Build issues were mostly in the ACPI=n case -- don't do that.
Select ACPI from IA64_GENERIC.
Add some missing dependencies on ACPI.

Mark BLACKLIST_YEAR and some laptop-only ACPI drivers
as X86-only.  Let me know when you get an IA64 Laptop.
Signed-off-by: NLen Brown <len.brown@intel.com>

With CONFIG_PREEMPT && !CONFIG_SMP, it's possible for sys_getppid to
return a bogus value if the parent's task_struct gets reallocated after
current->group_leader->real_parent is read:

        asmlinkage long sys_getppid(void)
        {
                int pid;
                struct task_struct *me = current;
                struct task_struct *parent;

                parent = me->group_leader->real_parent;
RACE HERE =>    for (;;) {
                        pid = parent->tgid;
        #ifdef CONFIG_SMP
        {
                        struct task_struct *old = parent;

                        /*
                         * Make sure we read the pid before re-reading the
                         * parent pointer:
                         */
                        smp_rmb();
                        parent = me->group_leader->real_parent;
                        if (old != parent)
                                continue;
        }
        #endif
                        break;
                }
                return pid;
        }

If the process gets preempted at the indicated point, the parent process
can go ahead and call exit() and then get wait()'d on to reap its
task_struct. When the preempted process gets resumed, it will not do any
further checks of the parent pointer on !CONFIG_SMP: it will read the
bad pid and return.

So, the same algorithm used when SMP is enabled should be used when
preempt is enabled, which will recheck ->real_parent in this case.
Signed-off-by: NDavid Meybohm <dmeybohmlkml@bellsouth.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As suggested by Michael Kerrisk <mtk-manpages@gmx.net>, make RLIMIT_NICE
consistent with getpriority before it becomes available in released glibc.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NChris Wright <chrisw@osdl.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This bug is quite subtle and only happens in a very interesting
situation where a real-time threaded process is in the middle of a
coredump when someone whacks it with a SIGKILL.  However, this deadlock
leaves the system pretty hosed and you have to reboot to recover.

Not good for real-time priority-preemption applications like our
telephony application, with 90+ real-time (SCHED_FIFO and SCHED_RR)
processes, many of them multi-threaded, interacting with each other for
high volume call processing.
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We have a chek in there to make sure that the name won't overflow
task_struct.comm[], but it's triggering for scsi with lots of HBAs, only
scsi is using single-threaded workqueues which don't append the "/%d"
anyway.

All too hard.  Just kill the BUG_ON.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

[ kthread_create() uses vsnprintf() and limits the thing, so no
  actual overflow can actually happen regardless ]
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix possible cpuset_sem ABBA deadlock if 'notify_on_release' set.

For a particular usage pattern, creating and destroying cpusets fairly
frequently using notify_on_release, on a very large system, this deadlock
can be seen every few days.  If you are not using the cpuset
notify_on_release feature, you will never see this deadlock.

The existing code, on task exit (or cpuset deletion) did:

  get cpuset_sem
  if cpuset marked notify_on_release and is ready to release:
    compute cpuset path relative to /dev/cpuset mount point
    call_usermodehelper() forks /sbin/cpuset_release_agent with path
  drop cpuset_sem

Unfortunately, the fork in call_usermodehelper can allocate memory, and
allocating memory can require cpuset_sem, if the mems_generation values
changed in the interim.  This results in an ABBA deadlock, trying to obtain
cpuset_sem when it is already held by the current task.

To fix this, I put the cpuset path (which must be computed while holding
cpuset_sem) in a temporary buffer, to be used in the call_usermodehelper
call of /sbin/cpuset_release_agent only _after_ dropping cpuset_sem.

So the new logic is:

  get cpuset_sem
  if cpuset marked notify_on_release and is ready to release:
    compute cpuset path relative to /dev/cpuset mount point
    stash path in kmalloc'd buffer
  drop cpuset_sem
  call_usermodehelper() forks /sbin/cpuset_release_agent with path
  free path

The sharp eyed reader might notice that this patch does not contain any
calls to kmalloc.  The existing code in the check_for_release() routine was
already kmalloc'ing a buffer to hold the cpuset path.  In the old code, it
just held the buffer for a few lines, over the cpuset_release_agent() call
that in turn invoked call_usermodehelper().  In the new code, with the
application of this patch, it returns that buffer via the new char
**ppathbuf parameter, for later use and freeing in cpuset_release_agent(),
which is called after cpuset_sem is dropped.  Whereas the old code has just
one call to cpuset_release_agent(), right in the check_for_release()
routine, the new code has three calls to cpuset_release_agent(), from the
various places that a cpuset can be released.

This patch has been build and booted on SN2, and passed a stress test that
previously hit the deadlock within a few seconds.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Revert this June 17 patch: it broke persistence of timers across execve().

Cc: Roland McGrath <roland@redhat.com>
Cc: george anzinger <george@mvista.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This removes the calls to device_suspend() from the shutdown path that
were added sometime during 2.6.13-rc*.  They aren't working properly on
a number of configs (I got reports from both ppc powerbook users and x86
users) causing the system to not shutdown anymore.

I think it isn't the right approach at the moment anyway.  We have
already a shutdown() callback for the drivers that actually care about
shutdown and the suspend() code isn't yet in a good enough shape to be
so much generalized.  Also, the semantics of suspend and shutdown are
slightly different on a number of setups and the way this was patched in
provides little way for drivers to cleanly differenciate.  It should
have been at least a different message.

For 2.6.13, I think we should revert to 2.6.12 behaviour and have a
working suspend back.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The module code assumes noone will ever ask for a per-cpu area more than
SMP_CACHE_BYTES aligned.  However, as these cases show, gcc asks sometimes
asks for 32-byte alignment for the per-cpu section on a module, and if
CONFIG_X86_L1_CACHE_SHIFT is 4, we hit that BUG_ON().  This is obviously an
unusual combination, as there have been few reports, but better to warn
than die.

See:
	http://www.ussg.iu.edu/hypermail/linux/kernel/0409.0/0768.html

And more recently:
	http://bugs.gentoo.org/show_bug.cgi?id=97006Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This removes sys_set_zone_reclaim() for now.  While i'm sure Martin is
trying to solve a real problem, we must not hard-code an incomplete and
insufficient approach into a syscall, because syscalls are pretty much
for eternity.  I am quite strongly convinced that this syscall must not
hit v2.6.13 in its current form.

Firstly, the syscall lacks basic syscall design: e.g. it allows the
global setting of VM policy for unprivileged users. (!) [ Imagine an
Oracle installation and a SAP installation on the same NUMA box fighting
over the 'optimal' setting for this flag. What will they do? Will they
try to set the flag to their own preferred value every second or so? ]

Secondly, it was added based on a single datapoint from Martin:

 http://marc.theaimsgroup.com/?l=linux-mm&m=111763597218177&w=2

where Martin characterizes the numbers the following way:

 ' Run-to-run variability for "make -j" is huge, so these numbers aren't
   terribly useful except to see that with reclaim the benchmark still
   finishes in a reasonable amount of time. '

in other words: the fundamental problem has likely not been solved, only
a tendential move into the right direction has been observed, and a
handful of numbers were picked out of a set of hugely variable results,
without showing the variability data. How much variance is there
run-to-run?

I'd really suggest to first walk the walk and see what's needed to get
stable & predictable kernel compilation numbers on that NUMA box, before
adding random syscalls to tune a particular aspect of the VM ... which
approach might not even matter once the whole picture has been analyzed
and understood!

The third, most important point is that the syscall exposes VM tuning
internals in a completely unstructured way. What sense does it make to
have a _GLOBAL_ per-node setting for 'should we go to another node for
reclaim'? If then it might make sense to do this per-app, via numalib or
so.

The change is minimalistic in that it doesnt remove the syscall and the
underlying infrastructure changes, only the user-visible changes.  We
could perhaps add a CAP_SYS_ADMIN-only sysctl for this hack, a'ka
/proc/sys/vm/swappiness, but even that looks quite counterproductive
when the generic approach is that we are trying to reduce the number of
external factors in the VM balance picture.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This snuck in with an x86_64 change.  Thanks to Richard Purdie
<rpurdie@rpsys.net> for spotting it.

Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If device_suspend(PMSG_FREEZE) is not ready to be called in
kernel_restart it is definitely not ready to be called in the even more
fickle kernel_kexec.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

(We found this (after a customer complained) and it is in the kernel.org
kernel.  Seems that for CLOCK_MONOTONIC absolute timers and clock_nanosleep
calls both the request time and wall_to_monotonic are subtracted prior to
the normalize resulting in an overflow in the existing normalize test.
This causes the result to be shifted ~4 seconds ahead instead of ~2 seconds
back in time.)

The normalize code in posix-timers.c fails when the tv_nsec member is ~1.2
seconds negative.  This can happen on absolute timers (and
clock_nanosleeps) requested on CLOCK_MONOTONIC (both the request time and
wall_to_monotonic are subtracted resulting in the possibility of a number
close to -2 seconds.)

This fix uses the set_normalized_timespec() (which does not have an
overflow problem) to fix the problem and as a side effect makes the code
cleaner.
Signed-off-by: NGeorge Anzinger <george@mvista.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This avoids some potential stack overflows with very deep softirq callchains.
i386 does this too.

TOADD CFI annotation
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

My fairly ordinary x86 test box gets stuck during reboot on the
wait_for_completion() in ide_do_drive_cmd():
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

`gcc -W' likes to complain if the static keyword is not at the beginning of
the declaration.  This patch fixes all remaining occurrences of "inline
static" up with "static inline" in the entire kernel tree (140 occurrences in
47 files).

While making this change I came across a few lines with trailing whitespace
that I also fixed up, I have also added or removed a blank line or two here
and there, but there are no functional changes in the patch.
Signed-off-by: NJesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add kerneldoc to kernel/crash_dump.c
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add kerneldoc to kernel/cpuset.c

Fix cpuset typos in init/Kconfig
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add kerneldoc to kernel/capability.c
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Split spin lock and r/w lock implementation into a single try which is done
inline and an out of line function that repeatedly tries to get the lock
before doing the cpu_relax().  Add a system control to set the number of
retries before a cpu is yielded.

The reason for the spin lock retry is that the diagnose 0x44 that is used to
give up the virtual cpu is quite expensive.  For spin locks that are held only
for a short period of time the costs of the diagnoses outweights the savings
for spin locks that are held for a longer timer.  The default retry count is
1000.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the recent off-by-one fix in the itimer code:

1. The repeating timer is figured using the requested time
	(not +1 as we know where we are in the jiffie).

2. The tests for interval too large are left to the time_val to jiffie code.
Signed-off-by: NGeorge Anzinger <george@mvista.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch fixes a warning in the disable_nonboot_cpus call in
kernel/power/smp.c.

Signed-off by: Nigel Cunningham <nigel@suspend2.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Here's the patch again to fix the code to handle if the values between
MAX_USER_RT_PRIO and MAX_RT_PRIO are different.

Without this patch, an SMP system will crash if the values are
different.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NDean Nelson <dcn@sgi.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

RLIMIT_RTPRIO is supposed to grant non privileged users the right to use
SCHED_FIFO/SCHED_RR scheduling policies with priorites bounded by the
RLIMIT_RTPRIO value via sched_setscheduler(). This is usually used by
audio users.

Unfortunately this is broken in 2.6.13rc3 as you can see in the excerpt
from sched_setscheduler below:

        /*
         * Allow unprivileged RT tasks to decrease priority:
         */
        if (!capable(CAP_SYS_NICE)) {
                /* can't change policy */
                if (policy != p->policy)
                        return -EPERM;

After the above unconditional test which causes sched_setscheduler to
fail with no regard to the RLIMIT_RTPRIO value the following check is made:

               /* can't increase priority */
                if (policy != SCHED_NORMAL &&
                    param->sched_priority > p->rt_priority &&
                    param->sched_priority >
                                p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
                        return -EPERM;

Thus I do believe that the RLIMIT_RTPRIO value must be taken into
account for the policy check, especially as the RLIMIT_RTPRIO limit is
of no use without this change.

The attached patch fixes this problem.
Signed-off-by: NAndreas Steinmetz <ast@domdv.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The suspend to disk code was a poor copy of the code in
sys_reboot now that we have kernel_power_off, kernel_restart
and kernel_halt use them instead of poorly duplicating them inline.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We know the system is in trouble so there is no question if this
is an emergecy :)
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We already do all of the gymnastics to run from process context
to call the power off code so call into the power off code cleanly.

This especially helps acpi as part of it's shutdown logic should
run acpi_shutdown called from device_shutdown which was not
being called from here.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When the kernel is working well and we want to restart cleanly
kernel_restart is the function to use.   But in many instances
the kernel wants to reboot when thing are expected to be working
very badly such as from panic or a software watchdog handler.

This patch adds the function emergency_restart() so that
callers can be clear what semantics they expect when calling
restart.  emergency_restart() is expected to be callable
from interrupt context and possibly reliable in even more
trying circumstances.

This is an initial generic implementation for all architectures.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It is obvious we wanted to call kernel_restart here
but since we don't have it the code was expanded inline and hasn't
been correct since sometime in 2.4.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Because the factors of sys_reboot don't exist people calling
into the reboot path duplicate the code badly, leading to
inconsistent expectations of code in the reboot path.

This patch should is just code motion.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the recent addition of device_suspend calls into
sys_reboot two code paths were missed.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This moves the inotify sysctl knobs to "/proc/sys/fs/inotify" from
"/proc/sys/fs".  Also some related cleanup.
Signed-off-by: NRobert Love <rml@novell.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:

        * dnotify requires the opening of one fd per each directory
          that you intend to watch. This quickly results in too many
          open files and pins removable media, preventing unmount.
        * dnotify is directory-based. You only learn about changes to
          directories. Sure, a change to a file in a directory affects
          the directory, but you are then forced to keep a cache of
          stat structures.
        * dnotify's interface to user-space is awful.  Signals?

inotify provides a more usable, simple, powerful solution to file change
notification:

        * inotify's interface is a system call that returns a fd, not SIGIO.
	  You get a single fd, which is select()-able.
        * inotify has an event that says "the filesystem that the item
          you were watching is on was unmounted."
        * inotify can watch directories or files.

Inotify is currently used by Beagle (a desktop search infrastructure),
Gamin (a FAM replacement), and other projects.

See Documentation/filesystems/inotify.txt.
Signed-off-by: NRobert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

dup_mmap of a VM_DONTCOPY vma forgot to lower the child's total_vm.  (But
no way does this account for the recent report of total_vm seen too low.)
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/power/disk.c needs a declaration of name_to_dev_t() in scope.  mount.h
seems like an appropriate choice.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Free some RAM before entering S3 so that upon
resume we can be sure early allocations will succeed.

http://bugzilla.kernel.org/show_bug.cgi?id=3469Signed-off-by: NDavid Shaohua Li <shaohua.li@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Register an "acpi" system device to be notified of shutdown preparation.
This depends on CONFIG_PM

http://bugzilla.kernel.org/show_bug.cgi?id=4041Signed-off-by: NAlexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

The BKS might be reacquired before we have dropped PREEMPT_ACTIVE, which
could trigger a second could trigger a second cond_resched() call.  Bug
found by Hirofumi Ogawa.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a new section called ".data.read_mostly" for data items that are read
frequently and rarely written to like cpumaps etc.

If these maps are placed in the .data section then these frequenly read
items may end up in cachelines with data is is frequently updated.  In that
case all processors in an SMP system must needlessly reload the cachelines
again and again containing elements of those frequently used variables.

The ability to share these cachelines will allow each cpu in an SMP system
to keep local copies of those shared cachelines thereby optimizing
performance.
Signed-off-by: NAlok N Kataria <alokk@calsoftinc.com>
Signed-off-by: NShobhit Dayal <shobhit@calsoftinc.com>
Signed-off-by: NChristoph Lameter <christoph@scalex86.org>
Signed-off-by: NShai Fultheim <shai@scalex86.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

freezeable() already tests for TRACED/STOPPED processes, no need to do it
twice.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>