The current code incorrectly assumes that
(1) the APEI register bit width is always 8, 16, 32, or 64 and
(2) the APEI register bit width is always equal to the APEI
register access width.
ERST serialization instructions entries such as:
[030h 0048 1] Action : 00 [Begin Write Operation]
[031h 0049 1] Instruction : 03 [Write Register Value]
[032h 0050 1] Flags (decoded below) : 01
Preserve Register Bits : 1
[033h 0051 1] Reserved : 00
[034h 0052 12] Register Region : [Generic Address Structure]
[034h 0052 1] Space ID : 00 [SystemMemory]
[035h 0053 1] Bit Width : 03
[036h 0054 1] Bit Offset : 00
[037h 0055 1] Encoded Access Width : 03 [DWord Access:32]
[038h 0056 8] Address : 000000007F2D7038
[040h 0064 8] Value : 0000000000000001
[048h 0072 8] Mask : 0000000000000007
break this assumption by yielding:
[Firmware Bug]: APEI: Invalid bit width in GAR [0x7f2d7038/3/0]
I have found no ACPI specification requirements corresponding
with the above assumptions. There is even a good example in
the Serialization Instruction Entries section (ACPI 4.0 section
17.4,1.2, ACPI 4.0a section 2.5.1.2, ACPI 5.0 section 18.5.1.2)
that mentions a serialization instruction with a bit range of
[6:2] which is 5 bits wide, _not_ 8, 16, 32, or 64 bits wide.
Compile and boot tested with 3.3.0-rc7 on a IBM HX5.
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add description of parameter notrigger in the einj.txt.
One can utilize this new parameter to do some SRAR injection
test. Pay attention, the operation is highly depended on the
BIOS implementation. If no proper BIOS supports it, even if
enabling this parameter, expected result will not happen.
v2:
Update the documentation suggested by Tony
Suggested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some APEI firmware implementation will access injected address
specified in param1 to trigger the error when injecting memory
error, which means if one SRAR error is injected, the crash
always happens because it is executed in kernel context. This
new parameter can disable trigger action and control is taken
over by the user. In this way, an SRAR error can happen in user
context instead of crashing the system. This function is highly
depended on BIOS implementation so please ensure you know the
BIOS trigger procedure before you enable this switch.
v2:
notrigger should be created together with param1/param2
Tested-by: Tony Luck <tony.luck@lintel.com>
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
On the platforms with ACPI4.x support, parameter extension
is not always doable, which means only parameter extension
is enabled, einj_param can take effect.
v2->v1: stopping early in einj_get_parameter_address for einj_param
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This fixes a trivial copy & paste error in ERST header length check.
It's just for future safety because sizeof(struct acpi_table_einj)
equals to sizeof(struct acpi_table_erst) with current ACPI5.0
specification. It applies to v3.3-rc6.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
power_usage is always assigned a negative value and should be declared
a signed integer
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Currently when a CPU is off-lined it enters either MWAIT-based idle or,
if MWAIT is not desired or supported, HLT-based idle (which places the
processor in C1 state). This patch allows processors without MWAIT
support to stay in states deeper than C1.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull SuperH updates from Paul Mundt.
* tag 'sh-for-linus' of git://github.com/pmundt/linux-sh: (25 commits)
sh: Support I/O space swapping where needed.
sh: use set_current_blocked() and block_sigmask()
sh: no need to reset handler if SA_ONESHOT
sh: intc: Fix up section mismatch for intc_ack_data
sh: select ARCH_DISCARD_MEMBLOCK.
sh: Consolidate duplicate _32/_64 unistd definitions.
sh: ecovec: switch SDHI controllers to card polling
sh: Avoid exporting unimplemented syscalls.
sh: add platform_device for RSPI in setup-sh7757
SH: pci-sh7780: enable big-endian operation.
serial: sh-sci: fix a race of DMA submit_tx on transfer
sh: dma: Collect up CHCR of SH7763, SH7764, SH7780 and SH7785
sh: dma: Collect up CHCR of SH7723 and SH7730
sh/next: Fix build fail by asm/system.h in asm/bitops.h
arch/sh/drivers/dma/{dma-g2,dmabrg}.c: ensure arguments to request_irq and free_irq are compatible
sh: cpufreq: Wire up scaling_available_freqs support.
sh: cpufreq: notify about rate rounding fallback.
sh: cpufreq: Support CPU clock frequency table.
sh: cpufreq: struct device lookup from CPU topology.
sh: cpufreq: percpu struct clk accounting.
...
acpi_processor_install_hotplug_notify() registers processor objects to
receive ACPI CPU hotplug event notifications. This patch additionally
registers processor device objects (ACPI0007) to receive the notifications
as well.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The X86_32-only disable_hlt/enable_hlt mechanism was used by the
32-bit floppy driver. Its effect was to replace the use of the
HLT instruction inside default_idle() with cpu_relax() - essentially
it turned off the use of HLT.
This workaround was commented in the code as:
"disable hlt during certain critical i/o operations"
"This halt magic was a workaround for ancient floppy DMA
wreckage. It should be safe to remove."
H. Peter Anvin additionally adds:
"To the best of my knowledge, no-hlt only existed because of
flaky power distributions on 386/486 systems which were sold to
run DOS. Since DOS did no power management of any kind,
including HLT, the power draw was fairly uniform; when exposed
to the much hhigher noise levels you got when Linux used HLT
caused some of these systems to fail.
They were by far in the minority even back then."
Alan Cox further says:
"Also for the Cyrix 5510 which tended to go castors up if a HLT
occurred during a DMA cycle and on a few other boxes HLT during
DMA tended to go astray.
Do we care ? I doubt it. The 5510 was pretty obscure, the 5520
fixed it, the 5530 is probably the oldest still in any kind of
use."
So, let's finally drop this.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Stephen Hemminger <shemminger@vyatta.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org
[ If anyone cares then alternative instruction patching could be
used to replace HLT with a one-byte NOP instruction. Much simpler. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Print physical address info in a style consistent with the %pR style used
elsewhere in the kernel.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>
An HP laptop (Pavilion G4-1016tx) has the following code in _TMP:
Store (\_SB.PCI0.LPCB.EC0.RTMP, Local0)
If (LGreaterEqual (Local0, S4TP))
{
Store (One, HTS4)
}
S4TP is initialised at 0 and not programmed further until either _HOT or
_CRT is called. If we evaluate _TMP before the trip points then HTS4 will
always be set, causing the firmware to generate a message on boot
complaining that the system shut down because of overheating. The simplest
solution is just to reverse the checking of trip points and _TMP in thermal
init.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
acpi_dev_run_wake() is a generic function which can be used by
other subsystem too. Rename it to acpi_pm_device_run_wake, to be
consistent with acpi_pm_device_sleep_wake.
Then move it to ACPI core.
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
All the modules name are ro-data, it is never copied to the array.
eg.
static struct cpuidle_driver intel_idle_driver = {
.name = "intel_idle",
.owner = THIS_MODULE,
};
It safe to assign the pointer of this ro-data to a const char *.
By this way we save 12 bytes.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Tested-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Len Brown <len.brown@intel.com>
If the state_count is not initialized for the device use
the driver's state count as the default. That will prevent
to add it manually in the cpuidle driver initialization
routine and will save us from duplicate line of code.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Some C states of new CPU might be not good. One reason is BIOS might
configure them incorrectly. To help developers root cause it quickly, the
patch adds a new sysfs entry, so developers could disable specific C state
manually.
In addition, C state might have much impact on performance tuning, as it
takes much time to enter/exit C states, which might delay interrupt
processing. With the new debug option, developers could check if a deep C
state could impact performance and how much impact it could cause.
Also add this option in Documentation/cpuidle/sysfs.txt.
[akpm@linux-foundation.org: check kstrtol return value]
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com>
Reviewed-and-Tested-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Devices may share same list of power resources in _PR0, for example
Device(Dev0)
{
Name (_PR0, Package (0x01)
{
P0PR,
P1PR
})
}
Device(Dev1)
{
Name (_PR0, Package (0x01)
{
P0PR,
P1PR
}
}
Assume Dev0 and Dev1 were runtime suspended.
Then Dev0 is resumed first and it goes into D0 state.
But Dev1 is left in D0_Uninitialised state.
This is wrong. In this case, Dev1 must be resumed too.
In order to hand this case, each power resource maintains a list of
devices which relies on it.
When power resource is ON, it will check if the devices on its list
can be resumed. The device can only be resumed when all the power
resouces of its _PR0 are ON.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
If a device has _PR3, it means the device supports D3_COLD.
Add the ability to validate and enter D3_COLD state in ACPI.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Repair a common problem with objects that are defined to return
a variable-length Package of sub-objects. If there is only one
sub-object, some BIOS code mistakenly simply declares the single
object instead of a Package with one sub-object. This function
attempts to repair this error by wrapping a Package object around
the original object, creating the correct and expected Package
with one sub-object.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some ACPI interrupt actions may need to wait, and it's easiest to
have a thread context for this. So turn the ACPI interrupt
into a threaded interrupt.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
WARN() is not supposed to have side effects, so move the request_regions
outside.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
jump_label.c needs asm/cacheflush.h to get flushi().
kgdb_64.c needs asm/cacheflush.h to get flushw_all().
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes this build error:
kernel/signal.c: In function 'ptrace_stop':
kernel/signal.c:1860:3: error: implicit declaration of function 'synchronize_user_stack' [-Werror=implicit-function-declaration]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull urgent cgroup fix from Tejun Heo:
"Commit 61d1d219c4 ('cgroup: remove extra calls to
find_existing_css_set') which was part of the rc1 cgroup pull request
made writes to the cgroup "tasks" file return an uninitialized retval
on success which can cause boot failures with systemd.
The change stayed in linux-next for quite some time but gcc
interestingly failed to emit warning about using uninitialized
variable and the problem seems to materialize only for certain build
combinations (probably depends on register allocation).
It's just missing local variable initialization and the fix is trivial
& safe. As the problem is critical when it materializes, I'm
fast-tracking it. Also included is Li's email address change in
MAINTAINERS."
* 'for-3.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: cgroup_attach_task() could return -errno after success
cgroup: update MAINTAINERS entry
61d1d219c4 "cgroup: remove extra calls to find_existing_css_set" made
cgroup_task_migrate() return void. An unfortunate side effect was
that cgroup_attach_task() was depending on that function's return
value to clear its @retval on the success path. On cgroup mounts
without any subsystem with ->can_attach() callback,
cgroup_attach_task() ended up returning @retval without initializing
it on success.
For some reason, gcc failed to warn about it and it didn't cause
cgroup_attach_task() to return non-zero value in many cases, probably
due to difference in register allocation. When the problem
materializes, systemd fails to populate /systemd cgroup mount and
fails to boot.
Fix it by initializing @retval to zero on declaration.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jiri Kosina <jkosina@suse.cz>
LKML-Reference: <alpine.LNX.2.00.1203282354440.25526@pobox.suse.cz>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Pull arm-soc fixes from Olof Johansson:
"This is a first pass of some of the merge window fallout for ARM
platforms.
Nothing controversial:
- A system.h fallout fix for OMAP
- PXA fixes for breakage caused by the regulator struct changes
- GPIO fixes for OMAP to properly deal with dynamic IRQ allocation
- A mismerge in our arm-soc tree of an lpc32xx change for networking
- A fix for USB setup on tegra
- An undo of __init annotation of display mux setup on OMAP that's
needed at runtime"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: pxa: fix build issue on stargate2
ARM: pxa: fix build issue on cm-x300
ARM: pxa: fix build failure for regulator consumer in em-x270.c
ARM: LPC32xx: clock.c: Fix lpc-eth clock reference
ARM: OMAP: pm: fix compilation break
ARM: OMAP: Remove OMAP_GPIO_IRQ macro definition
drivers: input: Fix OMAP_GPIO_IRQ with gpio_to_irq() in ams_delta_serio_exit()
ARM: OMAP: boards: Fix OMAP_GPIO_IRQ usage with gpio_to_irq()
ARM: pxa: fix regulator related build fail in magician_defconfig
ARM: tegra: Fix device tree AUXDATA for USB/EHCI
ARM: OMAP2+: Remove __init from DSI mux functions
Sometimes users have turbostat running in interval mode
when they take processors offline/online.
Previously, turbostat would survive, but not gracefully.
Tighten up the error checking so turbostat notices
changesn sooner, and print just 1 line on change:
turbostat: re-initialized with num_cpus %d
Signed-off-by: Len Brown <len.brown@intel.com>
turbostat uses /dev/cpu/*/msr interface to read MSRs.
For modern systems, it reads 10 MSR/CPU. This can
be observed as 10 "Function Call Interrupts"
per CPU per sample added to /proc/interrupts.
This overhead is measurable on large idle systems,
and as Yoquan Song pointed out, it can even trick
cpuidle into thinking the system is busy.
Here turbostat re-schedules itself in-turn to each
CPU so that its MSR reads will always be local.
This replaces the 10 "Function Call Interrupts"
with a single "Rescheduling interrupt" per sample
per CPU.
On an idle 32-CPU system, this shifts some residency from
the shallow c1 state to the deeper c7 state:
# ./turbostat.old -s
%c0 GHz TSC %c1 %c3 %c6 %c7 %pc2 %pc3 %pc6 %pc7
0.27 1.29 2.29 0.95 0.02 0.00 98.77 20.23 0.00 77.41 0.00
0.25 1.24 2.29 0.98 0.02 0.00 98.75 20.34 0.03 77.74 0.00
0.27 1.22 2.29 0.54 0.00 0.00 99.18 20.64 0.00 77.70 0.00
0.26 1.22 2.29 1.22 0.00 0.00 98.52 20.22 0.00 77.74 0.00
0.26 1.38 2.29 0.78 0.02 0.00 98.95 20.51 0.05 77.56 0.00
^C
i# ./turbostat.new -s
%c0 GHz TSC %c1 %c3 %c6 %c7 %pc2 %pc3 %pc6 %pc7
0.27 1.20 2.29 0.24 0.01 0.00 99.49 20.58 0.00 78.20 0.00
0.27 1.22 2.29 0.25 0.00 0.00 99.48 20.79 0.00 77.85 0.00
0.27 1.20 2.29 0.25 0.02 0.00 99.46 20.71 0.03 77.89 0.00
0.28 1.26 2.29 0.25 0.01 0.00 99.46 20.89 0.02 77.67 0.00
0.27 1.20 2.29 0.24 0.01 0.00 99.48 20.65 0.00 78.04 0.00
cc: Youquan Song <youquan.song@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull devicetree documentation update from Grant Likely.
* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux-2.6:
dt: Linux DT usage model documentation
mtd: Move fdt partition documentation to a seperate file
Pull x86 cleanups from Peter Anvin:
"The biggest textual change is the cleanup to use symbolic constants
for x86 trap values.
The only *functional* change and the reason for the x86/x32 dependency
is the move of is_ia32_task() into <asm/thread_info.h> so that it can
be used in other code that needs to understand if a system call comes
from the compat entry point (and therefore uses i386 system call
numbers) or not. One intended user for that is the BPF system call
filter. Moving it out of <asm/compat.h> means we can define it
unconditionally, returning always true on i386."
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Move is_ia32_task to asm/thread_info.h from asm/compat.h
x86: Rename trap_no to trap_nr in thread_struct
x86: Use enum instead of literals for trap values
v2: 2nd draft
- Editorial cleanups (Randy Dunlap and Stephen Warren)
- Added missing Microblaze reference (Stephen Neuendorffer)
- Make example of platform_device creation clearer (Shawn Guo)
- Expand on PowerPC history and mention i2c mess (David Gibson)
- convert to plain text (remove bits of html formating)
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Pull x32 support for x86-64 from Ingo Molnar:
"This tree introduces the X32 binary format and execution mode for x86:
32-bit data space binaries using 64-bit instructions and 64-bit kernel
syscalls.
This allows applications whose working set fits into a 32 bits address
space to make use of 64-bit instructions while using a 32-bit address
space with shorter pointers, more compressed data structures, etc."
Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}
* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
x32: Fix alignment fail in struct compat_siginfo
x32: Fix stupid ia32/x32 inversion in the siginfo format
x32: Add ptrace for x32
x32: Switch to a 64-bit clock_t
x32: Provide separate is_ia32_task() and is_x32_task() predicates
x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
x86/x32: Fix the binutils auto-detect
x32: Warn and disable rather than error if binutils too old
x32: Only clear TIF_X32 flag once
x32: Make sure TS_COMPAT is cleared for x32 tasks
fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
fs: Fix close_on_exec pointer in alloc_fdtable
x32: Drop non-__vdso weak symbols from the x32 VDSO
x32: Fix coding style violations in the x32 VDSO code
x32: Add x32 VDSO support
x32: Allow x32 to be configured
x32: If configured, add x32 system calls to system call tables
x32: Handle process creation
x32: Signal-related system calls
x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h>
...
arch/arm/mach-pxa/stargate2.c:155:3: error: unknown field ‘dev’
specified in initializer
arch/arm/mach-pxa/stargate2.c:155:3: warning: initialization from
incompatible pointer type [enabled by default]
arch/arm/mach-pxa/stargate2.c:155:3: warning: (near initialization for
‘stargate2_sensor_3_con[0].dev_name’) [enabled by default]
make[1]: *** [arch/arm/mach-pxa/stargate2.o] Error 1
make: *** [arch/arm/mach-pxa] Error 2
It's caused by 'dev' field removed from struct
regulator_consumer_supply.
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Pull "ARM: cleanups of io includes" from Olof Johansson:
"Rob Herring has done a sweeping change cleaning up all of the
mach/io.h includes, moving some of the oft-repeated macros to a common
location and removing a bunch of boiler plate. This is another step
closer to a common zImage for multiple platforms."
Fix up various fairly trivial conflicts (<mach/io.h> removal vs changes
around it, tegra localtimer.o is *still* gone, yadda-yadda).
* tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (29 commits)
ARM: tegra: Include assembler.h in sleep.S to fix build break
ARM: pxa: use common IOMEM definition
ARM: dma-mapping: convert ARCH_HAS_DMA_SET_COHERENT_MASK to kconfig symbol
ARM: __io abuse cleanup
ARM: create a common IOMEM definition
ARM: iop13xx: fix missing declaration of iop13xx_init_early
ARM: fix ioremap/iounmap for !CONFIG_MMU
ARM: kill off __mem_pci
ARM: remove bunch of now unused mach/io.h files
ARM: make mach/io.h include optional
ARM: clps711x: remove unneeded include of mach/io.h
ARM: dove: add explicit include of dove.h to addr-map.c
ARM: at91: add explicit include of hardware.h to uncompressor
ARM: ep93xx: clean-up mach/io.h
ARM: tegra: clean-up mach/io.h
ARM: orion5x: clean-up mach/io.h
ARM: davinci: remove unneeded mach/io.h include
[media] davinci: remove includes of mach/io.h
ARM: OMAP: Remove remaining includes for mach/io.h
ARM: msm: clean-up mach/io.h
...
Commit 737f360d5b
"regulator: Remove support for supplies specified by struct device"
caused this file to break, since it was still relying on the
device field to be present. Map it onto dev_name appropriately
Since there are two consumers with the name "reg-userspace-consumer",
we have to supply the ID as a suffix in the REGULATOR_CONSUMER calls.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
CC: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
This reverts commit b43d17f319.
Dave Jones reports that it causes lockups on his laptop, and his debug
output showed a lot of processes hung waiting for page_writeback (or
more commonly - processes hung waiting for a lock that was held during
that writeback wait).
The page_writeback hint made Ted suggest that Dave look at this commit,
and Dave verified that reverting it makes his problems go away.
Ted says:
"That commit fixes a race which is seen when you write into fallocated
(and hence uninitialized) disk blocks under *very* heavy memory
pressure. Furthermore, although theoretically it could trigger under
normal direct I/O writes, it only seems to trigger if you are issuing
a huge number of AIO writes, such that a just-written page can get
evicted from memory, and then read back into memory, before the
workqueue has a chance to update the extent tree.
This race has been around for a little over a year, and no one noticed
until two months ago; it only happens under fairly exotic conditions,
and in fact even after trying very hard to create a simple repro under
lab conditions, we could only reproduce the problem and confirm the
fix on production servers running MySQL on very fast PCIe-attached
flash devices.
Given that Dave was able to hit this problem pretty quickly, if we
confirm that this commit is at fault, the only reasonable thing to do
is to revert it IMO."
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more ARM updates from Russell King.
This got a fair number of conflicts with the <asm/system.h> split, but
also with some other sparse-irq and header file include cleanups. They
all looked pretty trivial, though.
* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits)
ARM: fix Kconfig warning for HAVE_BPF_JIT
ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds
ARM: 7349/1: integrator: convert to sparse irqs
ARM: 7259/3: net: JIT compiler for packet filters
ARM: 7334/1: add jump label support
ARM: 7333/2: jump label: detect %c support for ARM
ARM: 7338/1: add support for early console output via semihosting
ARM: use set_current_blocked() and block_sigmask()
ARM: exec: remove redundant set_fs(USER_DS)
ARM: 7332/1: extract out code patch function from kprobes
ARM: 7331/1: extract out insn generation code from ftrace
ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
ARM: 7351/1: ftrace: remove useless memory checks
ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path
ARM: Versatile Express: add NO_IOPORT
ARM: get rid of asm/irq.h in asm/prom.h
ARM: 7319/1: Print debug info for SIGBUS in user faults
ARM: 7318/1: gic: refactor irq_start assignment
ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop
ARM: 7315/1: perf: add support for the Cortex-A7 PMU
...
Pull cpupower updates from Dominik Brodowski.
* git://git.kernel.org/pub/scm/linux/kernel/git/brodo/cpupowerutils:
cpupower tools: add install target to the debug tools' makefiles
cpupower tools: allow to build debug tools in a separate directory too
cpupower: Fix broken mask values
cpupower tool: allow to build in a separate directory
cpupower tool: makefile: simplify the recipe used to generate cpupower.pot target
cpupower tool: remove use of undefined variables from the clean target of the top makefile
cpupower: Fix linking with --as-needed
cpupower: Remove unneeded code and by that fix a memleak
cpupower: Fix number of idle states
cpupower: Unify cpupower-frequency-* manpages
cpupower: Add cpupower-idle-info manpage
cpupower: AMD fam14h/Ontario monitor can also be used by fam12h cpus
cpupower: Better interface for accessing AMD pci registers
Pull a few PCMCIA updates from Dominik Brodowski.
Fix up trivial conflict (modified code in question had been removed) in
drivers/pcmcia/soc_common.c.
* git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia:
pcmcia at91_cf: fix raw gpio number usage
ARM: pxa: fix error handling in pxa2xx_drv_pcmcia_probe
pcmcia: Convert to DEFINE_PCI_DEVICE_TABLE
pcmcia: convert drivers/pcmcia/* to use module_platform_driver()
pcmcia: irq: Remove IRQF_DISABLED
There has long been a limitation using software breakpoints with a
kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For
this particular patch, it will apply cleanly and has been tested all
the way back to 2.6.36.
The kprobes code uses the text_poke() function which accommodates
writing a breakpoint into a read-only page. The x86 kgdb code can
solve the problem similarly by overriding the default breakpoint
set/remove routines and using text_poke() directly.
The x86 kgdb code will first attempt to use the traditional
probe_kernel_write(), and next try using a the text_poke() function.
The break point install method is tracked such that the correct break
point removal routine will get called later on.
Cc: x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org # >= 2.6.36
Inspried-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
There is extra state information that needs to be exposed in the
kgdb_bpt structure for tracking how a breakpoint was installed. The
debug_core only uses the the probe_kernel_write() to install
breakpoints, but this is not enough for all the archs. Some arch such
as x86 need to use text_poke() in order to install a breakpoint into a
read only page.
Passing the kgdb_bpt structure to kgdb_arch_set_breakpoint() and
kgdb_arch_remove_breakpoint() allows other archs to set the type
variable which indicates how the breakpoint was installed.
Cc: stable@vger.kernel.org # >= 2.6.36
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The do_fork and sys_open tests have never worked properly on anything
other than a UP configuration with the kgdb test suite. This is
because the test suite did not fully implement the behavior of a real
debugger. A real debugger tracks the state of what thread it asked to
single step and can correctly continue other threads of execution or
conditionally stop while waiting for the original thread single step
request to return.
Below is a simple method to cause a fatal kernel oops with the kgdb
test suite on a 2 processor ARM system:
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
echo V1I1F100 > /sys/module/kgdbts/parameters/kgdbts
Very soon after starting the test the kernel will start warning with
messages like:
kgdbts: BP mismatch c002487c expected c0024878
------------[ cut here ]------------
WARNING: at drivers/misc/kgdbts.c:317 check_and_rewind_pc+0x9c/0xc4()
[<c01f6520>] (check_and_rewind_pc+0x9c/0xc4)
[<c01f595c>] (validate_simple_test+0x3c/0xc4)
[<c01f60d4>] (run_simple_test+0x1e8/0x274)
The kernel will eventually recovers, but the test suite has completely
failed to test anything useful.
This patch implements behavior similar to a real debugger that does
not rely on hardware single stepping by using only software planted
breakpoints.
In order to mimic a real debugger, the kgdb test suite now tracks the
most recent thread that was continued (cont_thread_id), with the
intent to single step just this thread. When the response to the
single step request stops in a different thread that hit the original
break point that thread will now get continued, while the debugger
waits for the thread with the single step pending. Here is a high
level description of the sequence of events.
cont_instead_of_sstep = 0;
1) set breakpoint at do_fork
2) continue
3) Save the thread id where we stop to cont_thread_id
4) Remove breakpoint at do_fork
5) Reset the PC if needed depending on kernel exception type
6) soft single step
7) Check where we stopped
if current thread != cont_thread_id {
if (here for more than 2 times for the same thead) {
### must be a really busy system, start test again ###
goto step 1
}
goto step 5
} else {
cont_instead_of_sstep = 0;
}
8) clean up and run test again if needed
9) Clear out any threads that were waiting on a break point at the
point in time the test is ended with get_cont_catch(). This
happens sometimes because breakpoints are used in place of single
stepping and some threads could have been in the debugger exception
handling queue because breakpoints were hit concurrently on
different CPUs. This also means we wait at least one second before
unplumbing the debugger connection at the very end, so as respond
to any debug threads waiting to be serviced.
Cc: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The do_fork and sys_open tests have never worked properly on anything
other than a UP configuration with the kgdb test suite. This is
because the test suite did not fully implement the behavior of a real
debugger. A real debugger tracks the state of what thread it asked to
single step and can correctly continue other threads of execution or
conditionally stop while waiting for the original thread single step
request to return.
Below is a simple method to cause a fatal kernel oops with the kgdb
test suite on a 4 processor x86 system:
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
echo V1I1F1000 > /sys/module/kgdbts/parameters/kgdbts
Very soon after starting the test the kernel will oops with a message like:
kgdbts: BP mismatch 3b7da66480 expected ffffffff8106a590
WARNING: at drivers/misc/kgdbts.c:303 check_and_rewind_pc+0xe0/0x100()
Call Trace:
[<ffffffff812994a0>] check_and_rewind_pc+0xe0/0x100
[<ffffffff81298945>] validate_simple_test+0x25/0xc0
[<ffffffff81298f77>] run_simple_test+0x107/0x2c0
[<ffffffff81298a18>] kgdbts_put_char+0x18/0x20
The warn will turn to a hard kernel crash shortly after that because
the pc will not get properly rewound to the right value after hitting
a breakpoint leading to a hard lockup.
This change is broken up into 2 pieces because archs that have hw
single stepping (2.6.26 and up) need different changes than archs that
do not have hw single stepping (3.0 and up). This change implements
the correct behavior for an arch that supports hw single stepping.
A minor defect was fixed where sys_open should be do_sys_open
for the sys_open break point test. This solves the problem of running
a 64 bit with a 32 bit user space. The sys_open() never gets called
when using the 32 bit file system for the kgdb testsuite because the
32 bit binaries invoke the compat_sys_open() call leading to the test
never completing.
In order to mimic a real debugger, the kgdb test suite now tracks the
most recent thread that was continued (cont_thread_id), with the
intent to single step just this thread. When the response to the
single step request stops in a different thread that hit the original
break point that thread will now get continued, while the debugger
waits for the thread with the single step pending. Here is a high
level description of the sequence of events.
cont_instead_of_sstep = 0;
1) set breakpoint at do_fork
2) continue
3) Save the thread id where we stop to cont_thread_id
4) Remove breakpoint at do_fork
5) Reset the PC if needed depending on kernel exception type
6) if (cont_instead_of_sstep) { continue } else { single step }
7) Check where we stopped
if current thread != cont_thread_id {
cont_instead_of_sstep = 1;
goto step 5
} else {
cont_instead_of_sstep = 0;
}
8) clean up and run test again if needed
Cc: stable@vger.kernel.org # >= 2.6.26
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
