop marker.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20110211171754.GA21047@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently intel_idle and acpi_idle driver show double cpu_idle "exit idle"
events -> this patch fixes it and makes cpu_idle events throwing less complex.
It also introduces cpu_idle events for all architectures which use
the cpuidle subsystem, namely:
- arch/arm/mach-at91/cpuidle.c
- arch/arm/mach-davinci/cpuidle.c
- arch/arm/mach-kirkwood/cpuidle.c
- arch/arm/mach-omap2/cpuidle34xx.c
- arch/drivers/acpi/processor_idle.c (for all cases, not only mwait)
- arch/x86/kernel/process.c (did throw events before, but was a mess)
- drivers/idle/intel_idle.c (did throw events before)
Convention should be:
Fire cpu_idle events inside the current pm_idle function (not somewhere
down the the callee tree) to keep things easy.
Current possible pm_idle functions in X86:
c1e_idle, poll_idle, cpuidle_idle_call, mwait_idle, default_idle
-> this is really easy is now.
This affects userspace:
The type field of the cpu_idle power event can now direclty get
mapped to:
/sys/devices/system/cpu/cpuX/cpuidle/stateX/{name,desc,usage,time,...}
instead of throwing very CPU/mwait specific values.
This change is not visible for the intel_idle driver.
For the acpi_idle driver it should only be visible if the vendor
misses out C-states in his BIOS.
Another (perf timechart) patch reads out cpuidle info of cpu_idle
events from:
/sys/.../cpuidle/stateX/*, then the cpuidle events are mapped
to the correct C-/cpuidle state again, even if e.g. vendors miss
out C-states in their BIOS and for example only export C1 and C3.
-> everything is fine.
Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: Robert Schoene <robert.schoene@tu-dresden.de>
CC: Jean Pihet <j-pihet@ti.com>
CC: Arjan van de Ven <arjan@linux.intel.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: linux-pm@lists.linux-foundation.org
CC: linux-acpi@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-perf-users@vger.kernel.org
CC: linux-omap@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
Having four variables for the same thing:
idle_halt, idle_nomwait, force_mwait and boot_option_idle_overrides
is rather confusing and unnecessary complex.
if idle= boot param is passed, only set up one variable:
boot_option_idle_overrides
Introduces following functional changes/fixes:
- intel_idle driver does not register if any idle=xy
boot param is passed.
- processor_idle.c will also not register a cpuidle driver
and get active if idle=halt is passed.
Before a cpuidle driver with one (C1, halt) state got registered
Now the default_idle function will be used which finally uses
the same idle call to enter sleep state (safe_halt()), but
without registering a whole cpuidle driver.
That means idle= param will always avoid cpuidle drivers to register
with one exception (same behavior as before):
idle=nomwait
may still register acpi_idle cpuidle driver, but C1 will not use
mwait, but hlt. This can be a workaround for IO based deeper sleep
states where C1 mwait causes problems.
Signed-off-by: Thomas Renninger <trenn@suse.de>
cc: x86@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
Add these new power trace events:
power:cpu_idle
power:cpu_frequency
power:machine_suspend
The old C-state/idle accounting events:
power:power_start
power:power_end
Have now a replacement (but we are still keeping the old
tracepoints for compatibility):
power:cpu_idle
and
power:power_frequency
is replaced with:
power:cpu_frequency
power:machine_suspend is newly introduced.
Jean Pihet has a patch integrated into the generic layer
(kernel/power/suspend.c) which will make use of it.
the type= field got removed from both, it was never
used and the type is differed by the event type itself.
perf timechart userspace tool gets adjusted in a separate patch.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-3-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
Replace all uses of current_cpu_data with this_cpu operations on the
per cpu structure cpu_info. The scala accesses are replaced with the
matching this_cpu ops which results in smaller and more efficient
code.
In the long run, it might be a good idea to remove cpu_data() macro
too and use per_cpu macro directly.
tj: updated description
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The various stack tracing routines take a 'bp' argument in which the
caller is supposed to provide the base pointer to use, or 0 if doesn't
have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not
defined, this means all callers in principle should either always pass
0, or be conditional on CONFIG_FRAME_POINTER.
However, there are only really three use cases for stack tracing:
(a) Trace the current task, including IRQ stack if any
(b) Trace the current task, but skip IRQ stack
(c) Trace some other task
In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just
be 0. If it _is_ defined, then
- in case (a) bp should be gotten directly from the CPU's register, so
the caller should pass NULL for regs,
- in case (b) the caller should should pass the IRQ registers to
dump_trace(),
- in case (c) bp should be gotten from the top of the task's stack, so
the caller should pass NULL for regs.
Hence, the bp argument is not necessary because the combination of
task and regs is sufficient to determine an appropriate value for bp.
This patch introduces a new inline function stack_frame(task, regs)
that computes the desired bp. This function is then called from the
two versions of dump_stack().
Signed-off-by: Soren Sandmann <ssp@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>,
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>,
LKML-Reference: <m3oc9rop28.fsf@dhcp-100-3-82.bos.redhat.com>>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
