Impact: fix incorrectly marked unstable TSC clock

Patch (commit 0d12cdd5 "sched: improve sched_clock() performance") has
a regression on one of the test systems here.

With the patch, I see:

 checking TSC synchronization [CPU#0 -> CPU#1]:
 Measured 28 cycles TSC warp between CPUs, turning off TSC clock.
 Marking TSC unstable due to check_tsc_sync_source failed

Whereas, without the patch syncs pass fine on all CPUs:

 checking TSC synchronization [CPU#0 -> CPU#1]: passed.

Due to this, TSC is marked unstable, when it is not actually unstable.
This is because syncs in check_tsc_wrap() goes away due to this commit.

As per the discussion on this thread, correct way to fix this is to add
explicit syncs as below?
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix guest kernel crash with CONFIG_XEN_SCRUB_PAGES=y

Jens noticed that scrub_page() has a buggy unmap of the wrong
thing. (virtual address instead of page)

Linus pointed out that the whole scrub_page() code is an unnecessary
reimplementation of clear_highpage() to begin with.

Just use clear_highpage() rather than reimplementing it poorly.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix es7000 build

  CC      arch/x86/kernel/es7000_32.o
arch/x86/kernel/es7000_32.c: In function find_unisys_acpi_oem_table:
arch/x86/kernel/es7000_32.c:255: error: implicit declaration of function acpi_get_table_with_size
arch/x86/kernel/es7000_32.c:261: error: implicit declaration of function early_acpi_os_unmap_memory
arch/x86/kernel/es7000_32.c: In function unmap_unisys_acpi_oem_table:
arch/x86/kernel/es7000_32.c:277: error: implicit declaration of function __acpi_unmap_table
make[1]: *** [arch/x86/kernel/es7000_32.o] Error 1

we applied one patch out of order...

| commit a73aaedd
| Author: Yinghai Lu <yhlu.kernel@gmail.com>
| Date:   Sun Sep 14 02:33:14 2008 -0700
|
|    x86: check dsdt before find oem table for es7000, v2
|
|    v2: use __acpi_unmap_table()

that patch need:

	x86: use early_ioremap in __acpi_map_table
	x86: always explicitly map acpi memory
	acpi: remove final __acpi_map_table mapping before setting acpi_gbl_permanent_mmap
	acpi/x86: introduce __apci_map_table, v4

submitted to the ACPI tree but not upstream yet.

fix it until those patches applied, need to revert this one
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Fix a problem where ds_request() returned an error without releasing the
ds lock.
Reported-by: Stephane Eranian <eranian@gmail.com>
Signed-off-by: Markus Metzger <markus.t.metzger@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: build/boot fix for x86/Voyager

This change:

| commit 3d442233
| Author: Jens Axboe <jens.axboe@oracle.com>
| Date:   Thu Jun 26 11:21:34 2008 +0200
|
|     Add generic helpers for arch IPI function calls

didn't wire up the voyager smp call function correctly, so do that
here.  Also make CONFIG_USE_GENERIC_SMP_HELPERS a def_bool y again,
since we now use the generic helpers for every x86 architecture.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <Jens.Axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

a new file was accidentally added to include/asm-x86;
move it to the new arch/x86/include/asm location
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: optimize sched_clock() a bit
  sched: improve sched_clock() performance

Merge branch 'oprofile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'oprofile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  oprofile: Fix p6 counter overflow check
  Cell OProfile: Incorrect local array size in activate spu profiling function
  Revert "Cell OProfile: Incorrect local array size in activate spu profiling function"
  oprofile: fix memory ordering
  Cell OProfile: Incorrect local array size in activate spu profiling function
  Change UTF8 chars in Kconfig help text about Oprofile AMD barcelona

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
  Staging: make usbip depend on CONFIG_NET
  Staging: only build the tree if we really want to

Fix the __pfn_to_page(pfn) macro so that it doesn't evaluate its
argument twice in the CONFIG_DISCONTIGMEM=y case, because 'pfn' may
be a result of a funtion call having side effects.

For example, the hibernation code applies pfn_to_page(pfn) to the
result of a function returning the pfn corresponding to the next set
bit in a bitmap and the current bit position is modified on each
call.  This leads to "interesting" failures for CONFIG_DISCONTIGMEM=y
due to the current behavior of __pfn_to_page(pfn).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sched_clock() uses cycles_2_ns() needlessly - which is an irq-disabling
variant of __cycles_2_ns().

Most of the time sched_clock() is called with irqs disabled already.
The few places that call it with irqs enabled need to be updated.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

in scheduler-intense workloads native_read_tsc() overhead accounts for
20% of the system overhead:

 659567 system_call                              41222.9375
 686796 schedule                                 435.7843
 718382 __switch_to                              665.1685
 823875 switch_mm                                4526.7857
 1883122 native_read_tsc                          55385.9412
 9761990 total                                      2.8468

this is large part due to the rdtsc_barrier() that is done before
and after reading the TSC.

But sched_clock() is not a precise clock in the GTOD sense, using such
barriers is completely pointless. So remove the barriers and only use
them in vget_cycles().

This improves lat_ctx performance by about 5%.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Thanks to Randy Dunlap for finding this problem.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This Kconfig change allows the common 'make allmodconfig' and
'make allyesconfig' build options to skip the staging tree, which is
probably what you want to have happen anyway.

This makes the linux-next developer's life a lot easier so he doesn't
have to worry about changes that break the staging tree, that's for me
to worry about...
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Merge branch 'oprofile-for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into x86/urgent

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Reserve elfcorehdr memory in CONFIG_CRASH_DUMP
  [IA64] fix boot panic caused by offline CPUs
  [IA64] reorder Kconfig options to match x86
  [IA64] Build VT-D iommu support into generic kernel
  [IA64] remove dead BIO_VMERGE_BOUNDARY definition
  [IA64] remove duplicated #include from pci-dma.c
  [IA64] use common header for software IO/TLB
  [IA64] fix the difference between node_mem_map and node_start_pfn
  [IA64] Add error_recovery_info field to SAL section header
  [IA64] Add UV watchlist support.
  [IA64] Simplify SGI uv vs. sn2 driver issues

IA64 kdump kernel failed to initialize /proc/vmcore in 2.6.28-rc2.
A bug was introduced in this patch commit:

  d9a9855d
  always reserve elfcore header memory in crash kernel

The problem was that the call to reserve_elfcorehdr() should be placed
in CONFIG_CRASH_DUMP rather than in CONFIG_CRASH_KERNEL, which does
not exist.
Signed-off-by: Jay Lan <jlan@sgi.com>
Acked-by: Simon Hormon <horms@verge.net.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: fix range check on mmapped sysfs resource files
  PCI: remove excess kernel-doc notation
  PCI: annotate return value of pci_ioremap_bar with __iomem
  PCI: fix VPD limit quirk for Broadcom 5708S

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, xen: fix use of pgd_page now that it really does return a page

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fine-tune SD_SIBLING_INIT
  sched: fine-tune SD_MC_INIT
  sched: fix memory leak in a failure path
  sched: fix a bug in sched domain degenerate

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  xen: make sure stray alias mappings are gone before pinning
  vmap: cope with vm_unmap_aliases before vmalloc_init()

Fix the counter overflow check for CPUs with counter width > 32

I had a similar change in a different patch that I didn't submit
and I didn't notice the problem earlier because it was always
tested together.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>

This triggers false bug reports as it does a bogus kmalloc with locks held
but is never really compiled into the kernel.

Closes #8329
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As we've lost our trivial maintainer for the moment I'll send this
directly. Only touches a comment
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: add checksum calculation when clearing UNINIT flag in ext4_new_inode
  ext4: Mark the buffer_heads as dirty and uptodate after prepare_write
  ext4: calculate journal credits correctly
  ext4: wait on all pending commits in ext4_sync_fs()
  ext4: Convert to host order before using the values.
  ext4: fix missing ext4_unlock_group in error path
  jbd2: deregister proc on failure in jbd2_journal_init_inode
  jbd2: don't give up looking for space so easily in __jbd2_log_wait_for_space
  jbd: don't give up looking for space so easily in __log_wait_for_space

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 <mingo@elte.hu>

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 <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

 # *DOCUMENTATION*

When initializing an uninitialized block group in ext4_new_inode(),
its block group checksum must be re-calculated.  This fixes a race
when several threads try to allocate a new inode in an UNINIT'd group.

There is some question whether we need to be initializing the block
bitmap in ext4_new_inode() at all, but for now, if we are going to
init the block group, let's eliminate the race.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

We need to make sure we mark the buffer_heads as dirty and uptodate
so that block_write_full_page write them correctly.

This fixes mmap corruptions that can occur in low memory situations.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Xen requires that all mappings of pagetable pages are read-only, so
that they can't be updated illegally.  As a result, if a page is being
turned into a pagetable page, we need to make sure all its mappings
are RO.

If the page had been used for ioremap or vmalloc, it may still have
left over mappings as a result of not having been lazily unmapped.
This change makes sure we explicitly mop them all up before pinning
the page.

Unlike aliases created by kmap, the there can be vmalloc aliases even
for non-high pages, so we must do the flush unconditionally.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Linux Memory Management List <linux-mm@kvack.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Xen can end up calling vm_unmap_aliases() before vmalloc_init() has
been called.  In this case its safe to make it a simple no-op.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Linux Memory Management List <linux-mm@kvack.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix rare memory leak in the sched-domains manual reconfiguration code

In the failure path, rd is not attached to a sched domain,
so it causes a leak.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: re-add incorrectly eliminated sched domain layers

(1) on i386 with SCHED_SMT and SCHED_MC enabled
	# mount -t cgroup -o cpuset xxx /mnt
	# echo 0 > /mnt/cpuset.sched_load_balance
	# mkdir /mnt/0
	# echo 0 > /mnt/0/cpuset.cpus
	# dmesg
	CPU0 attaching sched-domain:
	 domain 0: span 0 level CPU
	  groups: 0

(2) on i386 with SCHED_MC enabled but SCHED_SMT disabled
	# same with (1)
	# dmesg
	CPU0 attaching NULL sched-domain.

The bug is that some sched domains may be skipped unintentionally when
degenerating (optimizing) sched domains.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  net: Fix recursive descent in __scm_destroy().
  iwl3945: fix deadlock on suspend
  iwl3945: do not send scan command if channel count zero
  iwl3945: clear scanning bits upon failure
  ath5k: correct handling of rx status fields
  zd1211rw: Add 2 device IDs
  Fix logic error in rfkill_check_duplicity
  iwlagn: avoid sleep in softirq context
  iwlwifi: clear scanning bits upon failure
  Revert "ath5k: honor FIF_BCN_PRBRESP_PROMISC in STA mode"
  tcp: Fix recvmsg MSG_PEEK influence of blocking behavior.
  netfilter: netns ct: walk netns list under RTNL
  ipv6: fix run pending DAD when interface becomes ready
  net/9p: fix printk format warnings
  net: fix packet socket delivery in rx irq handler
  xfrm: Have af-specific init_tempsel() initialize family field of temporary selector

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  Revert "x86: default to reboot via ACPI"
  x86: align DirectMap in /proc/meminfo
  AMD IOMMU: fix lazy IO/TLB flushing in unmap path
  x86: add smp_mb() before sending INVALIDATE_TLB_VECTOR
  x86: remove VISWS and PARAVIRT around NR_IRQS puzzle
  x86: mention ACPI in top-level Kconfig menu
  x86: size NR_IRQS on 32-bit systems the same way as 64-bit
  x86: don't allow nr_irqs > NR_IRQS
  x86/docs: remove noirqbalance param docs
  x86: don't use tsc_khz to calculate lpj if notsc is passed
  x86, voyager: fix smp_intr_init() compile breakage
  AMD IOMMU: fix detection of NP capable IOMMUs

* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] xsc3: fix xsc3_l2_inv_range
  [ARM] mm: fix page table initialization
  [ARM] fix naming of MODULE_START / MODULE_END
  ARM: OMAP: Fix define for twl4030 irqs
  ARM: OMAP: Fix get_irqnr_and_base to clear spurious interrupt bits
  ARM: OMAP: Fix debugfs_create_*'s error checking method for arm/plat-omap
  ARM: OMAP: Fix compiler warnings in gpmc.c
  [ARM] fix VFP+softfloat binaries

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  ieee1394: dv1394: fix possible deadlock in multithreaded clients
  ieee1394: raw1394: fix possible deadlock in multithreaded clients
  ieee1394: struct device - replace bus_id with dev_name(), dev_set_name()
  firewire: struct device - replace bus_id with dev_name(), dev_set_name()

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Block: use round_jiffies_up()
  Add round_jiffies_up and related routines
  block: fix __blkdev_get() for removable devices
  generic-ipi: fix the smp_mb() placement
  blk: move blk_delete_timer call in end_that_request_last
  block: add timer on blkdev_dequeue_request() not elv_next_request()
  bio: define __BIOVEC_PHYS_MERGEABLE
  block: remove unused ll_new_mergeable()

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] SAM9 watchdog - supported on all SAM9 and CAP9 processors
  [WATCHDOG] SAM9 watchdog - update for moved headers