Set the class so it doesn't clash with the normal memory class.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
===================================================================

Exception stacks are allocated each time a CPU is set online.
But the allocated space is never freed. Thus with one CPU hotplug
offline/online cycle there is a memory leak of 24K (6 pages) for
a CPU.

Fix is to allocate exception stacks only once -- when the CPU is
set online for the first time.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

pda->irqstackptr is allocated whenever a CPU is set online.
But it is never freed. This results in a memory leak of 16K
for each CPU offline/online cycle.

Fix is to allocate pda->irqstackptr only once.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Using native_pte_val triggers the BUG_ON() in the paravirt_ops
version of pte_flags().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Krzysztof Helt found MTRR is not detected on k6-2

root cause:
	we moved mtrr_bp_init() early for mtrr trimming,
and in early_detect we only read the CPU capability from cpuid,
so some cpu doesn't have that bit in cpuid.

So we need to add early_init_xxxx to preset those bit before mtrr_bp_init
for those earlier cpus.

this patch is for v2.6.27
Reported-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move early cpu initialization after cpu early get cap so the
early cpu initialization can fix up cpu caps.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use X86_FEATURE_NOPL to determine if it is safe to use P6 NOPs in
alternatives.  Also, replace table and loop with simple if statement.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The long noops ("NOPL") are supposed to be detected by family >= 6.
Unfortunately, several non-Intel x86 implementations, both hardware
and software, don't obey this dictum.  Instead, probe for NOPL
directly by executing a NOPL instruction and see if we get #UD.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The CPU feature detection code in the boot code is somewhat minimal,
and doesn't include all possible CPUID words.  In particular, it
doesn't contain the code for CPU feature words 2 (Transmeta),
3 (Linux-specific), 5 (VIA), or 7 (scattered).  Zero them out, so we
can still set those bits as known at compile time; in particular, this
allows creating a Linux-specific NOPL flag and have it required (and
therefore resolvable at compile time) in 64-bit mode.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Manually adding "io_delay=0xed" fixes system lockups in ioapic
mode on this machine.

System Information
	Manufacturer: Hewlett-Packard
	Product Name: Presario F700 (KA695EA#ABF)

Base Board Information
	Manufacturer: Quanta
	Product Name: 30D3

Reference:
https://bugzilla.redhat.com/show_bug.cgi?id=459546Signed-off-by: NChuck Ebbert <cebbert@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The TSC calibration function is still very complicated, but this makes
it at least a little bit less so by moving the PIT part out into a
helper function of its own.
Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-of-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  ipsec: Fix deadlock in xfrm_state management.
  ipv: Re-enable IP when MTU > 68
  net/xfrm: Use an IS_ERR test rather than a NULL test
  ath9: Fix ath_rx_flush_tid() for IRQs disabled kernel warning message.
  ath9k: Incorrect key used when group and pairwise ciphers are different.
  rt2x00: Compiler warning unmasked by fix of BUILD_BUG_ON
  mac80211: Fix debugfs union misuse and pointer corruption
  wireless/libertas/if_cs.c: fix memory leaks
  orinoco: Multicast to the specified addresses
  iwlwifi: fix 64bit platform firmware loading
  iwlwifi: fix apm_stop (wrong bit polarity for FLAG_INIT_DONE)
  iwlwifi: workaround interrupt handling no some platforms
  iwlwifi: do not use GFP_DMA in iwl_tx_queue_init
  net/wireless/Kconfig: clarify the description for CONFIG_WIRELESS_EXT_SYSFS
  net: Unbreak userspace usage of linux/mroute.h
  pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()
  ipv6: When we droped a packet, we should return NET_RX_DROP instead of 0

Larry Finger reported at http://lkml.org/lkml/2008/9/1/90:
An ancient laptop of mine started throwing errors from b43legacy when
I started using 2.6.27 on it. This has been bisected to commit bfc0f594
"x86: merge tsc calibration".

The unification of the TSC code adopted mostly the 64bit code, which
prefers PMTIMER/HPET over the PIT calibration.

Larrys system has an AMD K6 CPU. Such systems are known to have
PMTIMER incarnations which run at double speed. This results in a
miscalibration of the TSC by factor 0.5. So the resulting calibrated
CPU/TSC speed is half of the real CPU speed, which means that the TSC
based delay loop will run half the time it should run. That might
explain why the b43legacy driver went berserk.

On the other hand we know about systems, where the PIT based
calibration results in random crap due to heavy SMI/SMM
disturbance. On those systems the PMTIMER/HPET based calibration logic
with SMI detection shows better results.

According to Alok also virtualized systems suffer from the PIT
calibration method.

The solution is to use a more wreckage aware aproach than the current
either/or decision.

1) reimplement the retry loop which was dropped from the 32bit code
during the merge. It repeats the calibration and selects the lowest
frequency value as this is probably the closest estimate to the real
frequency

2) Monitor the delta of the TSC values in the delay loop which waits
for the PIT counter to reach zero. If the maximum value is
significantly different from the minimum, then we have a pretty safe
indicator that the loop was disturbed by an SMI.

3) keep the pmtimer/hpet reference as a backup solution for systems
where the SMI disturbance is a permanent point of failure for PIT
based calibration

4) do the loop iteration for both methods, record the lowest value and
decide after all iterations finished.

5) Set a clear preference to PIT based calibration when the result
makes sense.

The implementation does the reference calibration based on
HPET/PMTIMER around the delay, which is necessary for the PIT anyway,
but keeps separate TSC values to ensure the "independency" of the
resulting calibration values.

Tested on various 32bit/64bit machines including Geode 266Mhz, AMD K6
(affected machine with a double speed pmtimer which I grabbed out of
the dump), Pentium class machines and AMD/Intel 64 bit boxen.
Bisected-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Ever since commit 4c563f76
("[XFRM]: Speed up xfrm_policy and xfrm_state walking") it is
illegal to call __xfrm_state_destroy (and thus xfrm_state_put())
with xfrm_state_lock held.  If we do, we'll deadlock since we
have the lock already and __xfrm_state_destroy() tries to take
it again.

Fix this by pushing the xfrm_state_put() calls after the lock
is dropped.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix a bug reported by and diagnosed by Aaron Straus.

This is a regression intruduced into 2.6.26 by

    commit adc782da
    Author: Matt Mackall <mpm@selenic.com>
    Date:   Tue Apr 29 01:03:07 2008 -0700

        random: simplify and rename credit_entropy_store

credit_entropy_bits() does:

	spin_lock_irqsave(&r->lock, flags);
	...
	if (r->entropy_count > r->poolinfo->POOLBITS)
		r->entropy_count = r->poolinfo->POOLBITS;

so there is a time window in which this BUG_ON():

static size_t account(struct entropy_store *r, size_t nbytes, int min,
		      int reserved)
{
	unsigned long flags;

	BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);

	/* Hold lock while accounting */
	spin_lock_irqsave(&r->lock, flags);

can trigger.

We could fix this by moving the assertion inside the lock, but it seems
safer and saner to revert to the old behaviour wherein
entropy_store.entropy_count at no time exceeds
entropy_store.poolinfo->POOLBITS.
Reported-by: NAaron Straus <aaron@merfinllc.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make PM_QOS and CPU_IDLE play nicer when run with the RT-Preempt kernel.

The purpose of the patch is to remove the spin_lock around the read in the
function pm_qos_requirement - since spinlocks can sleep in -rt and this
function is called from idle.

CPU_IDLE polls the target_value's of some of the pm_qos parameters from
the idle loop causing sleeping locking warnings.  Changing the
target_value to an atomic avoids this issue.

Remove the spinlock in pm_qos_requirement by making target_value an atomic
type.
Signed-off-by: Nmark gross <mgross@linux.intel.com>
Signed-off-by: NJohn Kacur <jkacur@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update rtc-cmos shutdown handling to leave RTC alarms active, resolving
http://bugzilla.kernel.org/show_bug.cgi?id=11411 on several boards.  There
are still some systems where the ACPI event handling doesn't cooperate.
(Possibly related to bugid 11312, reporting the spontaneous disabling of
RTC events.)

Bug 11411 reported that changes to work around some ACPI event issues
broke wake-from-S5 handling, as used for DVR applications.  (They like to
power off, then wake later to record programs.)

[yakui.zhao@intel.com: add shutdown for PNP devices]
[dbrownell@users.sourceforge.net: update comments]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Document files in /sys/firmware/sgi_uv/.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I got this patch through Red Hat's bugzilla from the bug submitter and
patch creator.  I have just fixed it up so it applies without fuzz to
upstream kernels.

Original patch and description from Shyam kumar Iyer:

The issue [ibft module not displaying targets with short names] is because
of an offset calculatation error in the iscsi_ibft.c code.  Due to this
error directory structure for the target in /sys/firmware/ibft does not
get created and so the initiator is unable to connect to the target.

Note that this bug surfaced only with an name that had a short section at
the end.  eg: "iqn.1984-05.com.dell:dell".  It did not surface when the
iqn's had a longer section at the end.  eg:
"iqn.2001-04.com.example:storage.disk2.sys1.xyz"

So, the eot_offset was calculated such that an extra 48 bytes i.e.  the
size of the ibft_header which has already been accounted was subtracted
twice.

This was not evident with longer iqn names because they would overshoot
the total ibft length more than 48 bytes and thus would escape the bug.
Signed-off-by: NShyam Kumar Iyer <shyam_iyer@dell.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Konrad Rzeszutek <konrad@virtualiron.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 945185a6 ("rtc: rtc_time_to_tm: use
unsigned arithmetic") changed the some types in rtc_time_to_tm() to
unsigned:

 void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
 {
-       register int days, month, year;
+       unsigned int days, month, year;

This doesn't work for all cases, because days is checked for < 0 later
on:

if (days < 0) {
	year -= 1;
	days += 365 + LEAP_YEAR(year);
}

I think the correct fix would be to keep days signed and do an appropriate
cast later on.
Signed-off-by: NJan Altenberg <jan.altenberg@linutronix.de>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If there are more then one graphics card handled by the tdfxfb driver the
name of the frame buffer overruns reserved size.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix memory detection on Voodoo3 cards with SDRAM memory.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It turns out that event 0x4 merely indcates that a hotkey has been
pressed, not which one.  A further query is required in order to determine
the actual keypress.  The following patch adds support for that along with
the known keycodes.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

hp-wmi currently changes the RFKill state by altering the struct members
rather than using the dedicated interface, meaning that update events
won't be pushed to userspace.  This patch fixes that, along with fixing
the declared type of the WWAN kill switch.  It also ensures that rfkill
interfaces are only registered for hardware that exists.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <ivdoorn@gmail.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update Documentation/filesystems/proc.txt: it describes the file
auto_msgmni intoduced to enable/disable msgmni automatic recomputing upon
memory add/remove (see thread http://lkml.org/lkml/2008/7/4/27).  Also
added a description for msgmni (this filex is only listed in
Documentation/sysctl/kernel.txt).
Signed-off-by: NNadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Quicklists store pages for each CPU as caches.  (Each CPU can cache
node_free_pages/16 pages)

It is used for page table cache.  exit() will increase the cache size,
while fork() consumes it.

So for example if an apache-style application runs (one parent and many
child model), one CPU process will fork() while another CPU will process
the middleware work and exit().

At that time, the CPU on which the parent runs doesn't have page table
cache at all.  Others (on which children runs) have maximum caches.

	QList_max = (#ofCPUs - 1) x Free / 16
	=> QList_max / (Free + QList_max) = (#ofCPUs - 1) / (16 + #ofCPUs - 1)

So, How much quicklist memory is used in the maximum case?

This is proposional to # of CPUs because the limit of per cpu quicklist
cache doesn't see the number of cpus.

Above calculation mean

	 Number of CPUs per node            2    4    8   16
	 ==============================  ====================
	 QList_max / (Free + QList_max)   5.8%  16%  30%  48%

Wow! Quicklist can spend about 50% memory at worst case.

My demonstration program is here
--------------------------------------------------------------------------------
#define _GNU_SOURCE

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sched.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>

#define BUFFSIZE 512

int max_cpu(void)	/* get max number of logical cpus from /proc/cpuinfo */
{
  FILE *fd;
  char *ret, buffer[BUFFSIZE];
  int cpu = 1;

  fd = fopen("/proc/cpuinfo", "r");
  if (fd == NULL) {
    perror("fopen(/proc/cpuinfo)");
    exit(EXIT_FAILURE);
  }
  while (1) {
    ret = fgets(buffer, BUFFSIZE, fd);
    if (ret == NULL)
      break;
    if (!strncmp(buffer, "processor", 9))
      cpu = atoi(strchr(buffer, ':') + 2);
  }
  fclose(fd);
  return cpu;
}

void cpu_bind(int cpu)	/* bind current process to one cpu */
{
  cpu_set_t mask;
  int ret;

  CPU_ZERO(&mask);
  CPU_SET(cpu, &mask);
  ret = sched_setaffinity(0, sizeof(mask), &mask);
  if (ret == -1) {
    perror("sched_setaffinity()");
    exit(EXIT_FAILURE);
  }
  sched_yield();	/* not necessary */
}

#define MMAP_SIZE (10 * 1024 * 1024)	/* 10 MB */
#define FORK_INTERVAL 1	/* 1 second */

main(int argc, char *argv[])
{
  int cpu_max, nextcpu;
  long pagesize;
  pid_t pid;

  /* set max number of logical cpu */
  if (argc > 1)
    cpu_max = atoi(argv[1]) - 1;
  else
    cpu_max = max_cpu();

  /* get the page size */
  pagesize = sysconf(_SC_PAGESIZE);
  if (pagesize == -1) {
    perror("sysconf(_SC_PAGESIZE)");
    exit(EXIT_FAILURE);
  }

  /* prepare parent process */
  cpu_bind(0);
  nextcpu = cpu_max;

loop:

  /* select destination cpu for child process by round-robin rule */
  if (++nextcpu > cpu_max)
    nextcpu = 1;

  pid = fork();

  if (pid == 0) { /* child action */

    char *p;
    int i;

    /* consume page tables */
    p = mmap(0, MMAP_SIZE, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
    i = MMAP_SIZE / pagesize;
    while (i-- > 0) {
      *p = 1;
      p += pagesize;
    }

    /* move to other cpu */
    cpu_bind(nextcpu);
/*
    printf("a child moved to cpu%d after mmap().\n", nextcpu);
    fflush(stdout);
 */

    /* back page tables to pgtable_quicklist */
    exit(0);

  } else if (pid > 0) { /* parent action */

    sleep(FORK_INTERVAL);
    waitpid(pid, NULL, WNOHANG);

  }

  goto loop;
}
----------------------------------------

When above program which does task migration runs, my 8GB box spends
800MB of memory for quicklist.  This is not memory leak but doesn't seem
good.

% cat /proc/meminfo

MemTotal:        7701568 kB
MemFree:         4724672 kB
(snip)
Quicklists:       844800 kB

because

- My machine spec is
	number of numa node: 2
	number of cpus:      8 (4CPU x2 node)
        total mem:           8GB (4GB x2 node)
        free mem:            about 5GB

- Then, 4.7GB x 16% ~= 880MB.
  So, Quicklist can use 800MB.

So, if following spec machine run that program

   CPUs: 64 (8cpu x 8node)
   Mem:  1TB (128GB x8node)

Then, quicklist can waste 300GB (= 1TB x 30%).  It is too large.

So, I don't like cache policies which is proportional to # of cpus.

My patch changes the number of caches
from:
   per-cpu-cache-amount = memory_on_node / 16
to
   per-cpu-cache-amount = memory_on_node / 16 / number_of_cpus_on_node.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Tested-by: NDavid Miller <davem@davemloft.net>
Acked-by: NMike Travis <travis@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Quicklists can consume several GB of memory.  We should provide a means of
monitoring this.

After this patch is applied, /proc/meminfo will output the following:

% cat /proc/meminfo

MemTotal:      7715392 kB
MemFree:       5401600 kB
Buffers:         80384 kB
Cached:         300800 kB
SwapCached:          0 kB
Active:         235584 kB
Inactive:       262656 kB
SwapTotal:     2031488 kB
SwapFree:      2031488 kB
Dirty:            3520 kB
Writeback:           0 kB
AnonPages:      117696 kB
Mapped:          38528 kB
Slab:          1589952 kB
SReclaimable:    23104 kB
SUnreclaim:    1566848 kB
PageTables:      14656 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
WritebackTmp:        0 kB
CommitLimit:   5889152 kB
Committed_AS:   393152 kB
VmallocTotal: 17592177655808 kB
VmallocUsed:     29056 kB
VmallocChunk: 17592177626432 kB
Quicklists:     130944 kB
HugePages_Total:     0
HugePages_Free:      0
HugePages_Rsvd:      0
HugePages_Surp:      0
Hugepagesize:    262144 kB
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During the use of a dev_cgroup, we should guarantee the corresponding
cgroup won't be deleted (i.e.  via rmdir).  This can be done through
css_get(&dev_cgroup->css), but here we can just get and use the dev_cgroup
under rcu_read_lock.

And also remove checking NULL dev_cgroup, it won't be NULL since a task
always belongs to a cgroup.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1. Check if virtual resolution fits into memory.
   Otherwise, Linux hangs during panning.
2. When selected use all available memory to
    maximize yres_virtual to speed up panning
   (previously also xres_virtual was increased).
3. Simplify memory restriction calculations.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We don't change pid_ns->child_reaper when the main thread of the
subnamespace init exits.  As Robert Rex <robert.rex@exasol.com> pointed
out this is wrong.

Yes, the re-parenting itself works correctly, but if the reparented task
exits it needs ->parent->nsproxy->pid_ns in do_notify_parent(), and if the
main thread is zombie its ->nsproxy was already cleared by
exit_task_namespaces().

Introduce the new function, find_new_reaper(), which finds the new
->parent for the re-parenting and changes ->child_reaper if needed.  Kill
the now unneeded exit_child_reaper().

Also move the changing of ->child_reaper from zap_pid_ns_processes() to
find_new_reaper(), this consolidates the games with ->child_reaper and
makes it stable under tasklist_lock.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11391Reported-by: NRobert Rex <robert.rex@exasol.com>
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

zap_pid_ns_processes() sets pid_ns->child_reaper = NULL, this is wrong.

Yes, we have already killed all tasks in this namespace, and sys_wait4()
doesn't see any child.  But this doesn't mean ->children list is empty, we
may have EXIT_DEAD tasks which are not visible to do_wait().  In that case
the subsequent forget_original_parent() will crash the kernel because it
will try to re-parent these tasks to the NULL reaper.

Even if there are no childs, it is not good that forget_original_parent()
uses reaper == NULL.

Change the code to set ->child_reaper = init_pid_ns.child_reaper instead.
We could use pid_ns->parent->child_reaper as well, I think this does not
really matter.  These EXIT_DEAD tasks are not visible to the new ->parent
after re-parenting, they will silently do release_task() eventually.

Note that we must change ->child_reaper, otherwise
forget_original_parent() will use reaper == father, and in that case we
will hit the (correct) BUG_ON(!list_empty(&father->children)).
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At91_mci is abusing dma_free_coherent(), which may not be called with IRQs
disabled.  I saw "mkfs.ext3" on an MMC card objecting voluminously as each
write completed:

 WARNING: at arch/arm/mm/consistent.c:368 dma_free_coherent+0x2c/0x224()
 [<c002726c>] (dump_stack+0x0/0x14) from [<c00387d4>] (warn_on_slowpath+0x4c/0x68)
 [<c0038788>] (warn_on_slowpath+0x0/0x68) from [<c0028768>] (dma_free_coherent+0x2c/0x224)
  r6:00008008 r5:ffc06000 r4:00000000
 [<c002873c>] (dma_free_coherent+0x0/0x224) from [<c01918ac>] (at91_mci_irq+0x374/0x420)
 [<c0191538>] (at91_mci_irq+0x0/0x420) from [<c0065d9c>] (handle_IRQ_event+0x2c/0x6c)
 ...

This bug has been around for a LONG time.  The MM warning is from late
2005, but the driver merged a year later ...  so I'm puzzled why nobody
noticed this before now.

The fix involves noting that this buffer shouldn't be DMA-coherent; it's
just used for normal DMA writes.  So replace it with standard kmalloc()
buffering and DMA mapping calls.

This is the quickie fix.  A better one would not rely on allocating large
bounce buffers.  (Note that dma_alloc_coherent could have failed too, but
that case was ignored...  kmalloc is a bit more likely to fail though.)
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NPierre Ossman <drzeus-mmc@drzeus.cx>
Cc: Andrew Victor <linux@maxim.org.za>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recent changes to tighten the check for UARTs that don't correctly
re-assert THRE (01c194d9: "serial 8250:
tighten test for using backup timer") caused problems when such a UART was
opened for the second time - the bug could only successfully be detected
at first initialization.  For users of this version of this particular
UART IP it is fatal.

This patch stores the information about the bug in the bugs field of the
port structure when the port is first started up so subsequent opens can
check this bit even if the test for the bug fails.

David Brownell: "My own exposure to this is that the UART on DaVinci
hardware, which TI allegedly derived from its original 16550 logic, has
periodically gone from working to unusable with the mainline 8250.c ...
and back and forth a bunch.  Currently it's "unusable", a regression from
some previous versions.  With this patch from Will, it's usable."
Signed-off-by: NWill Newton <will.newton@gmail.com>
Acked-by: NAlex Williamson <alex.williamson@hp.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

WARNING: vmlinux.o(.data+0x1f5c0): Section mismatch in reference from the variable contig_page_data to the variable .init.data:bootmem_node_data
The variable contig_page_data references
the variable __initdata bootmem_node_data
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
Signed-off-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Sean MacLennan <smaclennan@pikatech.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The exit function neglects to remove debugfs entries, leading to a BUG
on reload.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NRuss Dill <Russ.Dill@gmail.com>
Acked-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Dio write returns EIO when try_to_release_page fails because bh is
still referenced.

The patch

    commit 3f31fddf
    Author: Mingming Cao <cmm@us.ibm.com>
    Date:   Fri Jul 25 01:46:22 2008 -0700

        jbd: fix race between free buffer and commit transaction

was merged into 2.6.27-rc1, but I noticed that this patch is not enough
to fix the race.

I did fsstress test heavily to 2.6.27-rc1, and found that dio write still
sometimes got EIO through this test.

The patch above fixed race between freeing buffer(dio) and committing
transaction(jbd) but I discovered that there is another race, freeing
buffer(dio) and ext3/4_ordered_writepage.

: background_writeout()
     ->write_cache_pages()
       ->ext3_ordered_writepage()
     	   walk_page_buffers() -> take a bh ref
 	   block_write_full_page() -> unlock_page
		: <- end_page_writeback
                : <- race! (dio write->try_to_release_page fails)
      	   walk_page_buffers() ->release a bh ref

ext3_ordered_writepage holds bh ref and does unlock_page remaining
taking a bh ref, so this causes the race and failure of
try_to_release_page.

To fix this race, I used the approach of falling back to buffered
writes if try_to_release_page() fails on a page.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NHisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I have gotten to the root cause of the hugetlb badness I reported back on
August 15th.  My system has the following memory topology (note the
overlapping node):

            Node 0 Memory: 0x8000000-0x44000000
            Node 1 Memory: 0x0-0x8000000 0x44000000-0x80000000

setup_zone_migrate_reserve() scans the address range 0x0-0x8000000 looking
for a pageblock to move onto the MIGRATE_RESERVE list.  Finding no
candidates, it happily continues the scan into 0x8000000-0x44000000.  When
a pageblock is found, the pages are moved to the MIGRATE_RESERVE list on
the wrong zone.  Oops.

setup_zone_migrate_reserve() should skip pageblocks in overlapping nodes.
Signed-off-by: NAdam Litke <agl@us.ibm.com>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the location of the NTFS homepage in several files.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Re-enable IP when the MTU gets back to a valid size. 

This patch just checks if the in_dev is NULL on a NETDEV_CHANGEMTU event
and if MTU is valid (bigger than 68), then re-enable in_dev. 

Also a function that checks valid MTU size was created.
Signed-off-by: NBreno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>