Commit Graph

87520 Commits

Author SHA1 Message Date
David Brownell
9fedc9f1b1 rtc-at91sam9 fixes
Updates to the at91sam9 rtt-as-rtc driver:

 - Bugfix:  IRQ enable bits need shifting before masking with status
 - Platform code to initialize wakeup bits didn't get merged; cope

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Justin Waters <justin.waters@timesys.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Andrew Morton
3150e63df4 revert "clocksource: make clocksource watchdog cycle through online CPUs"
Revert commit 1ada5cba6a ("clocksource:
make clocksource watchdog cycle through online CPUs") due to the
regression reported by Gabriel C at

	http://lkml.org/lkml/2008/2/24/281

(short vesion: it makes TSC be marked as always unstable on his
machine).

Cc: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Robert Hancock <hancockr@shaw.ca>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Alex Dubov
cf821e8f53 memstick: optimize setup of JMicron host parameters
Set correct clock management values to improve over-all performance.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Alex Dubov
962ee1b10b memstick: add support for 8-bit parallel mode
Newer MemoryStick (HG) cards and hosts support 8-bit parallel mode of
operation in addition to original 4-bit and 1-bit modes.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Alex Dubov
ead7077360 memstick: automatically retrieve "INT" value from command response
MemoryStick storage cards, when in parallel mode, send several meaningful bits
of their "INT" register as part of command response.  This data is stored by
host and can be used to spare invocation of "GET_INT" TPC on each data page
transferred between host and card.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Andrew Morton
9df130392f fs/ufs/balloc.c: fix sparc64 printk warning
fs/ufs/balloc.c: In function `ufs_change_blocknr':
fs/ufs/balloc.c:317: warning: long long unsigned int format, long unsigned int arg (arg 2)
fs/ufs/balloc.c:317: warning: long long unsigned int format, long unsigned int arg (arg 3)

sector_t is u64 and we don't know what type the architecture uses to implement
u64.

Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Andrew Morton
9ea85ebae1 drivers/md/raid5.c: fix printk warnings
gcc-3.4.5 on sparc64:

drivers/md/raid5.c: In function `raid5_end_read_request':
drivers/md/raid5.c:1147: warning: long long unsigned int format, long unsigned int arg (arg 4)
drivers/md/raid5.c:1164: warning: long long unsigned int format, long unsigned int arg (arg 3)
drivers/md/raid5.c:1170: warning: long long unsigned int format, long unsigned int arg (arg 3)

sector_t is u64, and we don't know what type the architecture uses to
implement u64 (on some it is unsigned long).

Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Andrew Morton
8195096bf2 memstick: drivers/memstick/host/jmb38x_ms.c: suppress uninitialized var warning
drivers/memstick/host/jmb38x_ms.c: In function 'jmb38x_ms_transfer_data':
drivers/memstick/host/jmb38x_ms.c:294: warning: 'p_off' may be used uninitialized in this function

Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Andrew Morton
d3597ea2f2 memstick: drivers/memstick/host/jmb38x_ms.c needs dma-mapping.h
sparc32:

drivers/memstick/host/jmb38x_ms.c: In function 'jmb38x_ms_probe':
drivers/memstick/host/jmb38x_ms.c:818: error: 'DMA_32BIT_MASK' undeclared (first use in this function)
drivers/memstick/host/jmb38x_ms.c:818: error: (Each undeclared identifier is reported only once
drivers/memstick/host/jmb38x_ms.c:818: error: for each function it appears in.)

Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Randy Dunlap
f7850d932f mm/readahead: fix kernel-doc notation
Fix kernel-doc notation in mm/readahead.c.

Change ":" to ";" so that it doesn't get treated as a doc section heading.
Move the comment block ending "*/" to a line by itself so that the text on
that last line is not lost (dropped).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:37 -07:00
Dave Young
08ca0db8aa zisofs: fix readpage() outside i_size
A read request outside i_size will be handled in do_generic_file_read().  So
we just return 0 to avoid getting -EIO as normal reading, let
do_generic_file_read do the rest.

At the same time we need unlock the page to avoid system stuck.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=10227

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Jan Kara <jack@suse.cz>
Report-by: Christian Perle <chris@linuxinfotag.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Randy Dunlap
a6b91919e0 fs: fix kernel-doc notation warnings
Fix kernel-doc notation warnings in fs/.

Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line:
 *	mark_files_ro
Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
 *	lease_get_mtime
Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
 *	lease_get_mtime
Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line:
 * lookup_one_len:  filesystem helper to lookup single pathname component
Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line:
 * bh_uptodate_or_lock: Test whether the buffer is uptodate
Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line:
 * bh_submit_read: Submit a locked buffer for reading
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line:
 * writeback_acquire: attempt to get exclusive writeback access to a device
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line:
 * writeback_in_progress: determine whether there is writeback in progress
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line:
 * writeback_release: relinquish exclusive writeback access against a device.
Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections
Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections
Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line:
 * void journal_invalidatepage()

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Michael Halcrow
5366dc9fd1 eCryptfs: Swap dput() and mntput()
ecryptfs_d_release() is doing a mntput before doing the dput.  This patch
moves the dput before the mntput.

Thanks to Rajouri Jammu for reporting this.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Rajouri Jammu <rajouri.jammu@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Paul E. McKenney
ae66be9b71 rcu: fix misplaced mb() in rcu_enter/exit_nohz()
In the process of writing up the mechanical proof of correctness for the
dynticks/preemptable-RCU interface, I noticed misplaced memory barriers in
rcu_enter_nohz() and rcu_exit_nohz().

This patch puts them in the right place and adds a comment.  The key thing to
keep in mind is that rcu_enter_nohz() is -exiting- the mode that can legally
execute RCU read-side critical sections.

The memory barrier must be between any potential RCU read-side critical
sections and the increment of the per-CPU dynticks_progress_counter, and thus
must come -before- this increment.  And vice versa for rcu_exit_nohz().

The locking in the scheduler is probably saving us for the moment.

Also, switch to smp_mb() - we don't need a barrier for uniprocessor kernels.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Stefan Bauer
b691da35ba i810fb: fix console switch regression
Since 4c7ffe0b9f ("fbdev: prevent drivers that
have hardware cursors from calling software cursor code") every call of
i810fb_cursor fails with -ENXIO because of a incorrect "!".

This hasn't struck until eaa0ff15c3 ("fix !
versus & precedence in various places") surrounded the expression with braces,
so that the intended behavior was inverted.  That caused 'pixel waste' - the
same line of multi-colored pixels repeated over the whole screen - during
console switch.

This switches back to the original pre-4c7ffe0 behavior.

Signed-off-by: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
Tested-by: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Antonino Daplas <adaplas@pol.net>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Duane Griffin
d00256766a jbd2: correctly unescape journal data blocks
Fix a long-standing typo (predating git) that will cause data corruption if a
journal data block needs unescaping.  At the moment the wrong buffer head's
data is being unescaped.

To test this case mount a filesystem with data=journal, start creating and
deleting a bunch of files containing only JBD2_MAGIC_NUMBER (0xc03b3998), then
pull the plug on the device.  Without this patch the files will contain zeros
instead of the correct data after recovery.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Duane Griffin
439aeec639 jbd: correctly unescape journal data blocks
Fix a long-standing typo (predating git) that will cause data corruption if a
journal data block needs unescaping.  At the moment the wrong buffer head's
data is being unescaped.

To test this case mount a filesystem with data=journal, start creating and
deleting a bunch of files containing only JFS_MAGIC_NUMBER (0xc03b3998), then
pull the plug on the device.  Without this patch the files will contain zeros
instead of the correct data after recovery.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Alessandro Zummo
44e0451db0 rtc: fix kconfig help
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Ahmed S. Darwish
1d252fb870 smack: do not dereference NULL ipc object
In the SYSV ipc msgctl(),semctl(),shmctl() family, if the user passed *_INFO
as the desired operation, no specific object is meant to be controlled and
only system-wide information is returned.  This leads to a NULL IPC object in
the LSM hooks if the _INFO flag is given.

Avoid dereferencing this NULL pointer in Smack ipc *ctl() methods.

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
David Howells
4ebf89845b ROMFS: Fix up an error in iget removal
Fix up an error in iget removal in which romfs_lookup() making a successful
call to romfs_iget() continues through the negative/error handling (previously
the successful case jumped around the negative/error handling case):

 (1) inode is initialised to NULL at the top of the function, eliminating the
     need for specific negative-inode handling.  This means the positive
     success handling now flows straight through.

 (2) Rename the labels to be clearer about what they mean.

Also make romfs_lookup()'s result variable of type long so as to avoid
32-bit/64-bit conversions with PTR_ERR() and friends.

Based upon a report and patch from Adam Richter.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: "Adam J. Richter" <adam@yggdrasil.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Josef Bacik
c587f0c0a6 ext3: fix wrong gfp type under transaction
There are several places where we make allocations with GFP_KERNEL while under
a transaction, which could lead to an assertion panic or lockup if under
memory pressure.  This patch switches these problem areas to use GFP_NOFS to
keep these problems from happening.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Darrick J. Wong
ffda6857c8 ibmpex: report temperatures in mC, not C
ibmpex's temperature sensors report incorrect units.  Apply a conversion
factor so that tempertures report correctly.  Until now, no systems seemed to
report temperatures this way, but evidently QS2x blades do.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:36 -07:00
Darrick J. Wong
3d960a99ab ibmpex: update Kconfig to list more supported models
Enhanced the list of supported machines.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Darrick J. Wong
df9cb0339f ibmpex: correct power use multipliers for QS2x blade
The QS2x blades ships with v2.54 of the firmware, which use the same
multiplier for all power meters.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Jan Kara
87cb055bc1 quota: add possibly missing iput() when quotaon and quotaoff races
We should always put inode we have reference to, even if quota was reenabled
in the mean time.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Pavel Emelyanov
52ea27eb4c memcgroup: fix check for thread being a group leader in memcgroup
The check t->pid == t->pid is not the blessed way to check whether a task is a
group leader.

This is not about the code beautifulness only, but about pid namespaces fixes
- both the tgid and the pid fields on the task_struct are (slowly :( )
becoming deprecated.

Besides, the thread_group_leader() macro makes only one dereference :)

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Randy Dunlap
0cf01f6685 jbd: fix jbd kernel-doc notation
Fix kernel-doc notation in jbd.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
NeilBrown
0e82989d95 md: remove the 'super' sysfs attribute from devices in an 'md' array
Exposing the binary blob which is the md 'super-block' via sysfs doesn't
really fit with the whole sysfs model, and ever since commit
8118a859dc ("sysfs: fix off-by-one error
in fill_read_buffer()") it doesn't actually work at all (as the size of
the blob is often one page).

(akpm: as in, fs/sysfs/file.c:fill_read_buffer() goes BUG)

So just remove it altogether.  It isn't really useful.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Randy Dunlap
43d8eac44f mm: rmap kernel-doc fixes
Correct kernel-doc function names and parameters in rmap.c.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Randy Dunlap
77f6078aa8 mm: highmem kernel-doc additions
Add kernel-doc comments to highmem.c.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Randy Dunlap
1b578df022 mm/oom_kill: fix kernel-doc
Fix kernel-doc notation in oom_kill.c.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Randy Dunlap
4671181020 mm/shmem and tiny-shmem: fix some kernel-doc
Convert tiny-shmem.c function comments to kernel-doc.  Add parameters and
convert/fix other kernel-doc in shmem.c.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Randy Dunlap
7682486b3e mm: fix various kernel-doc comments
Fix various kernel-doc notation in mm/:

filemap.c: add function short description; convert 2 to kernel-doc
fremap.c: change parameter 'prot' to @prot
pagewalk.c: change "-" in function parameters to ":"
slab.c: fix short description of kmem_ptr_validate()
swap.c: fix description & parameters of put_pages_list()
swap_state.c: fix function parameters
vmalloc.c: change "@returns" to "Returns:" since that is not a parameter

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Quentin Barnes
6cb2a21049 aio: bad AIO race in aio_complete() leads to process hang
My group ran into a AIO process hang on a 2.6.24 kernel with the process
sleeping indefinitely in io_getevents(2) waiting for the last wakeup to come
and it never would.

We ran the tests on x86_64 SMP.  The hang only occurred on a Xeon box
("Clovertown") but not a Core2Duo ("Conroe").  On the Xeon, the L2 cache isn't
shared between all eight processors, but is L2 is shared between between all
two processors on the Core2Duo we use.

My analysis of the hang is if you go down to the second while-loop
in read_events(), what happens on processor #1:
	1) add_wait_queue_exclusive() adds thread to ctx->wait
	2) aio_read_evt() to check tail
	3) if aio_read_evt() returned 0, call [io_]schedule() and sleep

In aio_complete() with processor #2:
	A) info->tail = tail;
	B) waitqueue_active(&ctx->wait)
	C) if waitqueue_active() returned non-0, call wake_up()

The way the code is written, step 1 must be seen by all other processors
before processor 1 checks for pending events in step 2 (that were recorded by
step A) and step A by processor 2 must be seen by all other processors
(checked in step 2) before step B is done.

The race I believed I was seeing is that steps 1 and 2 were
effectively swapped due to the __list_add() being delayed by the L2
cache not shared by some of the other processors.  Imagine:
proc 2: just before step A
proc 1, step 1: adds to ctx->wait, but is not visible by other processors yet
proc 1, step 2: checks tail and sees no pending events
proc 2, step A: updates tail
proc 1, step 3: calls [io_]schedule() and sleeps
proc 2, step B: checks ctx->wait, but sees no one waiting, skips wakeup
                so proc 1 sleeps indefinitely

My patch adds a memory barrier between steps A and B.  It ensures that the
update in step 1 gets seen on processor 2 before continuing.  If processor 1
was just before step 1, the memory barrier makes sure that step A (update
tail) gets seen by the time processor 1 makes it to step 2 (check tail).

Before the patch our AIO process would hang virtually 100% of the time.  After
the patch, we have yet to see the process ever hang.

Signed-off-by: Quentin Barnes <qbarnes+linux@yahoo-inc.com>
Reviewed-by: Zach Brown <zach.brown@oracle.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: <stable@kernel.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ We should probably disallow that "if (waitqueue_active()) wake_up()"
  coding pattern, because it's so often buggy wrt memory ordering ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19 18:53:35 -07:00
Linus Torvalds
264e3e889d Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  async_tx: avoid the async xor_zero_sum path when src_cnt > device->max_xor
  fsldma: Fix the DMA halt when using DMA_INTERRUPT async_tx transfer.
2008-03-18 21:34:48 -07:00
Alexey Starikovskiy
d7a0e1f564 Revert "ACPI: EC: Handle IRQ storm on Acer laptops"
This reverts commit 2c81ce4c9c.

It caused several new troubles (eg suspend slowdown bisected down to
this patch by Pavel Machek), so just revert it for now.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-18 21:32:24 -07:00
Linus Torvalds
2caf470363 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel:
  sched: tune multi-core idle balancing
  sched: retune wake granularity
  sched: wakeup-buddy tasks are cache-hot
  sched: improve affine wakeups
  sched, net: socket wakeups are sync
  sched: clean up wakeup balancing, code flow
  sched: clean up wakeup balancing, rename variables
  sched: clean up wakeup balancing, move wake_affine()
2008-03-18 21:27:13 -07:00
Linus Torvalds
6c3c3158a8 IDE: Make taskfile interface more robust wrt unexpected end-of-command
Now that we handle all the special commands using REQ_TYPE_ATA_TASKFILE
rather than using the old REQ_TYPE_ATA_CMD model, we need to also
emulate the lack of full taskfile data that comes with the old command
model (ie when commands are generated with the HDIO_DRIVE_CMD ioctl
rather than using the HDIO_DRIVE_TASK[FILE] ioctls).

In particular, this means that we should handle command completion the
more relaxed way that the old drive_cmd_intr() code did.  It allows
commands to finish early even if they don't use up all the data that we
thought we had for them.

This fixes a regression seen by Anders Eriksson where some SMART
commands sent by smartd would cause a boot-time system hang on his
machine because the IDE command handling code didn't realize that the
command had completed.

Tested-by: Anders Eriksson <aeriksson@fastmail.fm>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-18 21:26:24 -07:00
Linus Torvalds
d5eee40572 Merge branch 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm
* 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
  slub page alloc fallback: Enable interrupts for GFP_WAIT.
2008-03-18 21:13:19 -07:00
Ingo Molnar
33b0c4217d sched: tune multi-core idle balancing
WAKE_IDLE is too agressive on multi-core CPUs with the new
wake-affine code, keep it on for SMT/HT balancing alone
(where there's no cache affinity at all between logical CPUs).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
74e3cd7f48 sched: retune wake granularity
reduce wake-up granularity for better interactivity.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
f540a6080a sched: wakeup-buddy tasks are cache-hot
Wakeup-buddy tasks are cache-hot - this makes it a bit harder
for the load-balancer to tear them apart. (but it's still possible,
if the load is sufficiently assymetric)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
4ae7d5cefd sched: improve affine wakeups
improve affine wakeups. Maintain the 'overlap' metric based on CFS's
sum_exec_runtime - which means the amount of time a task executes
after it wakes up some other task.

Use the 'overlap' for the wakeup decisions: if the 'overlap' is short,
it means there's strong workload coupling between this task and the
woken up task. If the 'overlap' is large then the workload is decoupled
and the scheduler will move them to separate CPUs more easily.

( Also slightly move the preempt_check within try_to_wake_up() - this has
  no effect on functionality but allows 'early wakeups' (for still-on-rq
  tasks) to be correctly accounted as well.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
6f3d09291b sched, net: socket wakeups are sync
'sync' wakeups are a hint towards the scheduler that (certain)
networking related wakeups likely create coupling between tasks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
f48273860e sched: clean up wakeup balancing, code flow
Clean up the code flow. No code changed:

kernel/sched.o:

   text	   data	    bss	    dec	    hex	filename
  42521	   2858	    232	  45611	   b22b	sched.o.before
  42521	   2858	    232	  45611	   b22b	sched.o.after

md5:
   09b31c44e9aff8666f72773dc433e2df  sched.o.before.asm
   09b31c44e9aff8666f72773dc433e2df  sched.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
ac192d3921 sched: clean up wakeup balancing, rename variables
rename 'cpu' to 'prev_cpu'. No code changed:

kernel/sched.o:

   text	   data	    bss	    dec	    hex	filename
  42521	   2858	    232	  45611	   b22b	sched.o.before
  42521	   2858	    232	  45611	   b22b	sched.o.after

md5:
   09b31c44e9aff8666f72773dc433e2df  sched.o.before.asm
   09b31c44e9aff8666f72773dc433e2df  sched.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:52 +01:00
Ingo Molnar
098fb9db2c sched: clean up wakeup balancing, move wake_affine()
split out the affine-wakeup bits.

No code changed:

kernel/sched.o:

   text	   data	    bss	    dec	    hex	filename
  42521	   2858	    232	  45611	   b22b	sched.o.before
  42521	   2858	    232	  45611	   b22b	sched.o.after

md5:
   9d76738f1272aa82f0b7affd2f51df6b  sched.o.before.asm
   09b31c44e9aff8666f72773dc433e2df  sched.o.after.asm

(the md5's changed because stack slots changed and some registers
get scheduled by gcc in a different order - but otherwise the before
and after assembly is instruction for instruction equivalent.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:52 +01:00
Dan Williams
8d8002f642 async_tx: avoid the async xor_zero_sum path when src_cnt > device->max_xor
If the channel cannot perform the operation in one call to
->device_prep_dma_zero_sum, then fallback to the xor+page_is_zero path.
This only affects users with arrays larger than 16 devices on iop13xx or
32 devices on iop3xx.

Cc: <stable@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-03-18 17:01:00 -07:00
Zhang Wei
f79abb627f fsldma: Fix the DMA halt when using DMA_INTERRUPT async_tx transfer.
The DMA_INTERRUPT async_tx is a NULL transfer, thus the BCR(count register)
is 0. When the transfer started with a byte count of zero, the DMA
controller will triger a PE(programming error) event and halt, not a normal
interrupt. I add special codes for PE event and DMA_INTERRUPT
async_tx testing.

Signed-off-by: Zhang Wei <wei.zhang@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-03-18 17:00:59 -07:00
Linus Torvalds
f920bb6f5f Merge branch 'audit.b49' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b49' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] export sessionid alongside the loginuid in procfs
2008-03-18 08:43:59 -07:00