This issue happens under the following conditions:
1. preemption is off
2. __ARCH_WANT_INTERRUPTS_ON_CTXSW is defined
3. RT scheduling class
4. SMP system
Sequence is as follows:
1.suppose current task is A. start schedule()
2.task A is enqueued pushable task at the entry of schedule()
__schedule
prev = rq->curr;
...
put_prev_task
put_prev_task_rt
enqueue_pushable_task
4.pick the task B as next task.
next = pick_next_task(rq);
3.rq->curr set to task B and context_switch is started.
rq->curr = next;
4.At the entry of context_swtich, release this cpu's rq->lock.
context_switch
prepare_task_switch
prepare_lock_switch
raw_spin_unlock_irq(&rq->lock);
5.Shortly after rq->lock is released, interrupt is occurred and start IRQ context
6.try_to_wake_up() which called by ISR acquires rq->lock
try_to_wake_up
ttwu_remote
rq = __task_rq_lock(p)
ttwu_do_wakeup(rq, p, wake_flags);
task_woken_rt
7.push_rt_task picks the task A which is enqueued before.
task_woken_rt
push_rt_tasks(rq)
next_task = pick_next_pushable_task(rq)
8.At find_lock_lowest_rq(), If double_lock_balance() returns 0,
lowest_rq can be the remote rq.
(But,If preemption is on, double_lock_balance always return 1 and it
does't happen.)
push_rt_task
find_lock_lowest_rq
if (double_lock_balance(rq, lowest_rq))..
9.find_lock_lowest_rq return the available rq. task A is migrated to
the remote cpu/rq.
push_rt_task
...
deactivate_task(rq, next_task, 0);
set_task_cpu(next_task, lowest_rq->cpu);
activate_task(lowest_rq, next_task, 0);
10. But, task A is on irq context at this cpu.
So, task A is scheduled by two cpus at the same time until restore from IRQ.
Task A's stack is corrupted.
To fix it, don't migrate an RT task if it's still running.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/CAOAMb1BHA=5fm7KTewYyke6u-8DP0iUuJMpgQw54vNeXFsGpoQ@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the sampling interrupt throttling mechanism.
It was broken in v3.2. Events were not being unthrottled. The
unthrottling mechanism required that events be checked at each
timer tick.
This patch solves this problem and also separates:
- unthrottling
- multiplexing
- frequency-mode period adjustments
Not all of them need to be executed at each timer tick.
This third version of the patch is based on my original patch +
PeterZ proposal (https://lkml.org/lkml/2012/1/7/87).
At each timer tick, for each context:
- if the current CPU has throttled events, we unthrottle events
- if context has frequency-based events, we adjust sampling periods
- if we have reached the jiffies interval, we multiplex (rotate)
We decoupled rotation (multiplexing) from frequency-mode sampling
period adjustments. They should not necessarily happen at the same
rate. Multiplexing is subject to jiffies_interval (currently at 1
but could be higher once the tunable is exposed via sysfs).
We have grouped frequency-mode adjustment and unthrottling into the
same routine to minimize code duplication. When throttled while in
frequency mode, we scan the events only once.
We have fixed the threshold enforcement code in __perf_event_overflow().
There was a bug whereby it would allow more than the authorized rate
because an increment of hwc->interrupts was not executed at the right
place.
The patch was tested with low sampling limit (2000) and fixed periods,
frequency mode, overcommitted PMU.
On a 2.1GHz AMD CPU:
$ cat /proc/sys/kernel/perf_event_max_sample_rate
2000
We set a rate of 3000 samples/sec (2.1GHz/3000 = 700000):
$ perf record -e cycles,cycles -c 700000 noploop 10
$ perf report -D | tail -21
Aggregated stats:
TOTAL events: 80086
MMAP events: 88
COMM events: 2
EXIT events: 4
THROTTLE events: 19996
UNTHROTTLE events: 19996
SAMPLE events: 40000
cycles stats:
TOTAL events: 40006
MMAP events: 5
COMM events: 1
EXIT events: 4
THROTTLE events: 9998
UNTHROTTLE events: 9998
SAMPLE events: 20000
cycles stats:
TOTAL events: 39996
THROTTLE events: 9998
UNTHROTTLE events: 9998
SAMPLE events: 20000
For 10s, the cap is 2x2000x10 = 40000 samples.
We get exactly that: 20000 samples/event.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: <stable@kernel.org> # v3.2+
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120126160319.GA5655@quad
Signed-off-by: Ingo Molnar <mingo@elte.hu>
try_to_wake_up() has a problem which may change status from TASK_DEAD to
TASK_RUNNING in race condition with SMI or guest environment of virtual
machine. As a result, exited task is scheduled() again and panic occurs.
Here is the sequence how it occurs:
----------------------------------+-----------------------------
|
CPU A | CPU B
----------------------------------+-----------------------------
TASK A calls exit()....
do_exit()
exit_mm()
down_read(mm->mmap_sem);
rwsem_down_failed_common()
set TASK_UNINTERRUPTIBLE
set waiter.task <= task A
list_add to sem->wait_list
:
raw_spin_unlock_irq()
(I/O interruption occured)
__rwsem_do_wake(mmap_sem)
list_del(&waiter->list);
waiter->task = NULL
wake_up_process(task A)
try_to_wake_up()
(task is still
TASK_UNINTERRUPTIBLE)
p->on_rq is still 1.)
ttwu_do_wakeup()
(*A)
:
(I/O interruption handler finished)
if (!waiter.task)
schedule() is not called
due to waiter.task is NULL.
tsk->state = TASK_RUNNING
:
check_preempt_curr();
:
task->state = TASK_DEAD
(*B)
<--- set TASK_RUNNING (*C)
schedule()
(exit task is running again)
BUG_ON() is called!
--------------------------------------------------------
The execution time between (*A) and (*B) is usually very short,
because the interruption is disabled, and setting TASK_RUNNING at (*C)
must be executed before setting TASK_DEAD.
HOWEVER, if SMI is interrupted between (*A) and (*B),
(*C) is able to execute AFTER setting TASK_DEAD!
Then, exited task is scheduled again, and BUG_ON() is called....
If the system works on guest system of virtual machine, the time
between (*A) and (*B) may be also long due to scheduling of hypervisor,
and same phenomenon can occur.
By this patch, do_exit() waits for releasing task->pi_lock which is used
in try_to_wake_up(). It guarantees the task becomes TASK_DEAD after
waking up.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120117174031.3118.E1E9C6FF@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds the TCO Watchdog DeviceIDs for the Intel Lynx Point PCH.
Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Let the watchdog core to check the valid value range of min_timeout/max_timeout.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Correct typo "unexpectdly" to "unexpectedly" in pnx4008_wdt.c
and stmp3xxx_wdt.c
Signed-off-by: Masanari Iida<standby24x7@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
While receiving WDIOS_DISABLECARD option for WDIOC_SETOPTIONS command,
call wafwdt_stop() to disable watchdog.
Call wafwdt_start() while receiving WDIOS_ENABLECARD option.
Current code has reverse behavior.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
While receiving WDIOS_DISABLECARD option for WDIOC_SETOPTIONS command,
call wm8350_wdt_stop() to disable watchdog.
Call wm8350_wdt_start() while receiving WDIOS_ENABLECARD option.
Current code has reverse behavior.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
It is only used in this driver, so no need to make the symbol global.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Currently the watchdog driver calls the pm_runtime_enable and never
the disable. This may cause a warning when pm_runtime_enable
checks for the count match.
Also fixes the error
/build/watchdog # insmod omap_wdt.ko
[ 44.999389] omap_wdt omap_wdt: Unbalanced pm_runtime_enable!
[ 45.011047] OMAP Watchdog Timer Rev 0x00: initial timeout 60 sec
/build/watchdog #
Attempting to fix the same by calling pm_runtime_disable.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Reimplement a call to devm_request_mem_region followed by a call to ioremap
or ioremap_nocache by a call to devm_request_and_ioremap.
The semantic patch that makes this transformation is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@nm@
expression myname;
identifier i;
@@
struct platform_driver i = { .driver = { .name = myname } };
@@
expression dev,res,size;
expression nm.myname;
@@
-if (!devm_request_mem_region(dev, res->start, size,
- \(res->name\|dev_name(dev)\|myname\))) {
- ...
- return ...;
-}
... when != res->start
(
-devm_ioremap(dev,res->start,size)
+devm_request_and_ioremap(dev,res)
|
-devm_ioremap_nocache(dev,res->start,size)
+devm_request_and_ioremap(dev,res)
)
... when any
when != res->start
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Reimplement a call to devm_request_mem_region followed by a call to ioremap
or ioremap_nocache by a call to devm_request_and_ioremap.
The variable res_size is then no longer needed.
The semantic patch that makes this transformation is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@nm@
expression myname;
identifier i;
@@
struct platform_driver i = { .driver = { .name = myname } };
@@
expression dev,res,size;
expression nm.myname;
@@
-if (!devm_request_mem_region(dev, res->start, size,
- \(res->name\|dev_name(dev)\|myname\))) {
- ...
- return ...;
-}
... when != res->start
(
-devm_ioremap(dev,res->start,size)
+devm_request_and_ioremap(dev,res)
|
-devm_ioremap_nocache(dev,res->start,size)
+devm_request_and_ioremap(dev,res)
)
... when any
when != res->start
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
* 'fixes-for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson:
mach-ux500: no MMC_CAP_SD_HIGHSPEED on Snowball
mach-ux500: enable ARM errata 764369
mach-ux500: do not override outer.inv_all
mach-ux500: musb: now musb is always in OTG mode
Commit 4a858cfc9a (arm: convert sysdev_class to a regular subsystem)
converted the samsung sysdevs into subsys_interface instances.
While the original add-function only had a (struct sys_device *)
parameter, the dev_add from subsys_interface needs
(struct device *, struct subsys_interface *)
leading to "initialized from incompatible pointer type" warnings.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
The new spi-sh driver decodes the IORESOURCE_MEM_TYPE_MASK. So, the
resource needs the IORESOURCE_MEM_32BIT.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Fix compilation breakage
arch/sh/boards/mach-se/7724/setup.c:182: error: 'V4L2_PIX_FMT_RGB565' undeclared here (not in a function)
make[3]: *** [arch/sh/boards/mach-se/7724/setup.o] Error 1
caused by commit "fbdev: sh_mobile_lcdc: Support FOURCC-based format API"
Also add other missing headers, even if compilation currently succeeds
because of their indirect inclusion via other headers.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Fixed following build warning with exynos4_defconfig.
arch/arm/mach-exynos/clock.c:33: warning: 'exynos4_clock_save' defined but not used
arch/arm/mach-exynos/clock-exynos4210.c:35: warning: 'exynos4210_clock_save' defined but not used
arch/arm/mach-exynos/clock-exynos4212.c:35: warning: 'exynos4212_clock_save' defined but not used
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
The common static default_i2c_data structure gets bus_num set by each
s3c_i2c?_set_platdata() call, except for s3c_i2c0_set_platdata(). Thus
if for instance s3c_i2c1_set_platdata() is called prior to
s3c_i2c0_set_platdata() the I2C0 controller has bus_num set to wrong value
of 1, i.e. the one from previous set_platdata call. Fix this by also setting
bus_num for I2C0.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This patch fixes the following build issue, which happens only if
SMP has been disabled:
arch/arm/mach-exynos/built-in.o: In function `exynos4_pm_resume':
arch/arm/mach-exynos/pm.c:387: undefined reference to `scu_enable'
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
When the S3C64xx CPUs were converted to clkdev mappings were added for the
I2C controllers on them. On S3C6410 a device name is specified for I2C
controller 1 but not for controller 0 which makes the code less robust as
we'll falsely return the clock for controller 0 if there's an error in the
request for controller 1.
Improve things by registering a device name for controller 0 as well. Due
to the fact that we change the numbering for controller 0 depending on if
we've registered controller 1 this requires an ifdef to choose the name.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
this patch separates fimd specific power on/off function from pm function
and the pm interfaces will call that function for power on or off.
and also removes unnecessary codes of resume function.
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
I'd like to add my colleagues who dedicated to developing and
improving our driver to maintainer entry.
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
FB based FIMD and DRM based FIMD drivers use same hardware
so with this patch, only one of them would be selected.
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
DRM_EXYNOS_HDMI driver and VIDEO_SAMSUNG_S5P_TV driver should be
not enabled at once because they use same HW blocks. So dependency
for DRM_EXYNOS_HDMI is fixed to check VIDEO_SAMSUNG_S5P_TV=n.
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
To make a api pair of request_mem_region and release_mem_region,
release_mem_region is used instead of release_resource.
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Add missing iounmap in error handling code, in a case where the function
already preforms iounmap on some other execution path.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e;
statement S,S1;
int ret;
@@
e = \(ioremap\|ioremap_nocache\)(...)
... when != iounmap(e)
if (<+...e...+>) S
... when any
when != iounmap(e)
*if (...)
{ ... when != iounmap(e)
return ...; }
... when any
iounmap(e);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Tony Lindgren <tony@atomide.com>
pdata needs to be freed before leaving the function in an error case.
A simplified version of the semantic match that finds the problem is as
follows: (http://coccinelle.lip6.fr)
// <smpl>
@r exists@
local idexpression x;
statement S;
identifier f1;
position p1,p2;
expression *ptr != NULL;
@@
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
when != if (...) { <+...x...+> }
x->f1
...>
(
return \(0\|<+...x...+>\|ptr\);
|
return@p2 ...;
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Currently MMC2 setup code can only enable loopback clock and
relies on reset value for boards that need to have it disabled.
This causes a problem with certain bootloaders that always enable
that clock, resulting with unwanted bootloader dependencies.
Fix this by making it disable the clock if board data says so.
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Tony Lindgren <tony@atomide.com>
hsmmc23_before_set_reg() can set MMCSDIO2ADPCLKISEL bit, which
enables internal clock for MMC2. Currently this function is also called
by code handling MMC3, and if .internal_clock is set in platform data
(by default it currently is), it will set MMCSDIO2ADPCLKISEL for MMC2
instead of MMC3 (MMC3 doesn't have such bit so nothing actually needs to
be done). This breaks 2nd SD slot on pandora.
Fix this by changing hsmmc23_before_set_reg() to only handle MMC2.
Note that this removes .remux() call for MMC3, but no board currently
needs it and it's also not called for MMC4 and MMC5.
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
following statement can only change device size from 8-bit(0) to 16-bit(1),
but not vice versa:
regval |= GPMC_CONFIG1_DEVICESIZE(wval);
so as this field has 1 reserved bit, that could be used in future,
just clear both bits and then OR with the desired value
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tony Lindgren <tony@atomide.com>
Commit 2f0778af (ARM: 7205/2: sched_clock: allow sched_clock to be
selected at runtime) had a typo for the case when CONFIG_OMAP_32K_TIMER
is not set.
In dmtimer_read_sched_clock(), wrong argument was getting passed to
__omap_dm_timer_read_counter() function call; instead of "&clksrc",
we were passing "clksrc.io_base", which results into kernel crash.
To reproduce kernel crash, just disable the CONFIG_OMAP_32K_TIMER config
option (and DEBUG_LL) and build/boot the kernel.
This will use dmtimer as a kernel clocksource and lead to kernel
crash during boot -
[ 0.000000] OMAP clocksource: GPTIMER2 at 26000000 Hz
[ 0.000000] sched_clock: 32 bits at 26MHz, resolution 38ns, wraps every
165191ms
[ 0.000000] Unable to handle kernel paging request at virtual address
00030ef1
[ 0.000000] pgd = c0004000
[ 0.000000] [00030ef1] *pgd=00000000
[ 0.000000] Internal error: Oops: 5 [#1] SMP
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 Not tainted (3.3.0-rc1-11574-g0c76665-dirty #3)
[ 0.000000] PC is at dmtimer_read_sched_clock+0x18/0x4c
[ 0.000000] LR is at update_sched_clock+0x10/0x84
[ 0.000000] pc : [<c00243b8>] lr : [<c0018684>] psr: 200001d3
[ 0.000000] sp : c0641f38 ip : c0641e18 fp : 0000000a
[ 0.000000] r10: 151c3303 r9 : 00000026 r8 : 76276259
[ 0.000000] r7 : 00028547 r6 : c065ac80 r5 : 431bde82 r4 : c0655968
[ 0.000000] r3 : 00030ef1 r2 : fb032000 r1 : 00000028 r0 : 00000001
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
[tony@atomide.com: updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>
Commit 36a1211970 removed linux/module.h
include statement from one of the headers that end up in net/sock.h.
It was providing us with static_branch() definition implicitly, so
after its removal the build got broken.
To fix this, and avoid having this happening in the future,
let me do the right thing and include linux/jump_label.h
explicitly in sock.h.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
CC: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Audigy's SB1394 controller is actually from Texas Instruments
and has the same bus reset packet generation bug, so it needs the
same quirk entry.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: 2.6.36+ <stable@vger.kernel.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Setting link parameters on a netdevice changes the value
of if_nlmsg_size(), therefore it is necessary to recalculate
min_ifinfo_dump_size.
Signed-off-by: Stefan Gula <steweg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
