Commit graph

211 commits

Author SHA1 Message Date
Yinghai Lu
8b8e8c1bf7 x86: remove irqbalance in kernel for 32 bit
This has been deprecated for years, the user space irqbalanced utility
works better with numa, has configurable policies, etc...

Signed-off-by: Yinghai Lu <yhlu.kernel@gmai.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:52 +02:00
Yinghai Lu
08678b0841 generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[]
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.

Preallocate 32 irq_desc, and irq_desc() will try to get more.

( No change in functionality is expected anywhere, except the odd build
  failure where we missed a code site or where a crossing commit itroduces
  new irq_desc[] usage. )

v2: according to Eric, change get_irq_desc() to irq_desc()

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:29 +02:00
Yinghai Lu
6da55c3e8d x86: enable dyn_array support
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:04 +02:00
David Woodhouse
e758936e02 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:

	include/asm-x86/statfs.h
2008-10-13 17:13:56 +01:00
Ingo Molnar
8daf14cf56 Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', 'x86/memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2 2008-10-12 15:50:02 +02:00
Ingo Molnar
a9b9e81c91 Merge branch 'linus' into x86/memory-corruption-check 2008-10-12 15:05:39 +02:00
Ingo Molnar
d84705969f Merge branch 'x86/apic' into x86-v28-for-linus-phase4-B
Conflicts:
	arch/x86/kernel/apic_32.c
	arch/x86/kernel/apic_64.c
	arch/x86/kernel/setup.c
	drivers/pci/intel-iommu.c
	include/asm-x86/cpufeature.h
	include/asm-x86/dma-mapping.h
2008-10-11 20:17:36 +02:00
Ingo Molnar
725c25819e Merge branches 'core/iommu', 'x86/amd-iommu' and 'x86/iommu' into x86-v28-for-linus-phase3-B
Conflicts:
	arch/x86/kernel/pci-gart_64.c
	include/asm-x86/dma-mapping.h
2008-10-10 19:47:12 +02:00
Ingo Molnar
e496e3d645 Merge branches 'x86/alternatives', 'x86/cleanups', 'x86/commandline', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/exports', 'x86/fpu', 'x86/gart', 'x86/idle', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/oprofile', 'x86/paravirt', 'x86/reboot', 'x86/sparse-fixes', 'x86/tsc', 'x86/urgent' and 'x86/vmalloc' into x86-v28-for-linus-phase1 2008-10-06 18:17:07 +02:00
Yinghai Lu
2ffb3501f6 x86: change MTRR_SANITIZER to def_bool y
This option has been added in v2.6.26 as a default-disabled
feature and went through several revisions since then.

The feature fixes a wide range of MTRR setup problems that BIOSes
leave us with: slow system, slow Xorg, slow system when adding lots
of RAM, etc., so we want to enable it by default for v2.6.28.

See:

  [Bug 10508] Upgrade to 4GB of RAM messes up MTRRs
  http://bugzilla.kernel.org/show_bug.cgi?id=10508

and the test results in:

   http://lkml.org/lkml/2008/9/29/273

1. hpa
reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
reg01: base=0x13c000000 (5056MB), size=  64MB: uncachable, count=1
reg02: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg03: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
reg04: base=0xbf700000 (3063MB), size=   1MB: uncachable, count=1
reg05: base=0xbf800000 (3064MB), size=   8MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 128M        num_reg: 6      lose RAM: 0M
range0: 0000000000000000 - 00000000c0000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
hole: 00000000bf700000 - 00000000c0000000
Setting variable MTRR 2, base: 3063MB, range: 1MB, type UC
Setting variable MTRR 3, base: 3064MB, range: 8MB, type UC
range0: 0000000100000000 - 0000000140000000
Setting variable MTRR 4, base: 4096MB, range: 1024MB, type WB
hole: 000000013c000000 - 0000000140000000
Setting variable MTRR 5, base: 5056MB, range: 64MB, type UC

2. Dylan Taft
reg00: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg01: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
reg02: base=0x120000000 (4608MB), size= 256MB: write-back, count=1
reg03: base=0xd0000000 (3328MB), size= 256MB: uncachable, count=1
reg04: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
reg05: base=0xc7e00000 (3198MB), size=   2MB: uncachable, count=1
reg06: base=0xc8000000 (3200MB), size= 128MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 4M  num_reg: 6      lose RAM: 0M
range0: 0000000000000000 - 00000000c8000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
Setting variable MTRR 2, base: 3072MB, range: 128MB, type WB
hole: 00000000c7e00000 - 00000000c8000000
Setting variable MTRR 3, base: 3198MB, range: 2MB, type UC
rangeX: 0000000100000000 - 0000000130000000
Setting variable MTRR 4, base: 4096MB, range: 512MB, type WB
Setting variable MTRR 5, base: 4608MB, range: 256MB, type WB

3. Gabriel
reg00: base=0xd0000000 (3328MB), size= 256MB: uncachable, count=1
reg01: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
reg02: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg03: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
reg04: base=0x120000000 (4608MB), size= 128MB: write-back, count=1
reg05: base=0x128000000 (4736MB), size=  64MB: write-back, count=1
reg06: base=0xcf600000 (3318MB), size=   2MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 16M         num_reg: 7      lose RAM: 0M
range0: 0000000000000000 - 00000000d0000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
Setting variable MTRR 2, base: 3072MB, range: 256MB, type WB
hole: 00000000cf600000 - 00000000cf800000
Setting variable MTRR 3, base: 3318MB, range: 2MB, type UC
rangeX: 0000000100000000 - 000000012c000000
Setting variable MTRR 4, base: 4096MB, range: 512MB, type WB
Setting variable MTRR 5, base: 4608MB, range: 128MB, type WB
Setting variable MTRR 6, base: 4736MB, range: 64MB, type WB

4. Mika Fischer
reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
reg01: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1
reg02: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
reg03: base=0xbf700000 (3063MB), size= 1MB: uncachable, count=1
reg04: base=0xbf800000 (3064MB), size= 8MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 16M         num_reg: 5      lose RAM: 0M
range0: 0000000000000000 - 00000000c0000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
hole: 00000000bf700000 - 00000000c0000000
Setting variable MTRR 2, base: 3063MB, range: 1MB, type UC
Setting variable MTRR 3, base: 3064MB, range: 8MB, type UC
rangeX: 0000000100000000 - 0000000140000000
Setting variable MTRR 4, base: 4096MB, range: 1024MB, type WB

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-01 08:35:44 +02:00
Ingo Molnar
e6aa0f07cb Merge commit 'v2.6.27-rc7' into x86/microcode 2008-09-24 10:31:34 +02:00
Dmitry Adamushko
18dbc91605 x86: moved microcode.c to microcode_intel.c
Combine both generic and arch-specific parts of microcode into a
single module (arch-specific parts are config-dependent).

Also while we are at it, move arch-specific parts from microcode.h
into their respective arch-specific .c files.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: "Peter Oruba" <peter.oruba@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 12:21:42 +02:00
Joerg Roedel
a80dc3e0e0 AMD IOMMU: add MSI interrupt support
The AMD IOMMU can generate interrupts for various reasons. This patch
adds the basic interrupt enabling infrastructure to the driver.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19 12:59:15 +02:00
Ingo Molnar
5e51900be6 Merge commit 'v2.6.27-rc6' into x86/cleanups 2008-09-19 09:15:50 +02:00
Ingo Molnar
fc38151947 x86: add X86_RESERVE_LOW_64K
This bugzilla:

  http://bugzilla.kernel.org/show_bug.cgi?id=11237

Documents a wide range of systems where the BIOS utilizes the first
64K of physical memory during suspend/resume and other hardware events.

Currently we reserve this memory on all AMI and Phoenix BIOS systems.
Life is too short to hunt subtle memory corruption problems like this,
so we try to be robust by default.

Still, allow this to be overriden: allow users who want that first 64K
of memory to be available to the kernel disable the quirk, via
CONFIG_X86_RESERVE_LOW_64K=n.

Also, allow the early reservation to overlap with other
early reservations.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-16 12:16:07 +02:00
Alexey Dobriyan
b899219572 x86: simpler SYSVIPC_COMPAT definition
X86_64 part is entirely redundant.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 14:57:15 +02:00
Alexey Dobriyan
9c0bbee8a6 seccomp: drop now bogus dependency on PROC_FS
seccomp is prctl(2)-driven now.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-09 09:09:51 +02:00
Jeremy Fitzhardinge
c885df50f5 x86: default corruption check to off, but put parameter default in Kconfig
Default the low memory corruption check to off, but make the default setting of
the memory_corruption_check kernel parameter a config parameter.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-07 17:40:02 +02:00
Jeremy Fitzhardinge
9f077871ce x86: clean up memory corruption check and add more kernel parameters
The corruption check is enabled in Kconfig by default, but disabled at runtime.

This patch adds several kernel parameters to control the corruption
check's behaviour; these are documented in kernel-parameters.txt.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-07 17:40:01 +02:00
Jeremy Fitzhardinge
5394f80f92 x86: check for and defend against BIOS memory corruption
Some BIOSes have been observed to corrupt memory in the low 64k.  This
change:
 - Reserves all memory which does not have to be in that area, to
   prevent it from being used as general memory by the kernel.  Things
   like the SMP trampoline are still in the memory, however.
 - Clears the reserved memory so we can observe changes to it.
 - Adds a function check_for_bios_corruption() which checks and reports on
   memory becoming unexpectedly non-zero.  Currently it's called in the
   x86 fault handler, and the powermanagement debug output.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-07 17:39:59 +02:00
David Woodhouse
e17c6d5616 Introduce HAVE_AOUT symbol to remove hard-coded arch list for BINFMT_AOUT
HAVE_AOUT doesn't quite do the same thing as the recently removed
ARCH_SUPPORTS_AOUT config option. That was set even on platforms where
binfmt_aout isn't supported, although it's not entirely clear why.

So it's best just to introduce a new symbol, handled consistently with
other similar HAVE_xxx symbols; with a simple 'select' in the arch Kconfig.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-09-06 19:30:22 +01:00
David Woodhouse
6b213e1bc2 Remove redundant CONFIG_ARCH_SUPPORTS_AOUT
We don't need this any more; arguably we never really did.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-09-06 19:30:20 +01:00
Ingo Molnar
616ad8c442 Merge branch 'linus' into x86/defconfig 2008-09-05 18:56:57 +02:00
Ingo Molnar
28c3cfd5fb Merge branch 'linus' into x86/tracehook 2008-09-05 17:53:05 +02:00
Linus Torvalds
d25e26b61d [x86] Clean up MAXSMP Kconfig, and limit NR_CPUS to 512
This fixes a regression that was indirectly caused by commit
1184dc2ffe ("x86: modify Kconfig to allow
up to 4096 cpus").

Allowing 4k CPU's is not practical at this time, because we still have a
number of places that have several 'cpumask_t's on the stack, and a
4k-bit cpumask is 512 bytes of stack-space for each such variable.  This
literally caused functions like 'smp_call_function_mask' to have a 2.5kB
stack frame, and several functions to have 2kB stackframes.

With an 8kB stack total, smashing the stack was simply much too likely.
At least bugzilla entry

	http://bugzilla.kernel.org/show_bug.cgi?id=11342

was due to this.

The earlier commit to not inline load_module() into sys_init_module()
fixed the particular symptoms of this that Alan Brunelle saw in that
bugzilla entry, but the huge stack waste by cpumask_t's was the more
direct cause.

Some day we'll have allocation helpers that allocate large CPU masks
dynamically, but in the meantime we simply cannot allow cpumasks this
large.

Cc: Alan D. Brunelle <Alan.Brunelle@hp.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-25 14:15:38 -07:00
Ingo Molnar
470fba7ebe Merge branch 'linus' into x86/doc 2008-08-21 13:28:24 +02:00
Ingo Molnar
04197c83b3 Merge branch 'linus' into x86/tracehook
Conflicts:
	arch/x86/Kconfig

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 17:07:34 +02:00
Tim Bird
516cbf3730 x86, bootup: add built-in kernel command line for x86 (v2)
Allow x86 to support a built-in kernel command line.  The built-in
command line can override the one provided by the boot loader, for
those cases where the boot loader is broken or it is difficult
to change the command line in the the boot loader.

H. Peter Anvin wrote:
> Ingo Molnar wrote:
>> Best would be to make it really apparent in the code that nothing
>> changes if this config option is not set. Preferably there should be
>> no extra code at all in that case.
>>
>
> I would like to see this:
[...Nested ifdefs...]

OK. This version changes absolutely nothing if CONFIG_CMDLINE_BOOL is not
set (the default).  Also, no space is appended even when CONFIG_CMDLINE_BOOL
is set, but the builtin string is empty.  This is less sloppy all the way
around, IMHO.

Note that I use the same option names as on other arches for
this feature.

[ mingo@elte.hu: build fix ]

Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 16:10:37 +02:00
Pavel Machek
04b69447f7 arch/x86/Kconfig: clean up, experimental adjustement
Adjust experimental tags in Kconfig, update config to notice that
i386/x86_64 is now single architecture.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 14:06:54 +02:00
Ingo Molnar
51ca3c6791 Merge branch 'linus' into x86/core
Conflicts:
	arch/x86/kernel/genapic_64.c
	include/asm-x86/kvm_host.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-14 14:58:01 +02:00
Rusty Russell
912985dce4 mm: Make generic weak get_user_pages_fast and EXPORT_GPL it
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.

Export the symbol to modules so lguest can use it.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-12 17:52:53 +10:00
Jeff Chua
99809963c9 x86: make sparsemem more available
With CONFIG_X86_PC, I can set CONFIG_SPARSEMEM=y.

With CONFIG_X86_GENERICARCH, CONFIG_SPARSEMEM depends on CONFIG_NUMA.

I'm using the patch below to enable sparsemem instead of flatmem.
System booted and is running.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 22:01:57 +02:00
Dimitri Sivanich
7c13e6a3d1 x86: remove EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU
This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU
on the x86 architecture.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11 18:29:56 +02:00
Ingo Molnar
15dd859cac Merge commit 'v2.6.27-rc1' into x86/core
Conflicts:

	include/asm-x86/dma-mapping.h
	include/asm-x86/namei.h
	include/asm-x86/uaccess.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-30 19:33:48 +02:00
Ingo Molnar
3825c9e8d0 Merge commit 'v2.6.27-rc1' into x86/microcode
Conflicts:

	arch/x86/kernel/microcode.c

Manual resolutions:

	arch/x86/kernel/microcode_amd.c
	arch/x86/kernel/microcode_intel.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-29 11:54:24 +02:00
Ingo Molnar
cb28a1bbdb Merge branch 'linus' into core/generic-dma-coherent
Conflicts:

	arch/x86/Kconfig

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-29 00:07:55 +02:00
Peter Oruba
80cc9f1020 x86: AMD microcode patch loading support
This patch introduces microcode patch loading for AMD
processors. It is based on previous corresponding work
for Intel processors.

It hooks into the general patch loading module. Main
difference is that a container file format is used to hold
all patch data for multiple processors as well as an
equivalent CPU table, which comes seperately, as opposed
to Intel's microcode patching solution.

Kconfig and Makefile have been changed provice config
and build option for new source file.

Signed-off-by: Peter Oruba <peter.oruba@amd.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28 19:57:58 +02:00
Peter Oruba
8d86f390d9 x86: major refactoring
Refactored code by introducing a two-module solution.

There is one general module in which vendor specific modules can hook into.
However, that is exclusive, there is only one vendor specific module
allowed at a time. A CPU vendor check makes sure only the correct
module for the underlying system gets called.

Functinally in terms of patch loading itself there are no changes. This
refactoring provides a basis for future implementations of other vendors'
patch loaders.

Signed-off-by: Peter Oruba <peter.oruba@amd.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28 19:57:57 +02:00
Randy Dunlap
7225e75144 documentation: move mtrr.txt to Doc/x86/ subdir
Move mtrr.txt to the Documentation/x86/ subdirectory.
Add 00-INDEX to the Documentation/x86/ subdirectory.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28 14:46:49 +02:00
Roland McGrath
99bbc4b1e6 x86: tracehook: CONFIG_HAVE_ARCH_TRACEHOOK
The x86 arch code has all the prerequisites, so set HAVE_ARCH_TRACEHOOK.

Signed-off-by: Roland McGrath <roland@redhat.com>
2008-07-26 14:38:06 -07:00
Linus Torvalds
fb3b806144 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, AMD IOMMU: include amd_iommu_last_bdf in device initialization
  x86: fix IBM Summit based systems' phys_cpu_present_map on 32-bit kernels
  x86, RDC321x: remove gpio.h complications
  x86, RDC321x: add to mach-default
  crashdump: fix undefined reference to `elfcorehdr_addr'
  flag parameters: fix compile error of sys_epoll_create1
2008-07-26 13:25:05 -07:00
Nick Piggin
8174c430e4 x86: lockless get_user_pages_fast()
Implement get_user_pages_fast without locking in the fastpath on x86.

Do an optimistic lockless pagetable walk, without taking mmap_sem or any
page table locks or even mmap_sem.  Page table existence is guaranteed by
turning interrupts off (combined with the fact that we're always looking
up the current mm, means we can do the lockless page table walk within the
constraints of the TLB shootdown design).  Basically we can do this
lockless pagetable walk in a similar manner to the way the CPU's pagetable
walker does not have to take any locks to find present ptes.

This patch (combined with the subsequent ones to convert direct IO to use
it) was found to give about 10% performance improvement on a 2 socket 8
core Intel Xeon system running an OLTP workload on DB2 v9.5

 "To test the effects of the patch, an OLTP workload was run on an IBM
  x3850 M2 server with 2 processors (quad-core Intel Xeon processors at
  2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel.  Comparing
  runs with and without the patch resulted in an overall performance
  benefit of ~9.8%.  Correspondingly, oprofiles showed that samples from
  __up_read and __down_read routines that is seen during thread contention
  for system resources was reduced from 2.8% down to .05%.  Monitoring the
  /proc/vmstat output from the patched run showed that the counter for
  fast_gup contained a very high number while the fast_gup_slow value was
  zero."

(fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a
counter we had for the number of times the slowpath was invoked).

The main reason for the improvement is that DB2 has multiple threads each
issuing direct-IO.  Direct-IO uses get_user_pages, and thus the threads
contend the mmap_sem cacheline, and can also contend on page table locks.

I would anticipate larger performance gains on larger systems, however I
think DB2 uses an adaptive mix of threads and processes, so it could be
that thread contention remains pretty constant as machine size increases.
In which case, we stuck with "only" a 10% gain.

The downside of using get_user_pages_fast is that if there is not a pte
with the correct permissions for the access, we end up falling back to
get_user_pages and so the get_user_pages_fast is a bit of extra work.
However this should not be the common case in most performance critical
code.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: Kconfig fix]
[akpm@linux-foundation.org: Makefile fix/cleanup]
[akpm@linux-foundation.org: warning fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:06 -07:00
Huang Ying
89081d17f7 kexec jump: save/restore device state
This patch implements devices state save/restore before after kexec.

This patch together with features in kexec_jump patch can be used for
following:

- A simple hibernation implementation without ACPI support.  You can kexec a
  hibernating kernel, save the memory image of original system and shutdown
  the system.  When resuming, you restore the memory image of original system
  via ordinary kexec load then jump back.

- Kernel/system debug through making system snapshot.  You can make system
  snapshot, jump back, do some thing and make another system snapshot.

- Cooperative multi-kernel/system.  With kexec jump, you can switch between
  several kernels/systems quickly without boot process except the first time.
  This appears like swap a whole kernel/system out/in.

- A general method to call program in physical mode (paging turning
  off). This can be used to invoke BIOS code under Linux.

The following user-space tools can be used with kexec jump:

- kexec-tools needs to be patched to support kexec jump. The patches
  and the precompiled kexec can be download from the following URL:
       source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10

- makedumpfile with patches are used as memory image saving tool, it
  can exclude free pages from original kernel memory image file. The
  patches and the precompiled makedumpfile can be download from the
  following URL:
       source: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-src_cvs_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-patches_cvs_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile_cvs_kh10

- An initramfs image can be used as the root file system of kexeced
  kernel. An initramfs image built with "BuildRoot" can be downloaded
  from the following URL:
       initramfs image: http://khibernation.sourceforge.net/download/release_v10/initramfs/rootfs_cvs_kh10.gz
  All user space tools above are included in the initramfs image.

Usage example of simple hibernation:

1. Compile and install patched kernel with following options selected:

CONFIG_X86_32=y
CONFIG_RELOCATABLE=y
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
CONFIG_PM=y
CONFIG_HIBERNATION=y
CONFIG_KEXEC_JUMP=y

2. Build an initramfs image contains kexec-tool and makedumpfile, or
   download the pre-built initramfs image, called rootfs.gz in
   following text.

3. Prepare a partition to save memory image of original kernel, called
   hibernating partition in following text.

4. Boot kernel compiled in step 1 (kernel A).

5. In the kernel A, load kernel compiled in step 1 (kernel B) with
   /sbin/kexec. The shell command line can be as follow:

   /sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000
     --mem-max=0xffffff --initrd=rootfs.gz

6. Boot the kernel B with following shell command line:

   /sbin/kexec -e

7. The kernel B will boot as normal kexec. In kernel B the memory
   image of kernel A can be saved into hibernating partition as
   follow:

   jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='`
   echo $jump_back_entry > kexec_jump_back_entry
   cp /proc/vmcore dump.elf

   Then you can shutdown the machine as normal.

8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as
   root file system.

9. In kernel C, load the memory image of kernel A as follow:

   /sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf

10. Jump back to the kernel A as follow:

   /sbin/kexec -e

   Then, kernel A is resumed.

Implementation point:

To support jumping between two kernels, before jumping to (executing)
the new kernel and jumping back to the original kernel, the devices
are put into quiescent state, and the state of devices and CPU is
saved. After jumping back from kexeced kernel and jumping to the new
kernel, the state of devices and CPU are restored accordingly. The
devices/CPU state save/restore code of software suspend is called to
implement corresponding function.

Known issues:

- Because the segment number supported by sys_kexec_load is limited,
  hibernation image with many segments may not be load. This is
  planned to be eliminated by adding a new flag to sys_kexec_load to
  make a image can be loaded with multiple sys_kexec_load invoking.

Now, only the i386 architecture is supported.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:04 -07:00
Huang Ying
3ab8352137 kexec jump
This patch provides an enhancement to kexec/kdump.  It implements the
following features:

- Backup/restore memory used by the original kernel before/after
  kexec.

- Save/restore CPU state before/after kexec.

The features of this patch can be used as a general method to call program in
physical mode (paging turning off).  This can be used to call BIOS code under
Linux.

kexec-tools needs to be patched to support kexec jump. The patches and
the precompiled kexec can be download from the following URL:

       source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10

Usage example of calling some physical mode code and return:

1. Compile and install patched kernel with following options selected:

CONFIG_X86_32=y
CONFIG_KEXEC=y
CONFIG_PM=y
CONFIG_KEXEC_JUMP=y

2. Build patched kexec-tool or download the pre-built one.

3. Build some physical mode executable named such as "phy_mode"

4. Boot kernel compiled in step 1.

5. Load physical mode executable with /sbin/kexec. The shell command
   line can be as follow:

   /sbin/kexec --load-preserve-context --args-none phy_mode

6. Call physical mode executable with following shell command line:

   /sbin/kexec -e

Implementation point:

To support jumping without reserving memory.  One shadow backup page (source
page) is allocated for each page used by kexeced code image (destination
page).  When do kexec_load, the image of kexeced code is loaded into source
pages, and before executing, the destination pages and the source pages are
swapped, so the contents of destination pages are backupped.  Before jumping
to the kexeced code image and after jumping back to the original kernel, the
destination pages and the source pages are swapped too.

C ABI (calling convention) is used as communication protocol between
kernel and called code.

A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
indicate that the loaded kernel image is used for jumping back.

Now, only the i386 architecture is supported.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:04 -07:00
Ingo Molnar
10d3285d0b Merge branch 'x86/urgent' into x86/core
Conflicts:

	include/asm-x86/gpio.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 16:30:19 +02:00
Ingo Molnar
6dec3a10a7 Merge branch 'x86/x2apic' into x86/core
Conflicts:

	include/asm-x86/i8259.h
	include/asm-x86/msidef.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 16:29:23 +02:00
Ingo Molnar
1f972768a1 x86, RDC321x: add to mach-default
first step to add RDC321x support to the default PC architecture.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 13:51:46 +02:00
Michael Buesch
7444a72eff gpiolib: allow user-selection
This patch adds functionality to the gpio-lib subsystem to make it
possible to enable the gpio-lib code even if the architecture code didn't
request to get it built in.

The archtitecture code does still need to implement the gpiolib accessor
functions in its asm/gpio.h file.  This patch adds the implementations for
x86 and PPC.

With these changes it is possible to run generic GPIO expansion cards on
every architecture that implements the trivial wrapper functions.  Support
for more architectures can easily be added.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:30 -07:00
Johannes Berg
58340a07c1 introduce HAVE_EFFICIENT_UNALIGNED_ACCESS Kconfig symbol
In many cases, especially in networking, it can be beneficial to know at
compile time whether the architecture can do unaligned accesses efficiently.
This patch introduces a new Kconfig symbol

	HAVE_EFFICIENT_UNALIGNED_ACCESS

for that purpose and adds it to the powerpc and x86 architectures.  Also add
some documentation about alignment and networking, and especially one intended
use of this symbol.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Ingo Molnar <mingo@elte.hu> [x86 architecture part]
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:27 -07:00
Ingo Molnar
10a010f695 Merge branch 'linus' into x86/x2apic
Conflicts:

	drivers/pci/dmar.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-25 13:08:16 +02:00