linux-toradex.git/include, branch v2.6.27.47

nfsd: fix vm overcommit crash fix #2

2010-05-26T21:27:09+00:00

commit 1b79cd04fab80be61dcd2732e2423aafde9a4c1c upstream.

The previous patch from Alan Cox ("nfsd: fix vm overcommit crash",
commit 731572d39fcd3498702eda4600db4c43d51e0b26) fixed the problem where
knfsd crashes on exported shmemfs objects and strict overcommit is set.

But the patch forgot supporting the case when CONFIG_SECURITY is
disabled.

This patch copies a part of his fix which is mainly for detecting a bug
earlier.

Acked-by: James Morris 
Signed-off-by: Alan Cox 
Signed-off-by: Junjiro R. Okajima 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nfsd: fix vm overcommit crash

2010-05-26T21:27:09+00:00

commit 731572d39fcd3498702eda4600db4c43d51e0b26 upstream.

Junjiro R.  Okajima reported a problem where knfsd crashes if you are
using it to export shmemfs objects and run strict overcommit.  In this
situation the current->mm based modifier to the overcommit goes through a
NULL pointer.

We could simply check for NULL and skip the modifier but we've caught
other real bugs in the past from mm being NULL here - cases where we did
need a valid mm set up (eg the exec bug about a year ago).

To preserve the checks and get the logic we want shuffle the checking
around and add a new helper to the vm_ security wrappers

Also fix a current->mm reference in nommu that should use the passed mm

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix build]
Reported-by: Junjiro R. Okajima 
Acked-by: James Morris 
Signed-off-by: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

vfs: Remove the range_cont writeback mode.

2010-05-26T21:27:06+00:00

commit 74baaaaec8b4f22e1ae279f5ecca4ff705b28912 upstream.

Ext4 was the only user of range_cont writeback mode and ext4 switched
to a different method. So remove the range_cont mode which is not used
in the kernel.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: "Theodore Ts'o" 
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Jayson R. King 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

percpu counter: clean up percpu_counter_sum_and_set()

2010-05-26T21:27:05+00:00

commit 1f7c14c62ce63805f9574664a6c6de3633d4a354 upstream.

percpu_counter_sum_and_set() and percpu_counter_sum() is the same except
the former updates the global counter after accounting.  Since we are
taking the fbc->lock to calculate the precise value of the counter in
percpu_counter_sum() anyway, it should simply set fbc->count too, as the
percpu_counter_sum_and_set() does.

This patch merges these two interfaces into one.

Signed-off-by: Mingming Cao 
Acked-by: Peter Zijlstra 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Jayson R. King 
Signed-off-by: Theodore Ts'o

KVM: VMX: Check cpl before emulating debug register access

2010-04-01T22:52:24+00:00

commit 0a79b009525b160081d75cef5dbf45817956acf2 upstream.

Debug registers may only be accessed from cpl 0.  Unfortunately, vmx will
code to emulate the instruction even though it was issued from guest
userspace, possibly leading to an unexpected trap later.

Signed-off-by: Avi Kivity 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Greg Kroah-Hartman

KVM: x86 emulator: limit instructions to 15 bytes

2010-04-01T22:52:23+00:00

commit eb3c79e64a70fb8f7473e30fa07e89c1ecc2c9bb upstream

[ : backport to 2.6.27 ]

While we are never normally passed an instruction that exceeds 15 bytes,
smp games can cause us to attempt to interpret one, which will cause
large latencies in non-preempt hosts.

Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

sched: wakeup preempt when small overlap

2010-04-01T22:52:21+00:00

commit 15afe09bf496ae10c989e1a375a6b5da7bd3e16e upstream.

Lin Ming reported a 10% OLTP regression against 2.6.27-rc4.

The difference seems to come from different preemption agressiveness,
which affects the cache footprint of the workload and its effective
cache trashing.

Aggresively preempt a task if its avg overlap is very small, this should
avoid the task going to sleep and find it still running when we schedule
back to it - saving a wakeup.

Reported-by: Lin Ming 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched: fine-tune SD_SIBLING_INIT

2010-04-01T22:52:20+00:00

commit 52c642f33b14bfa1b00ef2b68296effb34a573f3 upstream.

fine-tune the HT sched-domains parameters as well.

On a HT capable box, this increases lat_ctx performance from 23.87
usecs to 1.49 usecs:

 # before

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.89
    2 23.87

 # after

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.84
     2 1.49

Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched: fine-tune SD_MC_INIT

2010-04-01T22:52:20+00:00

commit 14800984706bf6936bbec5187f736e928be5c218 upstream.

Tune SD_MC_INIT the same way as SD_CPU_INIT:
unset SD_BALANCE_NEWIDLE, and set SD_WAKE_BALANCE.

This improves vmark by 5%:

vmark         132102 125968 125497 messages/sec    avg 127855.66    .984
vmark         139404 131719 131272 messages/sec    avg 134131.66   1.033

Signed-off-by: Mike Galbraith 
Acked-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86: fix csum_ipv6_magic asm memory clobber

2010-04-01T22:52:19+00:00

commit 392d814daf460a9564d29b2cebc51e1ea34e0504 upstream.

Just like ip_fast_csum, the assembly snippet in csum_ipv6_magic needs a
memory clobber, as it is only passed the address of the buffer, not a
memory reference to the buffer itself.

This caused failures in Hurd's pfinetv4 when we tried to compile it with
gcc-4.3 (bogus checksums).

Signed-off-by: Samuel Thibault 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Acked-by: "David S. Miller" 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman