Regarding the bug addressed in:
4cd4262: sched: prevent divide by zero error in cpu_avg_load_per_task
Linus points out that the fix is not complete:
> There's nothing that keeps gcc from deciding not to reload
> rq->nr_running.
>
> Of course, in _practice_, I don't think gcc ever will (if it decides
> that it will spill, gcc is likely going to decide that it will
> literally spill the local variable to the stack rather than decide to
> reload off the pointer), but it's a valid compiler optimization, and
> it even has a name (rematerialization).
>
> So I suspect that your patch does fix the bug, but it still leaves the
> fairly unlikely _potential_ for it to re-appear at some point.
>
> We have ACCESS_ONCE() as a macro to guarantee that the compiler
> doesn't rematerialize a pointer access. That also would clarify
> the fact that we access something unsafe outside a lock.
So make sure our nr_running value is immutable and cannot change
after we check it for nonzero.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
this warning:
kernel/cpuset.c: In function ‘generate_sched_domains’:
kernel/cpuset.c:588: warning: ‘ndoms’ may be used uninitialized in this function
triggers because GCC does not recognize that ndoms stays uninitialized
only if doms is NULL - but that flow is covered at the end of
generate_sched_domains().
Help out GCC by initializing this variable to 0. (that's prudent anyway)
Also, this function needs a splitup and code flow simplification:
with 160 lines length it's clearly too long.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
An intermediate transition from _RUNNING to _IN_SHUTDOWN could have been
missed by the former code.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
If there is more than one FireWire controller present, dummy_zero_addr
and dummy_max_addr were added multiple times to different lists, thus
corrupting the lists. Fix this by allocating them dynamically per host
instead of just once globally.
(Perhaps a better address space allocation algorithm could rid us of the
two dummy address spaces.)
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=10129 .
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Impact: fix typo in documentation
TPPROTO is misspelt in Documentation/tracepoints.txt
Kept me wondering what was wrong, when I was trying to add a new tracepoint
subsystem.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix build error on branch tracer
This should fix a build error reported on alpha in linux-next:
CC kernel/trace/trace_branch.o
kernel/trace/trace_branch.c: In function 'probe_likely_condition':
kernel/trace/trace_branch.c:44: error: implicit declaration of function 'raw_local_irq_save'
kernel/trace/trace_branch.c:76: error: implicit declaration of function 'raw_local_irq_restore'
Unfortunately, I can't test it since I don't have any Alpha build environment.
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 7ff93f8b ("mlx4_core: Multiple port type support") introduced
support for different port types. As part of that support, SET_PORT
is invoked to set the port type during driver startup. However, as a
side-effect, for IB ports the invocation of this command also sets the
port's capability mask to zero (losing the default value set by FW).
To fix this, get the default ib port capabilities (via a MAD_IFC Port
Info query) during driver startup, and save them for use in the
mlx4_SET_PORT command when setting the port-type to Infiniband.
This patch fixes problems with subnet manager (SM) failover such as
<https://bugs.openfabrics.org/show_bug.cgi?id=1183>, which occurred
because the IsTrapSupported bit in the capability mask was zeroed.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
the toshiba ACPI driver will, in a failure case, free the rfkill state
before stopping the polling timer that would use this state. More interesting,
in the same failure case handling, it calls the exit function, which also
frees the rfkill state, but after stopping the polling.
If the race happens, a NULL pointer is passed to rfkill_force_state()
which then causes a nice dereference.
Fix the race by just not doing the too-early freeing of the rfkill state.
This appears to be the cause of a hot issue on kerneloops.org; while I
have no solid evidence of that this patch will fix the issue, the race
appears rather real.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
mangle_path() is trivial enough to make export restrictions on it
pointless - so change the export from EXPORT_SYMBOL_GPL to EXPORT_SYMBOL.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Add document and comments on marker_synchronize_unregister(): it
should be called before freeing resources that the probes depend on.
Based on comments from Lai Jiangshan and Mathieu Desnoyers.
Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
i2c clients should be removed in reverse order compared to the probe
(actually: bind) order. This matters when several clients depend on
each other.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Build fixes for isp1301_omap; no behavior changes:
- fix incorrect probe() signature (it changed many months ago)
- provide missing functions on H3 and H4 boards
- "sparse" fixes (static, NULL-vs-0)
The H3 build bits subset some of the stuff that was previously in
the OMAP tree but never went to mainline.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
While parsing 'hid_blacklist' in the apple alu wireless keyboard is not found.
This happens because in the blacklist it is declared with HID_USB_DEVICE
although the keyboards are really bluetooth devices. The same holds for
'apple_devices' list.
This patch fixes it by changing HID_USB_DEVICE to HID_BLUETOOTH_DEVICE in those
two lists.
Signed-off-by: Jan Scholz <Scholz@fias.uni-frankfurt.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Impact: fix for PowerPC 32 code
There were some early init code that was not safe for static
ftrace to boot on my PowerBook. This code must only use relative
addressing, and static mcount performs a compare of the
ftrace_trace_function pointer, and gets that with an absolute address.
In the early init boot up code, this will cause a fault.
This patch removes tracing from the files containing the offending
functions.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: clean up
Paul Mackerras pointed out that the code to determine if the branch
can reach the destination is incorrect. Michael Ellerman suggested
to pull out the code from create_branch and use that.
Simply using create_branch is probably the best.
Reported-by: Michael Ellerman <michael@ellerman.id.au>
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix to PowerPC code modification
After modifying code it is essential to flush the icache. This patch
adds the missing flush.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: clean up and robustness addition
This patch addresses the comments made by Paul Mackerras.
It removes the type casting between unsigned int and unsigned char
pointers, and replaces them with a use of all unsigned int.
Verification that the jump is indeed made to a trampoline has also
been added.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: quicken mcount calls that are not replaced by dyn ftrace
Dynamic ftrace no longer does on the fly recording of mcount locations.
The mcount locations are now found at compile time. The mcount
function no longer needs to store registers and call a stub function.
It can now just simply return.
Since there are some functions that do not get converted to a nop
(.init sections and other code that may disappear), this patch should
help speed up that code.
Also, the stub for mcount on PowerPC 32 can not be a simple branch
link register like it is on PowerPC 64. According to the ABI specification:
"The _mcount routine is required to restore the link register from
the stack so that the profiling code can be inserted transparently,
whether or not the profiled function saves the link register itself."
This means that we must restore the link register that was used
to make the call to mcount. The minimal mcount function for PPC32
ends up being:
mcount:
mflr r0
mtctr r0
lwz r0, 4(r1)
mtlr r0
bctr
Where we move the link register used to call mcount into the
ctr register, and then restore the link register from the stack.
Then we use the ctr register to jump back to the mcount caller.
The r0 register is free for us to use.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: extend documentation with notice of using wild cards correctly
We know that we can use wild cards to set set_ftrace_filter, but there's
problem when using them naively such as:
echo h* > /debug/tracing/set_ftrace_filter
If there are files named with "h" prefix in current directory,
echo "h*" will echo these filenames to set_ftrace_filter, not the
intended "h*".
For example:
$ cat /debug/tracing/available_filter_functions |grep ^hr |wc -l
23
$ ls
$ touch hraa hrdd
$ ls
hraa hrdd
$ echo hr* > /debug/tracing/set_ftrace_filter
$ cat /debug/tracing/set_ftrace_filter
No output in /debug/tracing/set_ftrace_filter!
If we use '' to escape wild cards, it works:
$ ls
hraa hrdd
$ echo "hr*" > /debug/tracing/set_ftrace_filter
$ cat /debug/tracing/set_ftrace_filter |wc -l
23
This problem can lead to unexpected result if current directory has a
lot of files.
Signed-off-by: walimis <walimisdev@gmail.com>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make ftrace position computing more sane
First remove useless ->pos field. Then we needn't check seq_printf
in .show like other place.
Signed-off-by: Liming Wang <liming.wang@windriver.com>
Reviewed-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There are architectures that still have no stacktrace support.
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: increase the visual qualities of the call-graph-tracer output
This patch applies various trace output formatting changes:
- CPU is now a decimal number, followed by a parenthesis.
- Overhead is now on the second column (gives a good visibility)
- Cost is now on the third column, can't exceed 9999.99 us. It is
followed by a virtual line based on a "|" character.
- Functions calls are now the last column on the right. This way, we
haven't dynamic column (which flow is harder to follow) on its right.
- CPU and Overhead have their own option flag. They are default-on but you
can disable them easily:
echo nofuncgraph-cpu > trace_options
echo nofuncgraph-overhead > trace_options
TODO:
_ Refactoring of the thread switch output.
_ Give a default-off option to output the thread and its pid on each row.
_ Provide headers
_ ....
Here is an example of the new trace style:
0) | mutex_unlock() {
0) 0.639 us | __mutex_unlock_slowpath();
0) 1.607 us | }
0) | remove_wait_queue() {
0) 0.616 us | _spin_lock_irqsave();
0) 0.616 us | _spin_unlock_irqrestore();
0) 2.779 us | }
0) 0.495 us | n_tty_set_room();
0) ! 9999.999 us | }
0) | tty_ldisc_deref() {
0) 0.615 us | _spin_lock_irqsave();
0) 0.616 us | _spin_unlock_irqrestore();
0) 2.793 us | }
0) | current_fs_time() {
0) 0.488 us | current_kernel_time();
0) 0.495 us | timespec_trunc();
0) 2.486 us | }
0) ! 9999.999 us | }
0) ! 9999.999 us | }
0) ! 9999.999 us | }
0) | sys_read() {
0) 0.796 us | fget_light();
0) | vfs_read() {
0) | rw_verify_area() {
0) | security_file_permission() {
0) 0.488 us | cap_file_permission();
0) 1.720 us | }
0) 3. 4 us | }
0) | tty_read() {
0) 0.488 us | tty_paranoia_check();
0) | tty_ldisc_ref_wait() {
0) | tty_ldisc_try() {
0) 0.615 us | _spin_lock_irqsave();
0) 0.615 us | _spin_unlock_irqrestore();
0) 5.436 us | }
0) 6.427 us | }
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With aliasing VIPT cache support, the ARM implementation of
clear_user_page() and copy_user_page() sets up a temporary kernel space
mapping such that we have the same cache colour as the userspace page.
This avoids having to consider any userspace aliases from this operation.
However, when highmem is enabled, kmap_atomic() have to setup mappings.
The copy_user_highpage() and clear_user_highpage() call these functions
before delegating the copies to copy_user_page() and clear_user_page().
The effect of this is that each of the *_user_highpage() functions setup
their own kmap mapping, followed by the *_user_page() functions setting
up another mapping. This is rather wasteful.
Thankfully, copy_user_highpage() can be overriden by architectures by
defining __HAVE_ARCH_COPY_USER_HIGHPAGE. However, replacement of
clear_user_highpage() is more difficult because its inline definition
is not conditional. It seems that you're expected to define
__HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and provide a replacement
__alloc_zeroed_user_highpage() implementation instead.
The allocation itself is fine, so we don't want to override that. What
we really want to do is to override clear_user_highpage() with our own
version which doesn't kmap_atomic() unnecessarily.
Other VIPT architectures (PARISC and SH) would also like to override
this function as well.
Acked-by: Hugh Dickins <hugh@veritas.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
udf_clear_inode() can leave behind buffers on mapping's i_private list (when
we truncated preallocation). Call invalidate_inode_buffers() so that the list
is properly cleaned-up before we return from udf_clear_inode(). This is ugly
and suggest that we should cleanup preallocation earlier than in clear_inode()
but currently there's no such call available since drop_inode() is called under
inode lock and thus is unusable for disk operations.
Signed-off-by: Jan Kara <jack@suse.cz>
Impact: fix boot crash on AMD IOMMU if CONFIG_GART_IOMMU is off
Currently these macros evaluate to a no-op except the kernel is compiled
with GART or Calgary support. But we also need these macros when we have
SWIOTLB, VT-d or AMD IOMMU in the kernel. Since we always compile at
least with SWIOTLB we can define these macros always.
This patch is also for stable backport for the same reason the SWIOTLB
default selection patch is.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We need an alignment of 16384 bytes for the initial kernel stack if
the kernel is configured for 16384 bytes stacks but the linker script
currently guarantees only an alignment of 8192 bytes.
So fix this and simply use THREAD_SIZE as alignment value which will
always do the right thing.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When running several kvm processes with lots of memory overcommitment,
we have seen an oops during process shutdown:
------------[ cut here ]------------
Kernel BUG at 0000000000193434 [verbose debug info unavailable]
addressing exception: 0005 [#1] PREEMPT SMP
Modules linked in: kvm sunrpc qeth_l2 dm_mod qeth ccwgroup
CPU: 10 Not tainted 2.6.28-rc4-kvm-bigiron-00521-g0ccca08-dirty #8
Process kuli (pid: 14460, task: 0000000149822338, ksp: 0000000024f57650)
Krnl PSW : 0704e00180000000 0000000000193434 (unmap_vmas+0x884/0xf10)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3
Krnl GPRS: 0000000000000002 0000000000000000 000000051008d000 000003e05e6034e0
00000000001933f6 00000000000001e9 0000000407259e0a 00000002be88c400
00000200001c1000 0000000407259608 0000000407259e08 0000000024f577f0
0000000407259e09 0000000000445fa8 00000000001933f6 0000000024f577f0
Krnl Code: 0000000000193426: eb22000c000d sllg %r2,%r2,12
000000000019342c: a7180000 lhi %r1,0
0000000000193430: b2290012 iske %r1,%r2
>0000000000193434: a7110002 tmll %r1,2
0000000000193438: a7840006 brc 8,193444
000000000019343c: 9602c000 oi 0(%r12),2
0000000000193440: 96806000 oi 0(%r6),128
0000000000193444: a7110004 tmll %r1,4
Call Trace:
([<00000000001933f6>] unmap_vmas+0x846/0xf10)
[<0000000000199680>] exit_mmap+0x210/0x458
[<000000000012a8f8>] mmput+0x54/0xfc
[<000000000012f714>] exit_mm+0x134/0x144
[<000000000013120c>] do_exit+0x240/0x878
[<00000000001318dc>] do_group_exit+0x98/0xc8
[<000000000013e6b0>] get_signal_to_deliver+0x30c/0x358
[<000000000010bee0>] do_signal+0xec/0x860
[<0000000000112e30>] sysc_sigpending+0xe/0x22
[<000002000013198a>] 0x2000013198a
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<00000000001a68d0>] free_swap_and_cache+0x1a0/0x1a4
<4>---[ end trace bc19f1d51ac9db7c ]---
The faulting instruction is the storage key operation (iske) in
ptep_rcp_copy (called by pte_clear, called by unmap_vmas). iske
reads dirty and reference bit information for a physical page and
requires a valid physical address. Since we are in pte_clear, we
cannot rely on the pte containing a valid address. Fortunately we
dont need these information in pte_clear - after all there is no
mapping. The best fix is to remove the needless call to ptep_rcp_copy
that contains the iske.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
CONFIG_PRINTK_TIME reveals that sched_clock has a wrong offset during boot:
..
[ 0.000000] Movable zone: 0 pages used for memmap
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 775679
[ 0.000000] Kernel command line: dasd=4b6c root=/dev/dasda1 ro noinitrd
[ 0.000000] PID hash table entries: 4096 (order: 12, 32768 bytes)
[6920575.975232] console [ttyS0] enabled
[6920575.987586] Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes)
[6920575.991404] Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes)
..
The s390 implementation of sched_clock uses the store clock instruction and
subtracts jiffies_timer_cc.
jiffies_timer_cc is a local variable in arch/s390/kernel/time.c and only used
for sched_clock and monotonic clock. For historical reasons there is an offset
on that value. With todays code this offset is unnecessary. By removing that
offset we can get a sched_clock which returns the nanoseconds after time_init.
This improves CONFIG_PRINTK_TIME.
Since sched_clock is the only user, I have also renamed jiffies_timer_cc to
sched_clock_base_cc. In addition, the local variable init_timer_cc is redundant
and can be romved as well.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
syscall_get_nr() currently returns a valid result only if the call
chain of the traced process includes do_syscall_trace_enter(). But
collect_syscall() can be called for any sleeping task, the result of
syscall_get_nr() in general is completely bogus.
To make syscall_get_nr() work for any sleeping task the traps field
in pt_regs is replace with svcnr - the system call number the process
is executing. If svcnr == 0 the process is not on a system call path.
The syscall_get_arguments and syscall_set_arguments use regs->gprs[2]
for the first system call parameter. This is incorrect since gprs[2]
may have been overwritten with the system call number if the call
chain includes do_syscall_trace_enter. Use regs->orig_gprs2 instead.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Impact: enhance the output of the graph-tracer
This patch applies some ideas of Ingo Molnar and Steven Rostedt.
* Output leaf functions in one line with parenthesis, semicolon and duration
output.
* Add a second column (after cpu) for an overhead sign.
if duration > 100 us, "!"
if duration > 10 us, "+"
else " "
* Print output in us with remaining nanosec: u.n
* Print duration on the right end, following the indentation of the functions.
Use also visual clues: "-" on entry call (no duration to output) and "+" on
return (duration output).
The name of the tracer has been fixed as well: function-branch becomes
function_branch.
Here is an example of the new output:
CPU[000] dequeue_entity() { -
CPU[000] update_curr() { -
CPU[000] update_min_vruntime(); + 0.512 us
CPU[000] } + 1.504 us
CPU[000] clear_buddies(); + 0.481 us
CPU[000] update_min_vruntime(); + 0.504 us
CPU[000] } + 4.557 us
CPU[000] hrtick_update() { -
CPU[000] hrtick_start_fair(); + 0.489 us
CPU[000] } + 1.443 us
CPU[000] + } + 14.655 us
CPU[000] + } + 15.678 us
CPU[000] + } + 16.686 us
CPU[000] msecs_to_jiffies(); + 0.481 us
CPU[000] put_prev_task_fair(); + 0.504 us
CPU[000] pick_next_task_fair(); + 0.482 us
CPU[000] pick_next_task_rt(); + 0.504 us
CPU[000] pick_next_task_fair(); + 0.481 us
CPU[000] pick_next_task_idle(); + 0.489 us
CPU[000] _spin_trylock(); + 0.655 us
CPU[000] _spin_unlock(); + 0.609 us
CPU[000] ------------8<---------- thread bash-2794 ------------8<----------
CPU[000] finish_task_switch() { -
CPU[000] _spin_unlock_irq(); + 0.722 us
CPU[000] } + 2.369 us
CPU[000] ! } + 501972.605 us
CPU[000] ! } + 501973.763 us
CPU[000] copy_from_read_buf() { -
CPU[000] _spin_lock_irqsave(); + 0.670 us
CPU[000] _spin_unlock_irqrestore(); + 0.699 us
CPU[000] copy_to_user() { -
CPU[000] might_fault() { -
CPU[000] __might_sleep(); + 0.503 us
CPU[000] } + 1.632 us
CPU[000] __copy_to_user_ll(); + 0.542 us
CPU[000] } + 3.858 us
CPU[000] tty_audit_add_data() { -
CPU[000] _spin_lock_irq(); + 0.609 us
CPU[000] _spin_unlock_irq(); + 0.624 us
CPU[000] } + 3.196 us
CPU[000] _spin_lock_irqsave(); + 0.624 us
CPU[000] _spin_unlock_irqrestore(); + 0.625 us
CPU[000] + } + 13.611 us
CPU[000] copy_from_read_buf() { -
CPU[000] _spin_lock_irqsave(); + 0.624 us
CPU[000] _spin_unlock_irqrestore(); + 0.616 us
CPU[000] } + 2.820 us
CPU[000]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix divide by zero crash in scheduler rebalance irq
While testing the branch profiler, I hit this crash:
divide error: 0000 [#1] PREEMPT SMP
[...]
RIP: 0010:[<ffffffff8024a008>] [<ffffffff8024a008>] cpu_avg_load_per_task+0x50/0x7f
[...]
Call Trace:
<IRQ> <0> [<ffffffff8024fd43>] find_busiest_group+0x3e5/0xcaa
[<ffffffff8025da75>] rebalance_domains+0x2da/0xa21
[<ffffffff80478769>] ? find_next_bit+0x1b2/0x1e6
[<ffffffff8025e2ce>] run_rebalance_domains+0x112/0x19f
[<ffffffff8026d7c2>] __do_softirq+0xa8/0x232
[<ffffffff8020ea7c>] call_softirq+0x1c/0x3e
[<ffffffff8021047a>] do_softirq+0x94/0x1cd
[<ffffffff8026d5eb>] irq_exit+0x6b/0x10e
[<ffffffff8022e6ec>] smp_apic_timer_interrupt+0xd3/0xff
[<ffffffff8020e4b3>] apic_timer_interrupt+0x13/0x20
The code for cpu_avg_load_per_task has:
if (rq->nr_running)
rq->avg_load_per_task = rq->load.weight / rq->nr_running;
The runqueue lock is not held here, and there is nothing that prevents
the rq->nr_running from going to zero after it passes the if condition.
The branch profiler simply made the race window bigger.
This patch saves off the rq->nr_running to a local variable and uses that
for both the condition and the division.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: prevent unnecessary stack recursion
if the resched flag was set before we entered, then don't reschedule.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
A generic work-around from ACPICA is in the queue,
but since Linux has a work-around in its battery
driver, we can disable this warning now.
Allow _BIF method to return an Package with Buffer elements
http://bugzilla.kernel.org/show_bug.cgi?id=11822
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Linux will continue to ignore OSI(Linux),
except for a white-list containing a few systems.
So delete the black-list,
and stop soliciting user-feedback on the console.
Signed-off-by: Len Brown <len.brown@intel.com>
This can happen if the _WAK method returns nothing (as per ACPI
1.0) but does return an integer if the implicit return mechanism
is enabled. This is the only method that has this problem,
since it is also defined to return a package of two integers
(ACPI 1.0b+). In all other cases, if a method returns an object
when one was not expected, no warning is issued.
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>
This fixes a regression from v2.6.27, caused by commit
5814f737e1cd2cfa2893badd62189acae3e1e1fd, "ACPI: thinkpad-acpi:
attempt to preserve fan state on resume".
It is possible for fan_suspend() to fail to properly initialize
fan_control_desired_level as required by fan_resume(), resulting on
the fan always being set to level 7 on resume if the user didn't
touch the fan controller.
In order to get fan sleep/resume handling to work right:
1. Fix the fan_suspend handling of the T43 firmware quirk. If it is
still undefined, we didn't touch the fan yet and that means we have no
business doing it on resume.
2. Store the fan level on its own variable to avoid any possible
issues with hijacking fan_control_desired_level (which isn't supposed
to have anything other than 0-7 in it, anyway).
3. Change the fan_resume code to me more straightforward to understand
(although we DO optimize the boolean logic there, otherwise it looks
disgusting).
4. Add comments to help understand what the code is supposed to be
doing.
5. Change fan_set_level to be less strict about how auto and
full-speed modes are requested.
http://bugzilla.kernel.org/show_bug.cgi?id=11982
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Reported-by: Tino Keitel <tino.keitel@tikei.de>
Signed-off-by: Len Brown <len.brown@intel.com>
There's no need to print "Sony: " just after "sony-laptop: " (DRV_PFX).
Signed-off-by: Alessandro Guido <ag@alessandroguido.name>
Signed-off-by: Len Brown <len.brown@intel.com>
After commit 540b8bb9c33935183ceb5bed466a42ad72b2af56:
sony-laptop: fingers off backlight if video.ko is serving this functionality
I can't set brightness on my sony laptop (nothing in /sys/class/backlight).
dmesg says "sony-laptop: Sony: Brightness ignored, must be controlled by ACPI
video driver".
The function acpi_video_backlight_support returns 0 if we should use the
vendor-specific backlight support, while non-0 if the ACPI generic should
be used. Because of this, the check introduced by the said commit appears
reversed.
Signed-off-by: Alessandro Guido <ag@alessandroguido.name>
Signed-off-by: Len Brown <len.brown@intel.com>
Some Apple boxes evidently require us to set SCI_EN on resume
directly, because if we don't do that, they hung somewhere in the
resume code path. Moreover, on these boxes it is not sufficient to
use acpi_enable() to turn ACPI on during resume. All of this is
against the ACPI specification which states that (1) the BIOS is
supposed to return from the S3 sleep state with ACPI enabled
(SCI_EN set) and (2) the SCI_EN bit is owned by the hardware and we
are not supposed to change it.
For this reason, blacklist the affected systems so that the SCI_EN
bit is set during resume on them.
[NOTE: Unconditional setting SCI_EN for all system on resume doesn't
work, because it makes some other systems crash (that's to be
expected). Also, it is not entirely clear right now if all of the
Apple boxes require this workaround.]
This patch fixes the recent regression tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=12038
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Tino Keitel <tino.keitel@gmx.de>
Tested-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Now I know why I had strange "scheduling in atomic" problems:
acpi_evaluate_integer() does malloc(..., irqs_disabled() ? GFP_ATOMIC
: GFP_KERNEL)... which is (of course) broken.
There's no way to reliably tell if we need GFP_ATOMIC or not from
code, this one for example fails to detect spinlocks held.
Fortunately, allocation seems small enough to be done on stack.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Acked-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Use the correct wake-up enable register, and make it
work with 34xx also.
Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
ACPI battery interface reports its state either in mW or in mA, and
discharge rate in your case is reported in mW. power_supply interface
does not have such a parameter, so current_now parameter is used
for all cases. But in case of mW, reported discharge should
be converted into mA.
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: Len Brown <len.brown@intel.com>
Ingo Molnar