Signed-off-by: Jens Axboe <axboe@suse.de>

- 100msec sleep is a little excessive, lots of requests can complete
  in that timeframe. Use 10msec instead.
- Rename QUEUE_FLAG_BYPASS to QUEUE_FLAG_ELVSWITCH to indicate what
  is going on.
Signed-off-by: Jens Axboe <axboe@suse.de>

 This patch reimplements elevator switch.  This patch assumes generic
dispatch queue patchset is applied.

 * Each request is tagged with REQ_ELVPRIV flag if it has its elevator
   private data set.
 * Requests which doesn't have REQ_ELVPRIV flag set never enter
   iosched.  They are always directly back inserted to dispatch queue.
   Of course, elevator_put_req_fn is called only for requests which
   have its REQ_ELVPRIV set.
 * Request queue maintains the current number of requests which have
   its elevator data set (elevator_set_req_fn called) in
   q->rq->elvpriv.
 * If a request queue has QUEUE_FLAG_BYPASS set, elevator private data
   is not allocated for new requests.

 To switch to another iosched, we set QUEUE_FLAG_BYPASS and wait until
elvpriv goes to zero; then, we attach the new iosched and clears
QUEUE_FLAG_BYPASS.  New implementation is much simpler and main code
paths are less cluttered, IMHO.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

This patch kills max_back_kb handling from elv_dispatch_sort() and
kills max_back_kb field from struct request_queue.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

Updates biodoc to reflect changes in elevator API
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

Remove last_merge handling from all ioscheds.  This patch
removes merging capability of noop iosched.
Signed-off-by: Tejun Heo <htejun@gmail.com>

Currently, both generic elevator code and specific ioscheds
participate in the management and usage of last_merge.  This
and the following patches move last_merge handling into
generic elevator code.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

This patch updates all four ioscheds to use generic dispatch
queue.  There's one behavior change in as-iosched.

* In as-iosched, when force dispatching
  (ELEVATOR_INSERT_BACK), batch_data_dir is reset to REQ_SYNC
  and changed_batch and new_batch are cleared to zero.  This
  prevernts AS from doing incorrect update_write_batch after
  the forced dispatched requests are finished.

* In cfq-iosched, cfqd->rq_in_driver currently counts the
  number of activated (removed) requests to determine
  whether queue-kicking is needed and cfq_max_depth has been
  reached.  With generic dispatch queue, I think counting
  the number of dispatched requests would be more appropriate.

* cfq_max_depth can be lowered to 1 again.

Original from Tejun Heo, modified version applied.
Signed-off-by: Jens Axboe <axboe@suse.de>

Signed-off-by: Jens Axboe <axboe@suse.de>

- Split elv_dispatch_insert() into two functions
- Rename rq_last_sector() to rq_end_sector()
Signed-off-by: Jens Axboe <axboe@suse.de>

Implements generic dispatch queue which can replace all
dispatch queues implemented by each iosched.  This reduces
code duplication, eases enforcing semantics over dispatch
queue, and simplifies specific ioscheds.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

This patch removes try_module_get race in elevator_find.
try_module_get should always be called with the spinlock protecting
what the module init/cleanup routines register/unregister to held. In
the case of elevators, we should be holding elv_list to avoid it going
away between spin_unlock_irq and try_module_get.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

disk stat when "now" is different from disk->stamp.  Otherwise, we
are again needlessly adding zero to the stats.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

struct gendisk has these two fields: stamp, stamp_idle.  Update to
stamp_idle is always in sync with stamp and they are always the same.
Therefore, it does not add any value in having two fields tracking
same timestamp.  Suggest to remove it.

Also, we should only update gendisk stats with non-zero value.
Advantage is that we don't have to needlessly calculate memory address,
and then add zero to the content.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

"Better late than never"

Don't try to access not-present CPUs.  Conservative governor will always
oops on SMP without this fix.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=4781Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Commit id 6142891a

Andi Kleen reports that it seems to break things for some people,
and since it's purely a small optimization, revert it for now.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This bug is responsible for causing the infamous "Treason uncloaked"
messages that's been popping up everywhere since the printk was added.
It has usually been blamed on foreign operating systems.  However,
some of those reports implicate Linux as both systems are running
Linux or the TCP connection is going across the loopback interface.

In fact, there really is a bug in the Linux TCP header prediction code
that's been there since at least 2.1.8.  This bug was tracked down with
help from Dale Blount.

The effect of this bug ranges from harmless "Treason uncloaked"
messages to hung/aborted TCP connections.  The details of the bug
and fix is as follows.

When snd_wnd is updated, we only update pred_flags if
tcp_fast_path_check succeeds.  When it fails (for example,
when our rcvbuf is used up), we will leave pred_flags with
an out-of-date snd_wnd value.

When the out-of-date pred_flags happens to match the next incoming
packet we will again hit the fast path and use the current snd_wnd
which will be wrong.

In the case of the treason messages, it just happens that the snd_wnd
cached in pred_flags is zero while tp->snd_wnd is non-zero.  Therefore
when a zero-window packet comes in we incorrectly conclude that the
window is non-zero.

In fact if the peer continues to send us zero-window pure ACKs we
will continue making the same mistake.  It's only when the peer
transmits a zero-window packet with data attached that we get a
chance to snap out of it.  This is what triggers the treason
message at the next retransmit timeout.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.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>

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

Signed-off-by: Yan Zheng <yanzheng@21cn.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

If qla2x00_probe_one()'s call to qla2x00_iospace_config() fails, we call
qla2x00_free_device() to clean up.  But because ha->dpc_pid hasn't been set
yet, qla2x00_free_device() tries to stop a kernel thread which hasn't started
yet.  It does wait_for_completion() against an uninitialised completion struct
and the kernel hangs up.

Fix it by initialising ha->dpc_pid a bit earlier.

Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

My alpha build is exploding because asm/atomic.h now needs smb_mb(), which is
over in the (not included) system.h.

I fear what will happen if I include system.h into atomic.h, so let's put the
barriers into their own header file.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>