In arch/ia64/kernel/ptrace.c there is a test for a peek or poke of a
register image (in register backing storage).
The test can be unnecessarily long (and occurs while holding the tasklist_lock).
Especially long on a large system with thousands of active tasks.

The ptrace caller (presumably a debugger) specifies the pid of
its target and an address to peek or poke.  But the debugger could be
attached to several tasks.
The idea of find_thread_for_addr() is to find whether the target address
is in the RBS for any of those tasks.

Currently it searches the thread-list of the target pid.  If that search
does not find a match, and the shared mm-struct's user count indicates
that there are other tasks sharing this address space (a rare occurrence),
a search is made of all the tasks in the system.

Another approach can drastically shorten this procedure.
It depends upon the fact that in order to peek or poke from/to any task,
the debugger must first attach to that task.  And when it does, the
attached task is made a child of the debugger (is chained to its children list).

Therefore we can search just the debugger's children list.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

flush_tlb_all() can be a scaling issue on large SGI Altix systems
since it uses the global call_lock and always executes on all cpus.
When a process enters flush_tlb_range() to purge TLBs for another
process, it is possible to avoid flush_tlb_all() and instead allow
sn2_global_tlb_purge() to purge TLBs only where necessary.

This patch modifies flush_tlb_range() so that this case can be handled
by platform TLB purge functions and updates ia64_global_tlb_purge()
accordingly.  sn2_global_tlb_purge() now calculates the region register
value from the mm argument introduced with this patch.
Signed-off-by: Dean Roe <roe@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

This just makes sure that a thread's expiry times can't get reset after
it clears them in do_exit.

This is what allowed us to re-introduce the stricter BUG_ON() check in
a362f463.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This reverts commit 3de463c7.

Roland has another patch that allows us to leave the BUG_ON() in place
by just making sure that the condition it tests for really is always
true.

That goes in next.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

There's a silly off-by-one error in the code that updates the expiration
of posix CPU timers, causing them to not be properly updated when they
hit exactly on their expiration time (which should be the normal case).

This causes them to then fire immediately again, and only _then_ get
properly updated.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Pointed out by Oleg Nesterov, who has been walking over the code
forwards and backwards.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

I've seen similar failure on alpha.

Obviously, someone forgot to convert sg->handle stuff for
PCI gart case.
Signed-off-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Convert nanoseconds to microseconds correctly.

Spotted by Steve Dickson <SteveD@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fsck_hfs reveals lots of temporary files accumulating in the hidden
directory "\000\000\000HFS+ Private Data".  According to the HFS+
documentation these are files which are unlinked while in use.  However,
there may be a bug in the Linux hfsplus implementation which causes this to
happen even when the files are not in use.  It looks like the "opencnt"
field is never initialized as (I think) it should be in hfsplus_read_inode.
 This means that a file can appear to be still in use when in fact it has
been closed.  This patch seems to fix it for me.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Although this message is having the intended effect of causing wireless
driver maintainers to upgrade their code, I never should have merged this
patch in its present form.  Leading to tons of bug reports and unhappy
users.

Some wireless apps poll for statistics regularly, which leads to a printk()
every single time they ask for stats.  That's a little bit _too_ much of a
reminder that the driver is using an old API.

Change this to printing out the message once, per kernel boot.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

With CONFIG_SMP=n:

*** Warning: "cpu_online_map" [drivers/firmware/dcdbas.ko] undefined!

due to set_cpus_allowed().
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The mpic interrupt controller driver (used on G5 and early pSeries among
others) has a bug where it doesn't get the right virtual address for the
timer registers.  It causes the driver to poke at the MMIO space of
whatever has been mapped just next to it (ouch !) when initializing and
causes boot failures on some IBM machines.
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>

The NUMA counters in struct per_cpu_pageset (linux/mmzone.h) are never
cleared today.  This works ok for CPU 0 on NUMA machines because
boot_pageset[] is already zero, but for other CPU:s this results in
uninitialized counters.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

There are still a couple of cases where md threads (the resync/recovery
thread) is not interruptible since the change to use kthreads.  All places
there it tests "signal_pending", it should also test kthread_should_stop,
as with this patch.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Patch from Ian Campbell

Sparse complains about the definition of generic_fls in asm-arm/bitops.h:
  CHECK   /home/icampbell/devel/kernel/2.6/arch/arm/mach-pxa/viper.c
include2/asm/bitops.h:350:34: error: marked inline, but without a definition

The definition is unnecessary since linux/bitops.h defines generic_fls before including asm/bitops.h and asm/bitops.h should not be included directly. There are still some places where asm/bitops.h is directly included, but I think that code should be fixed. I was a little wary of the patch for this reason but lubbock, mainstone and assabet all build OK and so do my in house boards...

ARM is the only arch with the generic_fls prototype in this way.
Signed-off-by: Ian Campbell <icampbell@arcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

When reserving an PCI quirk, note that in the kernel bootup messages.

Also, parse the strange PIIX4 device resources - they should get their
own PCI resource quirks, but for now just print out what it finds to
verify that the code does the right thing.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

bte_copy() calls calls get_nasid(), which will get flagged if
preemption if enabled.  raw_smp_processor_id() is used instead.
It is OK if we migrate off node.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: Tony Luck <tony.luck@intel.com>