linux-toradex.git/arch/avr32/kernel/process.c, branch v2.6.35-rc3

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

ptrace: remove PT_DTRACE from avr32, mn10300, parisc, s390, sh, xtensa

2009-06-18T20:03:48+00:00

avr32, mn10300, parisc, s390, sh, xtensa:

They never set PT_DTRACE, but clear it after do_execve().

Signed-off-by: Oleg Nesterov 
Cc: David Howells 
Acked-by: Kyle McMartin 
Cc: Grant Grundler 
Cc: Matthew Wilcox 
Acked-by: Martin Schwidefsky 
Cc: Heiko Carstens 
Acked-by: Paul Mundt 
Acked-by: Chris Zankel 
Acked-by: Roland McGrath 
Acked-by: Haavard Skinnemoen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Simplify copy_thread()

2009-04-03T02:04:51+00:00

First argument unused since 2.3.11.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

avr32: Introducing asm/syscalls.h

2008-12-17T12:32:38+00:00

Declaring arch-dependent syscalls for avr32 architecture

Signed-off-by: Jaswinder Singh 
Signed-off-by: Haavard Skinnemoen

avr32: Minor pm_power_off cleanup

2008-10-08T16:44:58+00:00

Include  to see the declaration of pm_power_off, and remove
unneeded NULL initializer.

Signed-off-by: Haavard Skinnemoen

avr32: Use instead of

2008-08-05T12:36:57+00:00

Update all avr32-specific files to use the new platform-specific header
locations. Drivers shared with ARM are left alone for now.

Signed-off-by: Haavard Skinnemoen

nohz: prevent tick stop outside of the idle loop

2008-07-18T16:10:28+00:00

Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:

	scheduler switch to idle task
	enable interrupts

Window starts here

	----> interrupt happens (does not set NEED_RESCHED)
	      	irq_exit() stops the tick

	----> interrupt happens (does set NEED_RESCHED)

	return from schedule()
	
	cpu_idle(): preempt_disable();

Window ends here

The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.

The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.

Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.

cpu_idle()
{
	preempt_disable();

	while(1) {
		 tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
		 			          are in the idle loop

		 while (!need_resched())
		       halt();

		 tick_nohz_restart_sched_tick(); <- disables NOHZ mode
		 preempt_enable_no_resched();
		 schedule();
		 preempt_disable();
	}
}

In hindsight we should have done this forever, but ... 

/me grabs a large brown paperbag.

Debugged-by: Jack Ren , 
Debugged-by: eric miao 
Signed-off-by: Thomas Gleixner

avr32: Add hardware power-down function call

2008-04-20T00:40:11+00:00

This patch adds in the indirect call to pm_power_off(), as is done in
other architectures (e.g. ARM).

Tested on NGW100, with custom board with GPIO control over main DC
power.

Signed-off-by: Peter Ma 
Signed-off-by: Haavard Skinnemoen

avr32: Move sleep code into mach-at32ap

2008-04-20T00:40:07+00:00

Create a new file, pm-at32ap700x.S, in mach-at32ap and move the CPU
idle sleep code there. Make it possible to disable the sleep code.

Signed-off-by: Haavard Skinnemoen

avr32: Fix OCD refcounting bug

2008-02-27T13:23:53+00:00

Iff the parent has TIF_DEBUG set, _and_ clone_flags includes
CLONE_PTRACE we should set the TIF_DEBUG flag for the child and
increment the ocd refcount. Otherwise, the TIF_DEBUG flag must be
unset.

Currently, the child inherits TIF_DEBUG from the parent before
copy_thread is called, so TIF_DEBUG may be already be set before we
determine whether the child is supposed to inherit debugging
capabilities from the parent or not. This means that ocd_enable()
won't increment the refcount, because TIF_DEBUG is already set, and
that TIF_DEBUG will be set for processes that aren't being debugged.

This leads to a refcounting asymmetry, which may show up as

------------[ cut here ]------------
Badness at arch/avr32/kernel/ocd.c:73
PC is at ocd_disable+0x34/0x60
LR is at put_lock_stats+0xa/0x20

as reported by David Brownell. Happens when strace'ing a process that
forks a new child process, e.g. "strace mount -tjffs2 mtd1 /mnt", and
subsequently killing the child process (e.g. "umount /mnt".)

Signed-off-by: Haavard Skinnemoen