Commit Graph

496 Commits

Author SHA1 Message Date
Keshavamurthy Anil S
bf8d5c52c3 [PATCH] kprobes: increment kprobe missed count for multiprobes
When multiple probes are registered at the same address and if due to some
recursion (probe getting triggered within a probe handler), we skip calling
pre_handlers and just increment nmissed field.

The below patch make sure it walks the list for multiple probes case.
Without the below patch we get incorrect results of nmissed count for
multiple probe case.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:45 -08:00
Keshavamurthy Anil S
00d7c05ab1 [PATCH] kprobes: no probes on critical path
For Kprobes critical path is the path from debug break exception handler
till the control reaches kprobes exception code.  No probes can be
supported in this path as we will end up in recursion.

This patch prevents this by moving the below function to safe __kprobes
section onto which no probes can be inserted.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:45 -08:00
Pierre Ossman
7a4ae749a4 [PATCH] Add try_to_freeze to kauditd
kauditd was causing suspends to fail because it refused to freeze.  Adding
a try_to_freeze() to its sleep loop solves the issue.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Acked-by: Pavel Machek <pavel@suse.cz>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:43 -08:00
Keshavamurthy Anil S
adad0f331f [PATCH] kprobes: fix race in aggregate kprobe registration
When registering multiple kprobes at the same address, we leave a small
window where the kprobe hlist will not contain a reference to the
registered kprobe, leading to potentially, a system crash if the breakpoint
is hit on another processor.

Patch below now automically relpace the old kprobe with the new
kprobe from the hash list.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:43 -08:00
Matt Helsley
64123fd42c [PATCH] Add getnstimestamp function
There are several functions that might seem appropriate for a timestamp:

get_cycles()
current_kernel_time()
do_gettimeofday()
<read jiffies/jiffies_64>

Each has problems with combinations of SMP-safety, low resolution, and
monotonicity. This patch adds a new function that returns a monotonic SMP-safe
timestamp with nanosecond resolution where available.

Changes:
	Split timestamp into separate patch
	Moved to kernel/time.c
	Renamed to getnstimestamp
	Fixed unintended-pointer-arithmetic bug

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:42 -08:00
Srivatsa Vaddagiri
c3f5902325 [PATCH] Fix RCU race in access of nohz_cpu_mask
Accessing nohz_cpu_mask before incrementing rcp->cur is racy.  It can cause
tickless idle CPUs to be included in rsp->cpumask, which will extend
graceperiods unnecessarily.

Fix this race.  It has been tested using extensions to RCU torture module
that forces various CPUs to become idle.

Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:42 -08:00
Srivatsa Vaddagiri
89d46b8778 [PATCH] Fix bug in RCU torture test
While doing some test of RCU torture module, I hit a OOPS in rcu_do_batch,
which was trying to processes callback of a module that was just removed.
This is because we weren't waiting long enough for all callbacks to fire.

Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:42 -08:00
Dipankar Sarma
ab4720ec76 [PATCH] add rcu_barrier() synchronization point
This introduces a new interface - rcu_barrier() which waits until all
the RCUs queued until this call have been completed.

Reiser4 needs this, because we do more than just freeing memory object
in our RCU callback: we also remove it from the list hanging off
super-block.  This means, that before freeing reiser4-specific portion
of super-block (during umount) we have to wait until all pending RCU
callbacks are executed.

The only change of reiser4 made to the original patch, is exporting of
rcu_barrier().

Cc: Hans Reiser <reiser@namesys.com>
Cc: Vladimir V. Saveliev <vs@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:42 -08:00
Mao, Bibo
b3e55c727f [PATCH] Kprobes: Reference count the modules when probed on it
When a Kprobes are inserted/removed on a modules, the modules must be ref
counted so as not to allow to unload while probes are registered on that
module.

Without this patch, the probed module is free to unload, and when the
probing module unregister the probe, the kpobes code while trying to
replace the original instruction might crash.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Mao Bibo <bibo.mao@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12 08:57:41 -08:00
Pavel Machek
123d3c13e2 [PATCH] fix swsusp on machines not supporting S4
Fix swsusp on machines not supporting S4.  With recent changes, it is not
possible to trigger it using /sys filesystem.  Swsusp does not really need
any support from low-level code, it is possible to reboot or halt at the
end of suspend.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-29 19:47:03 -08:00
David Gibson
5bd0190bf3 [PATCH] Fix crash when ptrace poking hugepage areas
set_page_dirty() will not cope with being handed a page * which is part of
a compound page, but not the master page in that compound page.  This case
can occur via access_process_vm() if you attemp to write to another
process's hugepage memory area using ptrace() (causing an oops or hang).

This patch fixes the bug by only calling set_page_dirty() from
access_process_vm() if the page is not a compound page.  We already use a
similar fix in bio_set_pages_dirty() for the case of direct io to
hugepages.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-29 19:47:03 -08:00
Paul Jackson
8c4b8add83 [PATCH] cpuset fork locking fix
Move the cpuset_fork() call below the write_unlock_irq call in
kernel/fork.c copy_process().

Since the cpuset-dual-semaphore-locking-overhaul.patch, the cpuset_fork()
routine acquires task_lock(), so cannot be called while holding the
tasklist_lock for write.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:24 -08:00
Ben Collins
bce61dd49d [PATCH] Fix hardcoded cpu=0 in workqueue for per_cpu_ptr() calls
Tracked this down on an Ultra Enterprise 3000.  It's a 6-way machine.  Odd
thing about this machine (and it's good for finding bugs like this) is that
the CPU id's are not 0 based.  For instance, on my machine the CPU's are
6/7/10/11/14/15.

This caused some NULL pointer dereference in kernel/workqueue.c because for
single_threaded workqueue's, it hardcoded the cpu to 0.

I changed the 0's to any_online_cpu(cpu_online_mask), which cpumask.h
claims is "First cpu in mask".  So this fits the same usage.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:23 -08:00
Oleg Nesterov
ee500f2749 [PATCH] fix 32bit overflow in timespec_to_sample()
fix 32bit overflow in timespec_to_sample()

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:23 -08:00
Andrew Morton
c13cf856cb [PATCH] fork.c: proc_fork_connector() called under write_lock()
Don't do that - it does GFP_KERNEL allocations, for a start.

(Reported by Guillaume Thouvenin <guillaume.thouvenin@bull.net>)

Acked-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:23 -08:00
Ashok Raj
a9d9baa1e8 [PATCH] clean up lock_cpu_hotplug() in cpufreq
There are some callers in cpufreq hotplug notify path that the lowest
function calls lock_cpu_hotplug().  The lock is already held during
cpu_up() and cpu_down() calls when the notify calls are broadcast to
registered clients.

Ideally if possible, we could disable_preempt() at the highest caller and
make sure we dont sleep in the path down in cpufreq->driver_target() calls
but the calls are so intertwined and cumbersome to cleanup.

Hence we consistently use lock_cpu_hotplug() and unlock_cpu_hotplug() in
all places.

 - Removed export of cpucontrol semaphore and made it static.
 - removed explicit uses of up/down with lock_cpu_hotplug()
   so we can keep track of the the callers in same thread context and
   just keep refcounts without calling a down() that causes a deadlock.
 - Removed current_in_hotplug() uses
 - Removed PF_HOTPLUG_CPU in sched.h introduced for the current_in_hotplug()
   temporary workaround.

Tested with insmod of cpufreq_stat.ko, and logical online/offline
to make sure we dont have any hang situations.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: Zwane Mwaikambo <zwane@linuxpower.ca>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:23 -08:00
Benjamin Herrenschmidt
e9b15b54d3 [PATCH] Fix crash in unregister_console()
If unregister_console() is inadvertently called while no consoles are
registered, it will crash trying to dereference NULL pointer.  It is
necessary to fix that because register_console() provides no indication
that it actually registered the console passed in.  In fact, it may well
decide not to register it based on various things...

(akpm: It'd be better to make register_console() return something and fix the
callers.  All 106 of them...)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-23 16:08:39 -08:00
Hugh Dickins
cc3327e7df [PATCH] mm: unbloat get_futex_key
The follow_page changes in get_futex_key have left it with two almost
identical blocks, when handling the rare case of a futex in a nonlinear vma.
get_user_pages will itself do that follow_page, and its additional
find_extend_vma is hardly any overhead since the vma is already cached.  Let's
just delete the follow_page block and let get_user_pages do it.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-23 16:08:38 -08:00
Matthew Wilcox
c2b5a251b9 [PATCH] Check the irq number is within bounds
Most of the functions already check. Do the ones that didn't.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-23 11:11:28 -08:00
Hugh Dickins
0b0db14c53 [PATCH] unpaged: copy_page_range vma
For copy_one_pte's print_bad_pte to show the task correctly (instead of
"???"), dup_mmap must pass down parent vma rather than child vma.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-22 09:13:43 -08:00
Paul E. McKenney
996417d2c4 [PATCH] add success/failure indication to RCU torture test
One issue with the RCU torture test is that the current error flagging can
be lost in dmesg.  This patch adds a "SUCCESS"/"FAILURE" string to the line
that flags the end of the test, where it can easily be seen with "dmesg |
tail" at the end of the test.  Also adds tests of architecture-specific
memory barriers -- or, more likely, of the RCU torture test itself.

Cc: <vatsa@in.ibm.com>
Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-18 07:49:45 -08:00
Martin Waitz
ddad86c2d6 [PATCH] DocBook: include printk documentation
Add printk documentation to kernel-api.

Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:21 -08:00
George Anzinger
3f39894d1b [PATCH] timespec: normalize off by one errors
It would appear that the timespec normalize code has an off by one error.
Found in three places.  Thanks to Ben for spotting.

Signed-off-by: George Anzinger<george@mvista.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:17 -08:00
Zach Brown
20dcae3243 [PATCH] aio: remove kioctx from mm_struct
Sync iocbs have a life cycle that don't need a kioctx.  Their retrying, if
any, is done in the context of their owner who has allocated them on the
stack.

The sole user of a sync iocb's ctx reference was aio_complete() checking for
an elevated iocb ref count that could never happen.  No path which grabs an
iocb ref has access to sync iocbs.

If we were to implement sync iocb cancelation it would be done by the owner of
the iocb using its on-stack reference.

Removing this chunk from aio_complete allows us to remove the entire kioctx
instance from mm_struct, reducing its size by a third.  On a i386 testing box
the slab size went from 768 to 504 bytes and from 5 to 8 per page.

Signed-off-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:16 -08:00
Kirill Korotaev
4557398f8c [PATCH] stop_machine() vs. synchronous IPI send deadlock
This fixes deadlock of stop_machine() vs.  synchronous IPI send.  The
problem is that stop_machine() disables interrupts before disabling
preemption on other CPUs.  So if another CPU is preempted and then calls
something like flush_tlb_all() it will deadlock with CPU doing
stop_machine() and which can't process IPI due to disabled IRQs.

I changed stop_machine() to do the same things exactly as it does on other
CPUs, i.e.  it should disable preemption first on _all_ CPUs including
itself and only after that disable IRQs.

Signed-off-by: Kirill Korotaev <dev@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Andrey Savochkin" <saw@sawoct.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:16 -08:00
Ingo Molnar
dbdf65b1b7 [PATCH] rcutorture: renice to low priority
Make the box usable for interactive work when running the RCU torture test,
by renicing the RCU torture-test threads to +19 by default.  Kthreads run
at nice -5 by default.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:15 -08:00
Heiko Carstens
b17b0421d7 [PATCH] signal handling: revert sigkill priority fix
This patch reverts commit c33880aadd since
it's not needed anymore. As pointed out by Roland McGrath the real fix
is to deliver all signals before returning to user space.
See http://www.ussg.iu.edu/hypermail/linux/kernel/0509.2/0683.html
A fix for s390 has been merged.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:15 -08:00
Al Viro
10ebffde3d [PATCH] m68k: introduce setup_thread_stack() and end_of_stack()
encapsulates the rest of arch-dependent operations with thread_info access.
Two new helpers - setup_thread_stack() and end_of_stack().  For normal case
the former consists of copying thread_info of parent to new thread_info and
the latter returns pointer immediately past the end of thread_info.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:13 -08:00
Al Viro
a1261f5461 [PATCH] m68k: introduce task_thread_info
new helper - task_thread_info(task).  On platforms that have thread_info
allocated separately (i.e.  in default case) it simply returns
task->thread_info.  m68k wants (and for good reasons) to embed its thread_info
into task_struct.  So it will (in later patch) have task_thread_info() of its
own.  For now we just add a macro for generic case and convert existing
instances of its body in core kernel to uses of new macro.  Obviously safe -
all normal architectures get the same preprocessor output they used to get.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:13 -08:00
Bob Picco
5563e77078 [PATCH] cpuset: fix return without releasing semaphore
It is wrong to acquire the semaphore and then return from
cpuset_zone_allowed without releasing it.

Signed-off-by: Bob Picco <bob.picco@hp.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:11 -08:00
Christoph Hellwig
005f18dfd0 [PATCH] fix task_struct leak in ptrace
When ptrace_attach fails we need to drop the task_struct reference.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:11 -08:00
Jeff Garzik
bca73e4bf8 [PATCH] move pm_register/etc. to CONFIG_PM_LEGACY, pm_legacy.h
Since few people need the support anymore, this moves the legacy
pm_xxx functions to CONFIG_PM_LEGACY, and include/linux/pm_legacy.h.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:10 -08:00
David S. Miller
393b072587 [SPARC64]: Re-export uts_sem for solaris compat module.
Revert: b26b9bc582

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 12:47:50 -08:00
Oleg Nesterov
7ed0175a46 [PATCH] Don't auto-reap traced children
If a task is being traced we never auto-reap it even if it might look
like its parent doesn't care. The tracer obviously _does_ care.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-10 09:57:19 -08:00
Chen, Kenneth W
a47ab9371e [PATCH] optimize activate_task()
recalc_task_prio() is called from activate_task() to calculate dynamic
priority and interactive credit for the activating task.  For real-time
scheduling process, all that dynamic calculation is thrown away at the end
because rt priority is fixed.  Patch to optimize recalc_task_prio() away
for rt processes.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <piggin@cyberone.com.au>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 16:07:44 -08:00
Linus Torvalds
28d838cc4d Fix ptrace self-attach rule
Before we did CLONE_THREAD, the way to check whether we were attaching
to ourselves was to just check "current == task", but with CLONE_THREAD
we should check that the thread group ID matches instead.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 11:33:07 -08:00
Nick Piggin
64c7c8f885 [PATCH] sched: resched and cpu_idle rework
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid.  Improves efficiency of
resched_task and some cpu_idle routines.

* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
  and as we hold it during resched_task, then there is no need for an
  atomic test and set there. The only other time this should be set is
  when the task's quantum expires, in the timer interrupt - this is
  protected against because the rq lock is irq-safe.

- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
  won't get unset until the task get's schedule()d off.

- If we are running on the same CPU as the task we resched, then set
  TIF_NEED_RESCHED and no further action is required.

- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
  after TIF_NEED_RESCHED has been set, then we need to send an IPI.

Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.

* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
  becomes true, explicitly call schedule(). This makes things a bit clearer
  (IMO), but haven't updated all architectures yet.

- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
  to the resched_task rules, this isn't needed (and actually breaks the
  assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
  held). So remove that. Generally one less locked memory op when switching
  to the idle thread.

- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
  most polling idle loops. The above resched_task semantics allow it to be
  set until before the last time need_resched() is checked before going into
  a halt requiring interrupt wakeup.

  Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
  can be always left set, completely eliminating resched IPIs when rescheduling
  the idle task.

  POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:33 -08:00
Con Kolivas
ede3d0fba9 [PATCH] sched: consider migration thread with smp nice
The intermittent scheduling of the migration thread at ultra high priority
makes the smp nice handling see that runqueue as being heavily loaded.  The
migration thread itself actually handles the balancing so its influence on
priority balancing should be ignored.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:32 -08:00
Con Kolivas
6dd4a85bb3 [PATCH] sched: correct smp_nice_bias
The priority biasing was off by mutliplying the total load by the total
priority bias and this ruins the ratio of loads between runqueues. This
patch should correct the ratios of loads between runqueues to be proportional
to overall load. -2nd attempt.

From: Dave Kleikamp <shaggy@austin.ibm.com>

  This patch fixes a divide-by-zero error that I hit on a two-way i386
  machine.  rq->nr_running is tested to be non-zero, but may change by the
  time it is used in the division.  Saving the value to a local variable
  ensures that the same value that is checked is used in the division.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:32 -08:00
Con Kolivas
3b0bd9bc6f [PATCH] sched: smp nice bias busy queues on idle rebalance
To intensify the 'nice' support across physical cpus on SMP we can bias the
loads on idle rebalancing. To prevent idle rebalance from trying to pull tasks
from queues that appear heavily loaded we only bias the load if there is more
than one task running.

Add some minor micro-optimisations and have only one return from __source_load
and __target_load functions.

Fix the fact that target_load was not biased by priority when type == 0.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:32 -08:00
Con Kolivas
dad1c65c80 [PATCH] sched: account rt tasks in prio_bias()
Real time tasks' effect on prio_bias should be based on their real time
priority level instead of their static_prio which is based on nice.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:32 -08:00
Con Kolivas
738a2ccbcf [PATCH] sched: change prio bias only if queued
prio_bias should only be adjusted in set_user_nice if p is actually currently
queued.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:32 -08:00
Con Kolivas
b910472dd3 [PATCH] sched: implement nice support across physical cpus on SMP
This patch implements 'nice' support across physical cpus on SMP.

It introduces an extra runqueue variable prio_bias which is the sum of the
(inverted) static priorities of all the tasks on the runqueue.

This is then used to bias busy rebalancing between runqueues to obtain good
distribution of tasks of different nice values.  By biasing the balancing only
during busy rebalancing we can avoid having any significant loss of throughput
by not affecting the carefully tuned idle balancing already in place.  If all
tasks are running at the same nice level this code should also have minimal
effect.  The code is optimised out in the !CONFIG_SMP case.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:32 -08:00
Rafael J. Wysocki
0fbeb5a45d [PATCH] swsusp: rework swsusp_suspend
This patch makes only the functions in swsusp.c call functions in snapshot.c
and not both ways.   It also moves the check for available swap out of
swsusp_suspend() which is necessary for separating the swap-handling functions
in swsusp from the core code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:52 -08:00
Rafael J. Wysocki
ed14b52701 [PATCH] swsusp: simplify pagedir relocation
This patch simplifies the relocation of the page backup list (aka pagedir)
during resume.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:52 -08:00
Rafael J. Wysocki
054bd4c188 [PATCH] swsusp: reduce code duplication
The changes made by this patch are necessary for the pagedir relocation
simplification in the next patch.   Additionally, these changes allow us to
drop check_pagedir() and make get_safe_page() be a one-line wrapper around
alloc_image_page() (get_safe_page() goes to snapshot.c, because
alloc_image_page() is static and it does not make sense to export it).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:52 -08:00
Pavel Machek
969e9afd48 [PATCH] sleep: Fix oops in enter_state
If ACPI sleep is not configured, but someone still wants to run swsusp,
he'd get oops in enter_state.  This is regression since 2.6.14 and this
fixes it.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:50 -08:00
Anton Blanchard
3aef1bde14 [PATCH] quieten softlockup at boot
On a large SMP box we get a lot of softlockup thread XX started lines.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:50 -08:00
Ashok Raj
90d45d17f3 [PATCH] cpu hotplug: fix locking in cpufreq drivers
When calling target drivers to set frequency, we take cpucontrol lock.
When we modified the code to accomodate CPU hotplug, there was an attempt
to take a double lock of cpucontrol leading to a deadlock.  Since the
current thread context is already holding the cpucontrol lock, we dont need
to make another attempt to acquire it.

Now we leave a trace in current->flags indicating current thread already is
under cpucontrol lock held, so we dont attempt to do this another time.

Thanks to Andrew Morton for the beating:-)

From: Brice Goglin <Brice.Goglin@ens-lyon.org>

  Build fix

(akpm: this patch is still unpleasant.  Ashok continues to look for a cleaner
solution, doesn't he?  ;))

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:50 -08:00
Al Viro
330d57fb98 [PATCH] Fix sysctl unregistration oops (CVE-2005-2709)
You could open the /proc/sys/net/ipv4/conf/<if>/<whatever> file, then
wait for interface to go away, try to grab as much memory as possible in
hope to hit the (kfreed) ctl_table.  Then fill it with pointers to your
function.  Then do read from file you've opened and if you are lucky,
you'll get it called as ->proc_handler() in kernel mode.

So this is at least an Oops and possibly more.  It does depend on an
interface going away though, so less of a security risk than it would
otherwise be.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08 17:57:30 -08:00