linux-stable.git/include/linux, branch linux-2.6.36.y

ieee80211: correct IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK macro

2011-02-17T22:47:27+00:00

commit 8d661f1e462d50bd83de87ee628aaf820ce3c66c upstream.

It is defined in include/linux/ieee80211.h. As per IEEE spec.
bit6 to bit15 in block ack parameter represents buffer size.
So the bitmask should be 0xFFC0.

Signed-off-by: Amitkumar Karwar 
Signed-off-by: Bing Zhao 
Reviewed-by: Johannes Berg 
Signed-off-by: John W. Linville 
Signed-off-by: Greg Kroah-Hartman

klist: Fix object alignment on 64-bit.

2011-02-17T22:47:18+00:00

commit 795abaf1e4e188c4171e3cd3dbb11a9fcacaf505 upstream.

Commit c0e69a5bbc6f ("klist.c: bit 0 in pointer can't be used as flag")
intended to make sure that all klist objects were at least pointer size
aligned, but used the constant "4" which only works on 32-bit.

Use "sizeof(void *)" which is correct in all cases.

Signed-off-by: David S. Miller 
Acked-by: Jesper Nilsson 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: page allocator: adjust the per-cpu counter threshold when memory is low

2011-02-17T22:47:18+00:00

commit 88f5acf88ae6a9778f6d25d0d5d7ec2d57764a97 upstream.

Commit aa45484 ("calculate a better estimate of NR_FREE_PAGES when memory
is low") noted that watermarks were based on the vmstat NR_FREE_PAGES.  To
avoid synchronization overhead, these counters are maintained on a per-cpu
basis and drained both periodically and when a threshold is above a
threshold.  On large CPU systems, the difference between the estimate and
real value of NR_FREE_PAGES can be very high.  The system can get into a
case where pages are allocated far below the min watermark potentially
causing livelock issues.  The commit solved the problem by taking a better
reading of NR_FREE_PAGES when memory was low.

Unfortately, as reported by Shaohua Li this accurate reading can consume a
large amount of CPU time on systems with many sockets due to cache line
bouncing.  This patch takes a different approach.  For large machines
where counter drift might be unsafe and while kswapd is awake, the per-cpu
thresholds for the target pgdat are reduced to limit the level of drift to
what should be a safe level.  This incurs a performance penalty in heavy
memory pressure by a factor that depends on the workload and the machine
but the machine should function correctly without accidentally exhausting
all memory on a node.  There is an additional cost when kswapd wakes and
sleeps but the event is not expected to be frequent - in Shaohua's test
case, there was one recorded sleep and wake event at least.

To ensure that kswapd wakes up, a safe version of zone_watermark_ok() is
introduced that takes a more accurate reading of NR_FREE_PAGES when called
from wakeup_kswapd, when deciding whether it is really safe to go back to
sleep in sleeping_prematurely() and when deciding if a zone is really
balanced or not in balance_pgdat().  We are still using an expensive
function but limiting how often it is called.

When the test case is reproduced, the time spent in the watermark
functions is reduced.  The following report is on the percentage of time
spent cumulatively spent in the functions zone_nr_free_pages(),
zone_watermark_ok(), __zone_watermark_ok(), zone_watermark_ok_safe(),
zone_page_state_snapshot(), zone_page_state().

vanilla                      11.6615%
disable-threshold            0.2584%

David said:

: We had to pull aa454840 "mm: page allocator: calculate a better estimate
: of NR_FREE_PAGES when memory is low and kswapd is awake" from 2.6.36
: internally because tests showed that it would cause the machine to stall
: as the result of heavy kswapd activity.  I merged it back with this fix as
: it is pending in the -mm tree and it solves the issue we were seeing, so I
: definitely think this should be pushed to -stable (and I would seriously
: consider it for 2.6.37 inclusion even at this late date).

Signed-off-by: Mel Gorman 
Reported-by: Shaohua Li 
Reviewed-by: Christoph Lameter 
Tested-by: Nicolas Bareil 
Cc: David Rientjes 
Cc: Kyle McMartin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

USB: serial: handle Data Carrier Detect changes

2011-02-17T22:46:39+00:00

commit d14fc1a74e846d7851f24fc9519fe87dc12a1231 upstream.

Alan's commit 335f8514f200e63d689113d29cb7253a5c282967 introduced
.carrier_raised function in several drivers.  That also means
tty_port_block_til_ready can now suspend the process trying to open the serial
port when Carrier Detect is low and put it into tty_port.open_wait queue.  We
need to wake up the process when Carrier Detect goes high and trigger TTY
hangup when CD goes low.

Some of the devices do not report modem status line changes, or at least we
don't understand the status message, so for those we remove .carrier_raised
again.

Signed-off-by: Libor Pechacek 
Signed-off-by: Greg Kroah-Hartman

block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead

2011-01-07T21:58:51+00:00

commit e692cb668fdd5a712c6ed2a2d6f2a36ee83997b4 upstream.

When stacking devices, a request_queue is not always available. This
forced us to have a no_cluster flag in the queue_limits that could be
used as a carrier until the request_queue had been set up for a
metadevice.

There were several problems with that approach. First of all it was up
to the stacking device to remember to set queue flag after stacking had
completed. Also, the queue flag and the queue limits had to be kept in
sync at all times. We got that wrong, which could lead to us issuing
commands that went beyond the max scatterlist limit set by the driver.

The proper fix is to avoid having two flags for tracking the same thing.
We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the
block layer merging functions. The queue_limit 'no_cluster' is turned
into 'cluster' to avoid double negatives and to ease stacking.
Clustering defaults to being enabled as before. The queue flag logic is
removed from the stacking function, and explicitly setting the cluster
flag is no longer necessary in DM and MD.

Reported-by: Ed Lin 
Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

PM / Runtime: Fix pm_runtime_suspended()

2011-01-07T21:58:32+00:00

commit f08f5a0add20834d3f3d876dfe08005a5df656db upstream.

There are some situations (e.g. in __pm_generic_call()), where
pm_runtime_suspended() is used to decide whether or not to execute
a device's (system) ->suspend() callback.  The callback is not
executed if pm_runtime_suspended() returns true, but it does so
for devices that don't even support runtime PM, because the
power.disable_depth device field is ignored by it.  This leads to
problems (i.e. devices are not suspened when they should), so rework
pm_runtime_suspended() so that it returns false if the device's
power.disable_depth field is different from zero.

Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

sched: Cure more NO_HZ load average woes

2011-01-07T21:58:31+00:00

commit 0f004f5a696a9434b7214d0d3cbd0525ee77d428 upstream.

There's a long-running regression that proved difficult to fix and
which is hitting certain people and is rather annoying in its effects.

Damien reported that after 74f5187ac8 (sched: Cure load average vs
NO_HZ woes) his load average is unnaturally high, he also noted that
even with that patch reverted the load avgerage numbers are not
correct.

The problem is that the previous patch only solved half the NO_HZ
problem, it addressed the part of going into NO_HZ mode, not of
comming out of NO_HZ mode. This patch implements that missing half.

When comming out of NO_HZ mode there are two important things to take
care of:

 - Folding the pending idle delta into the global active count.
 - Correctly aging the averages for the idle-duration.

So with this patch the NO_HZ interaction should be complete and
behaviour between CONFIG_NO_HZ=[yn] should be equivalent.

Furthermore, this patch slightly changes the load average computation
by adding a rounding term to the fixed point multiplication.

Reported-by: Damien Wyart 
Reported-by: Tim McGrath 
Tested-by: Damien Wyart 
Tested-by: Orion Poplawski 
Tested-by: Kyle McMartin 
Signed-off-by: Peter Zijlstra 
Cc: Chase Douglas 
LKML-Reference: <1291129145.32004.874.camel@laptop>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

bootmem: Add alloc_bootmem_align()

2011-01-07T21:58:19+00:00

commit 53dde5f385bc56e312f78b7cb25ffaf8efd4735d upstream.

Add an alloc_bootmem_align() interface to allocate bootmem with
specified alignment.  This is necessary to be able to allocate the
xsave area in a subsequent patch.

Signed-off-by: Suresh Siddha 
LKML-Reference: <20101116212441.977574826@sbsiddha-MOBL3.sc.intel.com>
Acked-by: H. Peter Anvin 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

ASoC: Fix off by one error in WM8994 EQ register bank size

2011-01-07T21:58:18+00:00

commit 3fcc0afbb9c93f3599ba03273e59915670b6c2c2 upstream.

Signed-off-by: Uk Kim 
Acked-by: Liam Girdwood 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

Un-inline get_pipe_info() helper function

2010-12-09T21:33:36+00:00

commit 72083646528d4887b920deb71b37e09bc7d227bb upstream.

This avoids some include-file hell, and the function isn't really
important enough to be inlined anyway.

Reported-by: Ingo Molnar 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman