Commit Graph

189397 Commits

Author SHA1 Message Date
Oleg Nesterov
9084bb8246 sched: Make select_fallback_rq() cpuset friendly
Introduce cpuset_cpus_allowed_fallback() helper to fix the cpuset problems
with select_fallback_rq(). It can be called from any context and can't use
any cpuset locks including task_lock(). It is called when the task doesn't
have online cpus in ->cpus_allowed but ttwu/etc must be able to find a
suitable cpu.

I am not proud of this patch. Everything which needs such a fat comment
can't be good even if correct. But I'd prefer to not change the locking
rules in the code I hardly understand, and in any case I believe this
simple change make the code much more correct compared to deadlocks we
currently have.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091027.GA9155@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:03 +02:00
Oleg Nesterov
6a1bdc1b57 sched: _cpu_down(): Don't play with current->cpus_allowed
_cpu_down() changes the current task's affinity and then recovers it at
the end. The problems are well known: we can't restore old_allowed if it
was bound to the now-dead-cpu, and we can race with the userspace which
can change cpu-affinity during unplug.

_cpu_down() should not play with current->cpus_allowed at all. Instead,
take_cpu_down() can migrate the caller of _cpu_down() after __cpu_disable()
removes the dying cpu from cpu_online_mask.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091023.GA9148@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:03 +02:00
Oleg Nesterov
30da688ef6 sched: sched_exec(): Remove the select_fallback_rq() logic
sched_exec()->select_task_rq() reads/updates ->cpus_allowed lockless.
This can race with other CPUs updating our ->cpus_allowed, and this
looks meaningless to me.

The task is current and running, it must have online cpus in ->cpus_allowed,
the fallback mode is bogus. And, if ->sched_class returns the "wrong" cpu,
this likely means we raced with set_cpus_allowed() which was called
for reason, why should sched_exec() retry and call ->select_task_rq()
again?

Change the code to call sched_class->select_task_rq() directly and do
nothing if the returned cpu is wrong after re-checking under rq->lock.

From now task_struct->cpus_allowed is always stable under TASK_WAKING,
select_fallback_rq() is always called under rq-lock or the caller or
the caller owns TASK_WAKING (select_task_rq).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091019.GA9141@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:02 +02:00
Oleg Nesterov
c1804d547d sched: move_task_off_dead_cpu(): Remove retry logic
The previous patch preserved the retry logic, but it looks unneeded.

__migrate_task() can only fail if we raced with migration after we dropped
the lock, but in this case the caller of set_cpus_allowed/etc must initiate
migration itself if ->on_rq == T.

We already fixed p->cpus_allowed, the changes in active/online masks must
be visible to racer, it should migrate the task to online cpu correctly.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091014.GA9138@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:02 +02:00
Oleg Nesterov
1445c08d06 sched: move_task_off_dead_cpu(): Take rq->lock around select_fallback_rq()
move_task_off_dead_cpu()->select_fallback_rq() reads/updates ->cpus_allowed
lockless. We can race with set_cpus_allowed() running in parallel.

Change it to take rq->lock around select_fallback_rq(). Note that it is not
trivial to move this spin_lock() into select_fallback_rq(), we must recheck
the task was not migrated after we take the lock and other callers do not
need this lock.

To avoid the races with other callers of select_fallback_rq() which rely on
TASK_WAKING, we also check p->state != TASK_WAKING and do nothing otherwise.
The owner of TASK_WAKING must update ->cpus_allowed and choose the correct
CPU anyway, and the subsequent __migrate_task() is just meaningless because
p->se.on_rq must be false.

Alternatively, we could change select_task_rq() to take rq->lock right
after it calls sched_class->select_task_rq(), but this looks a bit ugly.

Also, change it to not assume irqs are disabled and absorb __migrate_task_irq().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091010.GA9131@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:01 +02:00
Oleg Nesterov
897f0b3c3f sched: Kill the broken and deadlockable cpuset_lock/cpuset_cpus_allowed_locked code
This patch just states the fact the cpusets/cpuhotplug interaction is
broken and removes the deadlockable code which only pretends to work.

- cpuset_lock() doesn't really work. It is needed for
  cpuset_cpus_allowed_locked() but we can't take this lock in
  try_to_wake_up()->select_fallback_rq() path.

- cpuset_lock() is deadlockable. Suppose that a task T bound to CPU takes
  callback_mutex. If cpu_down(CPU) happens before T drops callback_mutex
  stop_machine() preempts T, then migration_call(CPU_DEAD) tries to take
  cpuset_lock() and hangs forever because CPU is already dead and thus
  T can't be scheduled.

- cpuset_cpus_allowed_locked() is deadlockable too. It takes task_lock()
  which is not irq-safe, but try_to_wake_up() can be called from irq.

Kill them, and change select_fallback_rq() to use cpu_possible_mask, like
we currently do without CONFIG_CPUSETS.

Also, with or without this patch, with or without CONFIG_CPUSETS, the
callers of select_fallback_rq() can race with each other or with
set_cpus_allowed() pathes.

The subsequent patches try to to fix these problems.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091003.GA9123@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:01 +02:00
Li Zefan
25c2d55c00 sched: Remove USER_SCHED from documentation
USER_SCHED has been removed, so update the documentation
accordingly.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
LKML-Reference: <4BA9A07E.8070508@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:01 +02:00
Li Zefan
32bd7eb5a7 sched: Remove remaining USER_SCHED code
This is left over from commit 7c9414385e ("sched: Remove USER_SCHED"")

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Howells <dhowells@redhat.com>
LKML-Reference: <4BA9A05F.7010407@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:00 +02:00
Ingo Molnar
c9494727cf Merge branch 'linus' into sched/core
Merge reason: update to latest upstream

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:03:08 +02:00
Linus Torvalds
42be79e37e Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (76 commits)
  drm/radeon/kms: enable ACPI powermanagement mode on radeon gpus.
  drm/radeon/kms: rs400/480 should set common registers.
  drm/radeon/kms: add sanity check to wptr.
  drm/radeon/kms/evergreen: get DP working
  drm/radeon/kms: add hw_i2c module option
  drm/radeon/kms: use new pre/post_xfer i2c bit algo hooks
  drm/radeon/kms: disable MSI on IGP chips
  drm/radeon/kms: display watermark updates (v2)
  drm/radeon/kms/dp: disable training pattern on the sink at the end of link training
  drm/radeon/kms: minor fixes for eDP with LCD* device tags (v2)
  drm/radeon/kms/dp: remove extraneous training complete call
  drm/radeon/kms/atom: minor fixes to transmitter setup
  drm/radeon/kms: Only restrict BO to visible VRAM size when pinning to VRAM.
  drm: fix build error when SYSRQ is disabled
  drm/radeon/kms: fix macbookpro connector quirk
  drm/radeon/r6xx/r7xx: further safe reg clean up
  drm/radeon: bump the UMS driver version for r6xx/r7xx const buffer support
  drm/radeon/kms: bump the version for r6xx/r7xx const buffer support
  drm/radeon/r6xx/r7xx: CS parser fixes
  drm/radeon/kms: fix some typos in r6xx/r7xx hpd setup
  ...

Fix up MSI-related conflicts in drivers/gpu/drm/radeon/radeon_irq_kms.c
2010-04-01 09:19:42 -07:00
Linus Torvalds
445c682b93 Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze
* 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze: (35 commits)
  microblaze: Support word copying in copy_tofrom_user
  microblaze: Print early printk information to log buffer
  microblaze: head.S typo fix
  microblaze: Use MICROBLAZE_TLB_SIZE in asm code
  microblaze: Kconfig Fix - pci
  microblaze: Adding likely macros
  microblaze: Add .type and .size to ASM functions
  microblaze: Fix TLB macros
  microblaze: Use instruction with delay slot
  microblaze: Remove additional resr and rear loading
  microblaze: Change register usage for ESR and EAR
  microblaze: Prepare work for optimization in exception code
  microblaze: Add DEBUG option
  microblaze: Support systems without lmb bram
  microblaze: uaccess: Sync strlen, strnlen, copy_to/from_user
  microblaze: uaccess: Unify __copy_tofrom_user
  microblaze: uaccess: Move functions to generic location
  microblaze: uaccess: Fix put_user for noMMU
  microblaze: uaccess: Fix get_user macro for noMMU
  microblaze: uaccess: fix clear_user for noMMU kernel
  ...
2010-04-01 09:14:20 -07:00
Linus Torvalds
c7681f4637 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86:
  eeepc-wmi: new driver for WMI based hotkeys on Eee PC laptops
  asus-laptop: fix warning in asus_handle_init
2010-04-01 09:13:57 -07:00
Oleg Nesterov
b95c35e76b oom: fix the unsafe usage of badness() in proc_oom_score()
proc_oom_score(task) has a reference to task_struct, but that is all.
If this task was already released before we take tasklist_lock

	- we can't use task->group_leader, it points to nowhere

	- it is not safe to call badness() even if this task is
	  ->group_leader, has_intersects_mems_allowed() assumes
	  it is safe to iterate over ->thread_group list.

	- even worse, badness() can hit ->signal == NULL

Add the pid_alive() check to ensure __unhash_process() was not called.

Also, use "task" instead of task->group_leader. badness() should return
the same result for any sub-thread. Currently this is not true, but
this should be changed anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-01 08:50:21 -07:00
Michal Simek
ca3865bae5 microblaze: Support word copying in copy_tofrom_user
Word copying is used only for aligned addresses.
Here is space for improving to use any better copying technique.
Look at memcpy implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:25 +02:00
Michal Simek
6059b3cbeb microblaze: Print early printk information to log buffer
If early printk console is not enabled then all messages
are written to log buffer.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:25 +02:00
Michal Simek
3f21893586 microblaze: head.S typo fix
I forget to change register name in comments.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:24 +02:00
Michal Simek
0691c97d74 microblaze: Use MICROBLAZE_TLB_SIZE in asm code
TLB size was hardcoded in asm code. This patch brings ability
to change TLB size only in one place. (mmu.h).

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:24 +02:00
Michal Simek
9373dd6ab1 microblaze: Kconfig Fix - pci
I forget to remove pci Kconfig option.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:24 +02:00
Michal Simek
78ebfa884b microblaze: Adding likely macros
On the base on GCOV analytics is helpful to add likely/unlikely
macros.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:24 +02:00
Michal Simek
13851966da microblaze: Add .type and .size to ASM functions
Cachegrind analysis need this fix to be able to log asm functions.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:24 +02:00
Michal Simek
e84452dd9f microblaze: Fix TLB macros
To be able to do trace TLB operations.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:24 +02:00
Michal Simek
3765d6958d microblaze: Use instruction with delay slot
Sync labels.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
bd1637d63e microblaze: Remove additional resr and rear loading
RESR and REAR uses the same regs in whole file.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
b175bcfe31 microblaze: Change register usage for ESR and EAR
This change synchronize register usage in code.
ESR = R4
EAR = R3

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
7a6bbdc930 microblaze: Prepare work for optimization in exception code
Any sync branch must follow mts instructions not mfs.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
708e7153d6 microblaze: Add DEBUG option
Disable debug option in asm code.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
ee68f1745e microblaze: Support systems without lmb bram
When the system has no lmb bram, main memory should be start from
zero because of microblaze vectors.

DTS fragment could look like:
	DDR2_SDRAM: memory@0 {
		device_type = "memory";
		reg = < 0x0 0x10000000 >;
	} ;

Then you have to setup CONFIG_KERNEL_BASE_ADDR=0 which caused
that kernel physical start address will be zero. On reset vector place
will be jump to 0x100 and on 0x100 starts kernel text.

You have to solve how to load the kernel before cpu starts.
Tested with XMD.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
89ae9753ae microblaze: uaccess: Sync strlen, strnlen, copy_to/from_user
Last sync.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:23 +02:00
Michal Simek
94804a9b3d microblaze: uaccess: Unify __copy_tofrom_user
Move to generic location.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:22 +02:00
Michal Simek
cca79120c2 microblaze: uaccess: Move functions to generic location
noMMU and MMU use them.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:22 +02:00
Michal Simek
ef4e277b5d microblaze: uaccess: Fix put_user for noMMU
Here is small regression on dhrystone tests and I think
that on all benchmarking tests. It is due to better checking
mechanism in put_user macro

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:22 +02:00
Michal Simek
3a6d77245e microblaze: uaccess: Fix get_user macro for noMMU
Use unified version.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:22 +02:00
Michal Simek
527bdb52d5 microblaze: uaccess: fix clear_user for noMMU kernel
Previous patches fixed only MMU version and this is the first
patch for noMMU kernel

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:21 +02:00
Michal Simek
40e11e3380 microblaze: uaccess: Fix strncpy_from_user function
Generic implementation for noMMU and MMU version

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:21 +02:00
Michal Simek
4270690bd4 microblaze: uaccess: fix copy_from_user macro
copy_from_user macro also use copy_tofrom_user function

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:21 +02:00
Michal Simek
cc5a428b7a microblaze: uaccess: copy_to_user unification
noMMU and MMU kernel will use copy copy_tofrom_user
asm implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:20 +02:00
Michal Simek
0dcb409de7 microblaze: uaccess: sync put/get/clear_user macros
Add macro description and resort.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:20 +02:00
Michal Simek
8b651aa4a7 microblaze: uaccess: fix put_user and get_user macros
Use FIXUP macros and resort them.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:20 +02:00
Michal Simek
c77a9c4bb7 microblaze: uaccess: fix __get_user_asm macro
It is used __FIXUP_SECTION and __EX_TABLE_SECTION macros.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:20 +02:00
Michal Simek
40b1156db0 microblaze: uaccess: fix clean user macro
This is the first patch which does uaccess unification.
I choosed to do several patches to be able to use bisect
in future if any fault happens.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:20 +02:00
Michal Simek
60a729f7bb microblaze: move noMMU __range_ok function to uaccess.h
The same noMMU and MMU functions should be placed in
one file.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:20 +02:00
Michal Simek
357bc3c928 microblaze: Move exception_table_entry upward
Just sort to be able remove whole block.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:19 +02:00
Michal Simek
40db083433 microblaze: Remove segment.h
I would like to use asm-generic uaccess.h where are segment
macros defined. This is just first step.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:19 +02:00
Michal Simek
4009819cf9 microblaze: Remove memset in free_init_pages
We don't need to do it.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:19 +02:00
Arun Bhanu
6fa114e0f1 microblaze: Makefile cleanups
If CONFIG_INITRAMFS_SOURCE is set, "scripts/gen_initramfs_list.sh"
checks if the cpio image exists. Remove the duplicate check from the
Makefile.

Remove the "clean-kernel" variable which is unused in the Makefile and
is not used by the Kbuild.

Signed-off-by: Arun Bhanu <arun@bhanu.net>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:19 +02:00
Arun Bhanu
8a8804f1ab microblaze: Fix Makefile to delete build generated files
'make clean' does not to delete the following build generated file:
	arch/microblaze/boot/linux.bin.ub

'make mrproper' does not to delete the following build generated files:
	arch/microblaze/boot/simpleImage.*

Fix the Makefile to delete these build generated files.

See [1] for a discussion on why simpleImage.* files are deleted with 'make
mrproper' and not with 'make clean'.
	[1] http://lkml.org/lkml/2010/3/12/96

Signed-off-by: Arun Bhanu <arun@bhanu.net>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:19 +02:00
Arun Bhanu
699d17bc14 microblaze: Add a missing single quote to make 'make help' happy
'make ARCH=microblaze help' fails with the following error due to a
missing single quote.

/bin/sh: -c: line 0: unexpected EOF while looking for matching `''
/bin/sh: -c: line 1: syntax error: unexpected end of file
make: *** [help] Error 2

Signed-off-by: Arun Bhanu <arun@bhanu.net>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:19 +02:00
Steven J. Magnani
0c4ec16b86 microblaze: Fix "kstack=" parsing
The "kstack=" command line parameter is not parsed correctly.
All proper values are interpreted as zero.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-01 08:38:18 +02:00
Dave Airlie
d668046c13 drm/radeon/kms: enable ACPI powermanagement mode on radeon gpus.
Some GPUs have an APM/ACPI PM mode selection switch and some BIOSes
set this to APM. We really want this in ACPI mode for Linux.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-01 12:50:46 +10:00
Dave Airlie
08a370fa75 drm/radeon/kms: rs400/480 should set common registers.
These GPUs should be setting these registers up also.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-01 12:50:28 +10:00