Commit Graph

224 Commits

Author SHA1 Message Date
Jan Beulich 4481374ce8 mm: replace various uses of num_physpages by totalram_pages
Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally includes (perhaps a huge amount
of) non-RAM pages.  The amount of what actually is usable as storage
should instead be used as a basis here.

Some of the calculations (i.e.  those not intending to use high memory)
should likely even use (totalram_pages - totalhigh_pages).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:38 -07:00
Linus Torvalds ab86e5765d Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
  debugfs: Modify default debugfs directory for debugging pktcdvd.
  debugfs: Modified default dir of debugfs for debugging UHCI.
  debugfs: Change debugfs directory of IWMC3200
  debugfs: Change debuhgfs directory of trace-events-sample.h
  debugfs: Fix mount directory of debugfs by default in events.txt
  hpilo: add poll f_op
  hpilo: add interrupt handler
  hpilo: staging for interrupt handling
  driver core: platform_device_add_data(): use kmemdup()
  Driver core: Add support for compatibility classes
  uio: add generic driver for PCI 2.3 devices
  driver-core: move dma-coherent.c from kernel to driver/base
  mem_class: fix bug
  mem_class: use minor as index instead of searching the array
  driver model: constify attribute groups
  UIO: remove 'default n' from Kconfig
  Driver core: Add accessor for device platform data
  Driver core: move dev_get/set_drvdata to drivers/base/dd.c
  Driver core: add new device to bus's list before probing
2009-09-16 08:27:10 -07:00
Kay Sievers 2b2af54a5b Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.

Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.

If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.

If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.

It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Tested-By: Harald Hoyer <harald@redhat.com>
Tested-By: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:49 -07:00
Linus Torvalds ada3fa1505 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
  powerpc64: convert to dynamic percpu allocator
  sparc64: use embedding percpu first chunk allocator
  percpu: kill lpage first chunk allocator
  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
  percpu: update embedding first chunk allocator to handle sparse units
  percpu: use group information to allocate vmap areas sparsely
  vmalloc: implement pcpu_get_vm_areas()
  vmalloc: separate out insert_vmalloc_vm()
  percpu: add chunk->base_addr
  percpu: add pcpu_unit_offsets[]
  percpu: introduce pcpu_alloc_info and pcpu_group_info
  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
  percpu: add @align to pcpu_fc_alloc_fn_t
  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
  percpu: drop @static_size from first chunk allocators
  percpu: generalize first chunk allocator selection
  percpu: build first chunk allocators selectively
  percpu: rename 4k first chunk allocator to page
  percpu: improve boot messages
  percpu: fix pcpu_reclaim() locking
  ...

Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-15 09:39:44 -07:00
Linus Torvalds 774a694f8c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (64 commits)
  sched: Fix sched::sched_stat_wait tracepoint field
  sched: Disable NEW_FAIR_SLEEPERS for now
  sched: Keep kthreads at default priority
  sched: Re-tune the scheduler latency defaults to decrease worst-case latencies
  sched: Turn off child_runs_first
  sched: Ensure that a child can't gain time over it's parent after fork()
  sched: enable SD_WAKE_IDLE
  sched: Deal with low-load in wake_affine()
  sched: Remove short cut from select_task_rq_fair()
  sched: Turn on SD_BALANCE_NEWIDLE
  sched: Clean up topology.h
  sched: Fix dynamic power-balancing crash
  sched: Remove reciprocal for cpu_power
  sched: Try to deal with low capacity, fix update_sd_power_savings_stats()
  sched: Try to deal with low capacity
  sched: Scale down cpu_power due to RT tasks
  sched: Implement dynamic cpu_power
  sched: Add smt_gain
  sched: Update the cpu_power sum during load-balance
  sched: Add SD_PREFER_SIBLING
  ...
2009-09-11 13:23:18 -07:00
Paul E. McKenney 7db905e636 rcu: Move end of special early-boot RCU operation earlier
Ingo was getting warnings from rcu_scheduler_starting()
indicating that context switches had occurred before RCU ended
its special early-boot handling of grace periods.

This is a dangerous condition, as it indicates that RCU might
have prematurely ended grace periods.  This exploratory fix
moves rcu_scheduler_starting() earlier in boot.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-04 09:29:34 +02:00
Thomas Gleixner fa84e9eecf init: Move sched_clock_init after late_time_init
Some architectures initialize clocks and timers in late_time_init and
x86 wants to do the same to avoid FIXMAP hackery for calibrating the
TSC. That would result in undefined sched_clock readout and wreckaged
printk timestamps again. We probably have those already on archs which
do all their time/clock setup in late_time_init.

There is no harm to move that after late_time_init except that a few
more boot timestamps are stale. The scheduler is not active at that
point so no real wreckage is expected.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Cc: linux-arch@vger.kernel.org
2009-08-27 16:38:18 +02:00
Linus Torvalds 7d63e6359a Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: Fix too large stack usage in do_one_initcall()
  tracing: handle broken names in ftrace filter
  ftrace: Unify effect of writing to trace_options and option/*
2009-08-25 11:23:43 -07:00
Ingo Molnar 4a683bf94b tracing: Fix too large stack usage in do_one_initcall()
One of my testboxes triggered this nasty stack overflow crash
during SCSI probing:

[    5.874004] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    5.875004] device: 'sda': device_add
[    5.878004] BUG: unable to handle kernel NULL pointer dereference at 00000a0c
[    5.878004] IP: [<b1008321>] print_context_stack+0x81/0x110
[    5.878004] *pde = 00000000
[    5.878004] Thread overran stack, or stack corrupted
[    5.878004] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[    5.878004] last sysfs file:
[    5.878004]
[    5.878004] Pid: 1, comm: swapper Not tainted (2.6.31-rc6-tip-01272-g9919e28-dirty #5685)
[    5.878004] EIP: 0060:[<b1008321>] EFLAGS: 00010083 CPU: 0
[    5.878004] EIP is at print_context_stack+0x81/0x110
[    5.878004] EAX: cf8a3000 EBX: cf8a3fe4 ECX: 00000049 EDX: 00000000
[    5.878004] ESI: b1cfce84 EDI: 00000000 EBP: cf8a3018 ESP: cf8a2ff4
[    5.878004]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[    5.878004] Process swapper (pid: 1, ti=cf8a2000 task=cf8a8000 task.ti=cf8a3000)
[    5.878004] Stack:
[    5.878004]  b1004867 fffff000 cf8a3ffc
[    5.878004] Call Trace:
[    5.878004]  [<b1004867>] ? kernel_thread_helper+0x7/0x10
[    5.878004] BUG: unable to handle kernel NULL pointer dereference at 00000a0c
[    5.878004] IP: [<b1008321>] print_context_stack+0x81/0x110
[    5.878004] *pde = 00000000
[    5.878004] Thread overran stack, or stack corrupted
[    5.878004] Oops: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC

The oops did not reveal any more details about the real stack
that we have and the system got into an infinite loop of
recursive pagefaults.

So i booted with CONFIG_STACK_TRACER=y and the 'stacktrace' boot
parameter. The box did not crash (timings/conditions probably
changed a tiny bit to trigger the catastrophic crash), but the
/debug/tracing/stack_trace file was rather revealing:

        Depth    Size   Location    (72 entries)
        -----    ----   --------
  0)     3704      52   __change_page_attr+0xb8/0x290
  1)     3652      24   __change_page_attr_set_clr+0x43/0x90
  2)     3628      60   kernel_map_pages+0x108/0x120
  3)     3568      40   prep_new_page+0x7d/0x130
  4)     3528      84   get_page_from_freelist+0x106/0x420
  5)     3444     116   __alloc_pages_nodemask+0xd7/0x550
  6)     3328      36   allocate_slab+0xb1/0x100
  7)     3292      36   new_slab+0x1c/0x160
  8)     3256      36   __slab_alloc+0x133/0x2b0
  9)     3220       4   kmem_cache_alloc+0x1bb/0x1d0
 10)     3216     108   create_object+0x28/0x250
 11)     3108      40   kmemleak_alloc+0x81/0xc0
 12)     3068      24   kmem_cache_alloc+0x162/0x1d0
 13)     3044      52   scsi_pool_alloc_command+0x29/0x70
 14)     2992      20   scsi_host_alloc_command+0x22/0x70
 15)     2972      24   __scsi_get_command+0x1b/0x90
 16)     2948      28   scsi_get_command+0x35/0x90
 17)     2920      24   scsi_setup_blk_pc_cmnd+0xd4/0x100
 18)     2896     128   sd_prep_fn+0x332/0xa70
 19)     2768      36   blk_peek_request+0xe7/0x1d0
 20)     2732      56   scsi_request_fn+0x54/0x520
 21)     2676      12   __generic_unplug_device+0x2b/0x40
 22)     2664      24   blk_execute_rq_nowait+0x59/0x80
 23)     2640     172   blk_execute_rq+0x6b/0xb0
 24)     2468      32   scsi_execute+0xe0/0x140
 25)     2436      64   scsi_execute_req+0x152/0x160
 26)     2372      60   scsi_vpd_inquiry+0x6c/0x90
 27)     2312      44   scsi_get_vpd_page+0x112/0x160
 28)     2268      52   sd_revalidate_disk+0x1df/0x320
 29)     2216      92   rescan_partitions+0x98/0x330
 30)     2124      52   __blkdev_get+0x309/0x350
 31)     2072       8   blkdev_get+0xf/0x20
 32)     2064      44   register_disk+0xff/0x120
 33)     2020      36   add_disk+0x6e/0xb0
 34)     1984      44   sd_probe_async+0xfb/0x1d0
 35)     1940      44   __async_schedule+0xf4/0x1b0
 36)     1896       8   async_schedule+0x12/0x20
 37)     1888      60   sd_probe+0x305/0x360
 38)     1828      44   really_probe+0x63/0x170
 39)     1784      36   driver_probe_device+0x5d/0x60
 40)     1748      16   __device_attach+0x49/0x50
 41)     1732      32   bus_for_each_drv+0x5b/0x80
 42)     1700      24   device_attach+0x6b/0x70
 43)     1676      16   bus_attach_device+0x47/0x60
 44)     1660      76   device_add+0x33d/0x400
 45)     1584      52   scsi_sysfs_add_sdev+0x6a/0x2c0
 46)     1532     108   scsi_add_lun+0x44b/0x460
 47)     1424     116   scsi_probe_and_add_lun+0x182/0x4e0
 48)     1308      36   __scsi_add_device+0xd9/0xe0
 49)     1272      44   ata_scsi_scan_host+0x10b/0x190
 50)     1228      24   async_port_probe+0x96/0xd0
 51)     1204      44   __async_schedule+0xf4/0x1b0
 52)     1160       8   async_schedule+0x12/0x20
 53)     1152      48   ata_host_register+0x171/0x1d0
 54)     1104      60   ata_pci_sff_activate_host+0xf3/0x230
 55)     1044      44   ata_pci_sff_init_one+0xea/0x100
 56)     1000      48   amd_init_one+0xb2/0x190
 57)      952       8   local_pci_probe+0x13/0x20
 58)      944      32   pci_device_probe+0x68/0x90
 59)      912      44   really_probe+0x63/0x170
 60)      868      36   driver_probe_device+0x5d/0x60
 61)      832      20   __driver_attach+0x89/0xa0
 62)      812      32   bus_for_each_dev+0x5b/0x80
 63)      780      12   driver_attach+0x1e/0x20
 64)      768      72   bus_add_driver+0x14b/0x2d0
 65)      696      36   driver_register+0x6e/0x150
 66)      660      20   __pci_register_driver+0x53/0xc0
 67)      640       8   amd_init+0x14/0x16
 68)      632     572   do_one_initcall+0x2b/0x1d0
 69)       60      12   do_basic_setup+0x56/0x6a
 70)       48      20   kernel_init+0x84/0xce
 71)       28      28   kernel_thread_helper+0x7/0x10

There's a lot of fat functions on that stack trace, but
the largest of all is do_one_initcall(). This is due to
the boot trace entry variables being on the stack.

Fixing this is relatively easy, initcalls are fundamentally
serialized, so we can move the local variables to file scope.

Note that this large stack footprint was present for a
couple of months already - what pushed my system over
the edge was the addition of kmemleak to the call-chain:

  6)     3328      36   allocate_slab+0xb1/0x100
  7)     3292      36   new_slab+0x1c/0x160
  8)     3256      36   __slab_alloc+0x133/0x2b0
  9)     3220       4   kmem_cache_alloc+0x1bb/0x1d0
 10)     3216     108   create_object+0x28/0x250
 11)     3108      40   kmemleak_alloc+0x81/0xc0
 12)     3068      24   kmem_cache_alloc+0x162/0x1d0
 13)     3044      52   scsi_pool_alloc_command+0x29/0x70

This pushes the total to ~3800 bytes, only a tiny bit
more was needed to corrupt the on-kernel-stack thread_info.

The fix reduces the stack footprint from 572 bytes
to 28 bytes.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-21 13:03:22 +02:00
Tejun Heo 384be2b18a Merge branch 'percpu-for-linus' into percpu-for-next
Conflicts:
	arch/sparc/kernel/smp_64.c
	arch/x86/kernel/cpu/perf_counter.c
	arch/x86/kernel/setup_percpu.c
	drivers/cpufreq/cpufreq_ondemand.c
	mm/percpu.c

Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids.  As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-08-14 14:45:31 +09:00
Tejun Heo d6647bdf98 init: set nr_cpu_ids before setup_per_cpu_areas()
nr_cpu_ids is dependent only on cpu_possible_map and
setup_per_cpu_areas() already depends on cpu_possible_map and will use
nr_cpu_ids.  Initialize nr_cpu_ids before setting up percpu areas.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-08-14 12:56:54 +09:00
Tejun Heo c43768cbb7 Merge branch 'master' into for-next
Pull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix
changes.  As alpha in percpu tree uses 'weak' attribute instead of
inline assembly, there's no need for __used attribute.

Conflicts:
	arch/alpha/include/asm/percpu.h
	arch/mn10300/kernel/vmlinux.lds.S
	include/linux/percpu-defs.h
2009-07-04 07:13:18 +09:00
Tejun Heo e74e396204 percpu: use dynamic percpu allocator as the default percpu allocator
This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use
dynamic percpu allocator.  The first chunk is allocated using
embedding helper and 8k is reserved for modules.  This ensures that
the new allocator behaves almost identically to the original allocator
as long as static percpu variables are concerned, so it shouldn't
introduce much breakage.

s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing
range limit the addressing model imposes.  Unfortunately, this breaks
if the address is specified using a variable, so for now, the two
archs aren't converted.

The following architectures are affected by this change.

* sh
* arm
* cris
* mips
* sparc(32)
* blackfin
* avr32
* parisc (broken, under investigation)
* m32r
* powerpc(32)

As this change makes the dynamic allocator the default one,
CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert -
CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted
archs.  These archs implement their own setup_per_cpu_areas() and the
conversion is not trivial.

* powerpc(64)
* sparc(64)
* ia64
* alpha
* s390

Boot and batch alloc/free tests on x86_32 with debug code (x86_32
doesn't use default first chunk initialization).  Compile tested on
sparc(32), powerpc(32), arm and alpha.

Kyle McMartin reported that this change breaks parisc.  The problem is
still under investigation and he is okay with pushing this patch
forward and fixing parisc later.

[ Impact: use dynamic allocator for most archs w/o custom percpu setup ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
2009-06-24 15:13:35 +09:00
Len Brown fbe8cddd2d Merge branches 'acerhdf', 'acpi-pci-bind', 'bjorn-pci-root', 'bugzilla-12904', 'bugzilla-13121', 'bugzilla-13396', 'bugzilla-13533', 'bugzilla-13612', 'c3_lock', 'hid-cleanups', 'misc-2.6.31', 'pdc-leak-fix', 'pnpacpi', 'power_nocheck', 'thinkpad_acpi', 'video' and 'wmi' into release 2009-06-24 01:19:50 -04:00
Linus Torvalds 31950eb66f mm/init: cpu_hotplug_init() must be initialized before SLAB
SLAB uses get/put_online_cpus() which use a mutex which is itself only
initialized when cpu_hotplug_init() is called.  Currently we hang suring
boot in SLAB due to doing that too late.

Reported by James Bottomley and Sachin Sant (and possibly others).
Debugged by Benjamin Herrenschmidt.

This just removes the dynamic initialization of the data structures, and
replaces it with a static one, avoiding this dependency entirely, and
removing one unnecessary special initcall.

Tested-by: Sachin Sant <sachinp@in.ibm.com>
Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-22 21:18:12 -07:00
Benjamin Herrenschmidt dcce284a25 mm: Extend gfp masking to the page allocator
The page allocator also needs the masking of gfp flags during boot,
so this moves it out of slab/slub and uses it with the page allocator
as well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:12:57 -07:00
Peter Oberparleiter b99b87f70c kernel: constructor support
Call constructors (gcc-generated initcall-like functions) during kernel
start and module load.  Constructors are e.g.  used for gcov data
initialization.

Disable constructor support for usermode Linux to prevent conflicts with
host glibc.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:57 -07:00
Benjamin Herrenschmidt c868d55011 mm: Move pgtable_cache_init() earlier
Some architectures need to initialize SLAB caches to be able
to allocate page tables. They do that from pgtable_cache_init()
so the later should be called earlier now, best is before
vmalloc_init().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 21:14:42 -07:00
Linus Torvalds 517d08699b Merge branch 'akpm'
* akpm: (182 commits)
  fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
  fbdev: *bfin*: fix __dev{init,exit} markings
  fbdev: *bfin*: drop unnecessary calls to memset
  fbdev: bfin-t350mcqb-fb: drop unused local variables
  fbdev: blackfin has __raw I/O accessors, so use them in fb.h
  fbdev: s1d13xxxfb: add accelerated bitblt functions
  tcx: use standard fields for framebuffer physical address and length
  fbdev: add support for handoff from firmware to hw framebuffers
  intelfb: fix a bug when changing video timing
  fbdev: use framebuffer_release() for freeing fb_info structures
  radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
  s3c-fb: CPUFREQ frequency scaling support
  s3c-fb: fix resource releasing on error during probing
  carminefb: fix possible access beyond end of carmine_modedb[]
  acornfb: remove fb_mmap function
  mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
  mb862xxfb: restrict compliation of platform driver to PPC
  Samsung SoC Framebuffer driver: add Alpha Channel support
  atmel-lcdc: fix pixclock upper bound detection
  offb: use framebuffer_alloc() to allocate fb_info struct
  ...

Manually fix up conflicts due to kmemcheck in mm/slab.c
2009-06-16 19:50:13 -07:00
Miao Xie 58568d2a82 cpuset,mm: update tasks' mems_allowed in time
Fix allocating page cache/slab object on the unallowed node when memory
spread is set by updating tasks' mems_allowed after its cpuset's mems is
changed.

In order to update tasks' mems_allowed in time, we must modify the code of
memory policy.  Because the memory policy is applied in the process's
context originally.  After applying this patch, one task directly
manipulates anothers mems_allowed, and we use alloc_lock in the
task_struct to protect mems_allowed and memory policy of the task.

But in the fast path, we didn't use lock to protect them, because adding a
lock may lead to performance regression.  But if we don't add a lock,the
task might see no nodes when changing cpuset's mems_allowed to some
non-overlapping set.  In order to avoid it, we set all new allowed nodes,
then clear newly disallowed ones.

[lee.schermerhorn@hp.com:
  The rework of mpol_new() to extract the adjusting of the node mask to
  apply cpuset and mpol flags "context" breaks set_mempolicy() and mbind()
  with MPOL_PREFERRED and a NULL nodemask--i.e., explicit local
  allocation.  Fix this by adding the check for MPOL_PREFERRED and empty
  node mask to mpol_new_mpolicy().

  Remove the now unneeded 'nodes = NULL' from mpol_new().

  Note that mpol_new_mempolicy() is always called with a non-NULL
  'nodes' parameter now that it has been removed from mpol_new().
  Therefore, we don't need to test nodes for NULL before testing it for
  'empty'.  However, just to be extra paranoid, add a VM_BUG_ON() to
  verify this assumption.]
[lee.schermerhorn@hp.com:

  I don't think the function name 'mpol_new_mempolicy' is descriptive
  enough to differentiate it from mpol_new().

  This function applies cpuset set context, usually constraining nodes
  to those allowed by the cpuset.  However, when the 'RELATIVE_NODES flag
  is set, it also translates the nodes.  So I settled on
  'mpol_set_nodemask()', because the comment block for mpol_new() mentions
  that we need to call this function to "set nodes".

  Some additional minor line length, whitespace and typo cleanup.]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:31 -07:00
Vegard Nossum 722f2a6c87 Merge commit 'linus/master' into HEAD
Conflicts:
	MAINTAINERS

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-15 15:50:49 +02:00
Vegard Nossum dfec072ecd kmemcheck: add the kmemcheck core
General description: kmemcheck is a patch to the linux kernel that
detects use of uninitialized memory. It does this by trapping every
read and write to memory that was allocated dynamically (e.g. using
kmalloc()). If a memory address is read that has not previously been
written to, a message is printed to the kernel log.

Thanks to Andi Kleen for the set_memory_4k() solution.

Andrew Morton suggested documenting the shadow member of struct page.

Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

[export kmemcheck_mark_initialized]
[build fix for setup_max_cpus]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
2009-06-13 15:37:30 +02:00
Len Brown 4a7a16dc06 ACPI: move declaration acpi_early_init() to acpi.h
Signed-off-by: Len Brown <len.brown@intel.com>
2009-06-12 20:50:38 -04:00
Pekka Enberg 7e85ee0c1d slab,slub: don't enable interrupts during early boot
As explained by Benjamin Herrenschmidt:

  Oh and btw, your patch alone doesn't fix powerpc, because it's missing
  a whole bunch of GFP_KERNEL's in the arch code... You would have to
  grep the entire kernel for things that check slab_is_available() and
  even then you'll be missing some.

  For example, slab_is_available() didn't always exist, and so in the
  early days on powerpc, we used a mem_init_done global that is set form
  mem_init() (not perfect but works in practice). And we still have code
  using that to do the test.

Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
in early boot code to avoid enabling interrupts.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-12 18:53:33 +03:00
KAMEZAWA Hiroyuki ca371c0d7e memcg: fix page_cgroup fatal error in FLATMEM
Now, SLAB is configured in very early stage and it can be used in
init routine now.

But replacing alloc_bootmem() in FLAT/DISCONTIGMEM's page_cgroup()
initialization breaks the allocation, now.
(Works well in SPARSEMEM case...it supports MEMORY_HOTPLUG and
 size of page_cgroup is in reasonable size (< 1 << MAX_ORDER.)

This patch revive FLATMEM+memory cgroup by using alloc_bootmem.

In future,
We stop to support FLATMEM (if no users) or rewrite codes for flatmem
completely.But this will adds more messy codes and overheads.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-12 11:00:54 +03:00
Linus Torvalds 512626a04e Merge branch 'for-linus' of git://linux-arm.org/linux-2.6
* 'for-linus' of git://linux-arm.org/linux-2.6:
  kmemleak: Add the corresponding MAINTAINERS entry
  kmemleak: Simple testing module for kmemleak
  kmemleak: Enable the building of the memory leak detector
  kmemleak: Remove some of the kmemleak false positives
  kmemleak: Add modules support
  kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash
  kmemleak: Add the vmalloc memory allocation/freeing hooks
  kmemleak: Add the slub memory allocation/freeing hooks
  kmemleak: Add the slob memory allocation/freeing hooks
  kmemleak: Add the slab memory allocation/freeing hooks
  kmemleak: Add documentation on the memory leak detector
  kmemleak: Add the base support

Manual conflict resolution (with the slab/earlyboot changes) in:
	drivers/char/vt.c
	init/main.c
	mm/slab.c
2009-06-11 14:15:57 -07:00
Pekka Enberg 444f478f65 init: introduce mm_init()
As suggested by Christoph Lameter, introduce mm_init() now that we initialize
all the kernel memory allocations together.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-11 19:27:03 +03:00
Pekka Enberg 43ebdac42f vmalloc: use kzalloc() instead of alloc_bootmem()
We can call vmalloc_init() after kmem_cache_init() and use kzalloc() instead of
the bootmem allocator when initializing vmalloc data structures.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-11 19:17:05 +03:00
Pekka Enberg 83b519e8b9 slab: setup allocators earlier in the boot sequence
This patch makes kmalloc() available earlier in the boot sequence so we can get
rid of some bootmem allocations. The bulk of the changes are due to
kmem_cache_init() being called with interrupts disabled which requires some
changes to allocator boostrap code.

Note: 32-bit x86 does WP protect test in mem_init() so we must setup traps
before we call mem_init() during boot as reported by Ingo Molnar:

  We have a hard crash in the WP-protect code:

  [    0.000000] Checking if this processor honours the WP bit even in supervisor mode...BUG: Int 14: CR2 ffcff000
  [    0.000000]      EDI 00000188  ESI 00000ac7  EBP c17eaf9c  ESP c17eaf8c
  [    0.000000]      EBX 000014e0  EDX 0000000e  ECX 01856067  EAX 00000001
  [    0.000000]      err 00000003  EIP c10135b1   CS 00000060  flg 00010002
  [    0.000000] Stack: c17eafa8 c17fd410 c16747bc c17eafc4 c17fd7e5 000011fd f8616000 c18237cc
  [    0.000000]        00099800 c17bb000 c17eafec c17f1668 000001c5 c17f1322 c166e039 c1822bf0
  [    0.000000]        c166e033 c153a014 c18237cc 00020800 c17eaff8 c17f106a 00020800 01ba5003
  [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30-tip-02161-g7a74539-dirty #52203
  [    0.000000] Call Trace:
  [    0.000000]  [<c15357c2>] ? printk+0x14/0x16
  [    0.000000]  [<c10135b1>] ? do_test_wp_bit+0x19/0x23
  [    0.000000]  [<c17fd410>] ? test_wp_bit+0x26/0x64
  [    0.000000]  [<c17fd7e5>] ? mem_init+0x1ba/0x1d8
  [    0.000000]  [<c17f1668>] ? start_kernel+0x164/0x2f7
  [    0.000000]  [<c17f1322>] ? unknown_bootoption+0x0/0x19c
  [    0.000000]  [<c17f106a>] ? __init_begin+0x6a/0x6f

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-11 19:15:56 +03:00
Catalin Marinas 3c7b4e6b8b kmemleak: Add the base support
This patch adds the base support for the kernel memory leak
detector. It traces the memory allocation/freeing in a way similar to
the Boehm's conservative garbage collector, the difference being that
the unreferenced objects are not freed but only shown in
/sys/kernel/debug/kmemleak. Enabling this feature introduces an
overhead to memory allocations.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2009-06-11 17:03:28 +01:00
Linus Torvalds 8623661180 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits)
  Revert "x86, bts: reenable ptrace branch trace support"
  tracing: do not translate event helper macros in print format
  ftrace/documentation: fix typo in function grapher name
  tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK
  tracing: add protection around module events unload
  tracing: add trace_seq_vprint interface
  tracing: fix the block trace points print size
  tracing/events: convert block trace points to TRACE_EVENT()
  ring-buffer: fix ret in rb_add_time_stamp
  ring-buffer: pass in lockdep class key for reader_lock
  tracing: add annotation to what type of stack trace is recorded
  tracing: fix multiple use of __print_flags and __print_symbolic
  tracing/events: fix output format of user stack
  tracing/events: fix output format of kernel stack
  tracing/trace_stack: fix the number of entries in the header
  ring-buffer: discard timestamps that are at the start of the buffer
  ring-buffer: try to discard unneeded timestamps
  ring-buffer: fix bug in ring_buffer_discard_commit
  ftrace: do not profile functions when disabled
  tracing: make trace pipe recognize latency format flag
  ...
2009-06-10 19:53:40 -07:00
Alex Riesen 657cafa6b0 Use a format for linux_banner
There is no format specifiers left in the linux_banner, and gcc-4.3
complains seeing the printk.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-24 11:19:11 -07:00
Ingo Molnar 44347d947f Merge branch 'linus' into tracing/core
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
              on a handful of tracing fixes present in .30-rc5-almost.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-07 11:17:34 +02:00
Magnus Damm 13977091a9 Driver Core: early platform driver
V3 of the early platform driver implementation.

Platform drivers are great for embedded platforms because we can separate
driver configuration from the actual driver.  So base addresses,
interrupts and other configuration can be kept with the processor or board
code, and the platform driver can be reused by many different platforms.

For early devices we have nothing today.  For instance, to configure early
timers and early serial ports we cannot use platform devices.  This
because the setup order during boot.  Timers are needed before the
platform driver core code is available.  The same goes for early printk
support.  Early in this case means before initcalls.

These early drivers today have their configuration either hard coded or
they receive it using some special configuration method.  This is working
quite well, but if we want to support both regular kernel modules and
early devices then we need to have two ways of configuring the same
driver.  A single way would be better.

The early platform driver patch is basically a set of functions that allow
drivers to register themselves and architecture code to locate them and
probe.  Registration happens through early_param().  The time for the
probe is decided by the architecture code.

See Documentation/driver-model/platform.txt for more details.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-16 16:17:10 -07:00
Zhaolei 02af61bb50 tracing, kmemtrace: Separate include/trace/kmemtrace.h to kmemtrace part and tracepoint part
Impact: refactor code for future changes

Current kmemtrace.h is used both as header file of kmemtrace and kmem's
tracepoints definition.

Tracepoints' definition file may be used by other code, and should only have
definition of tracepoint.

We can separate include/trace/kmemtrace.h into 2 files:

  include/linux/kmemtrace.h: header file for kmemtrace
  include/trace/kmem.h:      definition of kmem tracepoints

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DEE68A.5040902@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-12 15:22:55 +02:00
Ingo Molnar 8302294f43 Merge branch 'tracing/core-v2' into tracing-for-linus
Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c
2009-04-02 00:49:02 +02:00
Hannes Eder acdd052a28 init/main.c: fix sparse warnings: context imbalance
Impact: Attribute function 'init_post' with __releases(...).

Fix these sparse warnings:
  init/main.c:805:21: warning: context imbalance in 'init_post' - unexpected unlock
  init/main.c:899:9: warning: context imbalance in 'kernel_init' - wrong count at exit

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:18 -07:00
Rusty Russell 2b17fa506c cpumask: use set_cpu_active in init/main.c
cpu_active_map is deprecated in favor of cpu_active_mask, which is
const for safety: we use accessors now (set_cpu_active) is we really
want to make a change.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30 22:05:12 +10:30
Rusty Russell 1a2142afa5 cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL
Impact: cleanup

(Thanks to Al Viro for reminding me of this, via Ingo)

CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:

	#define CPU_MASK_ALL (cpumask_t) { { ... } }

Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:

	#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)

Which formalizes this practice.  One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).

So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
with the modern "cpu_all_mask" (a real const struct cpumask *).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mike Travis <travis@sgi.com>
2009-03-30 22:05:11 +10:30
Ingo Molnar 6e15cf0486 Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2
Conflicts:
	arch/parisc/kernel/irq.c
	arch/x86/include/asm/fixmap_64.h
	arch/x86/include/asm/setup.h
	kernel/irq/handle.c

Semantic merge:
        arch/x86/include/asm/fixmap.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-27 17:28:43 +01:00
Lai Jiangshan 759ee0915d init,cpuset: fix initialize order
Impact: cpuset_wq should be initialized after init_workqueues()

When I read /debugfs/tracing/trace_stat/workqueues,
I got this:

 # CPU  INSERTED  EXECUTED   NAME
 # |      |         |          |

   0      0          0       cpuset
   0    285        285       events/0
   0      2          2       work_on_cpu/0
   0   1115       1115       khelper
   0    325        325       kblockd/0
   0      0          0       kacpid
   0      0          0       kacpi_notify
   0      0          0       ata/0
   0      0          0       ata_aux
   0      0          0       ksuspend_usbd
   0      0          0       aio/0
   0      0          0       nfsiod
   0      0          0       kpsmoused
   0      0          0       kstriped
   0      0          0       kondemand/0
   0      1          1       hid_compat
   0      0          0       rpciod/0

   1     64         64       events/1
   1      2          2       work_on_cpu/1
   1      5          5       kblockd/1
   1      0          0       ata/1
   1      0          0       aio/1
   1      0          0       kondemand/1
   1      0          0       rpciod/1

I found "cpuset" is at the earliest.

I found a create_singlethread_workqueue() is earlier than
init_workqueues():

kernel_init()
->cpuset_init_smp()
  ->create_singlethread_workqueue()
->do_basic_setup()
  ->init_workqueues()

I think it's better that create_singlethread_workqueue() is called
after workqueue subsystem has been initialized.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Menage <menage@google.com>
Cc: miaoxie <miaox@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <49C9F416.1050707@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-25 18:32:35 +01:00
Ingo Molnar f0ef039851 Merge branch 'x86/core' into tracing/textedit
Conflicts:
	arch/x86/Kconfig
	block/blktrace.c
	kernel/irq/handle.c

Semantic conflict:
	kernel/trace/blktrace.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 16:45:01 +01:00
Ingo Molnar a1413c89ae Merge branch 'x86/urgent' into x86/core
Conflicts:
	arch/x86/include/asm/fixmap_64.h
Semantic merge:
	arch/x86/include/asm/fixmap.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-05 21:48:50 +01:00
Ingo Molnar a1be621dfa Merge branch 'tracing/ftrace'; commit 'v2.6.29-rc7' into tracing/core 2009-03-04 11:14:47 +01:00
Paul E. McKenney a682604838 rcu: Teach RCU that idle task is not quiscent state at boot
This patch fixes a bug located by Vegard Nossum with the aid of
kmemcheck, updated based on review comments from Nick Piggin,
Ingo Molnar, and Andrew Morton.  And cleans up the variable-name
and function-name language.  ;-)

The boot CPU runs in the context of its idle thread during boot-up.
During this time, idle_cpu(0) will always return nonzero, which will
fool Classic and Hierarchical RCU into deciding that a large chunk of
the boot-up sequence is a big long quiescent state.  This in turn causes
RCU to prematurely end grace periods during this time.

This patch changes the rcutree.c and rcuclassic.c rcu_check_callbacks()
function to ignore the idle task as a quiescent state until the
system has started up the scheduler in rest_init(), introducing a
new non-API function rcu_idle_now_means_idle() to inform RCU of this
transition.  RCU maintains an internal rcu_idle_cpu_truthful variable
to track this state, which is then used by rcu_check_callback() to
determine if it should believe idle_cpu().

Because this patch has the effect of disallowing RCU grace periods
during long stretches of the boot-up sequence, this patch also introduces
Josh Triplett's UP-only optimization that makes synchronize_rcu() be a
no-op if num_online_cpus() returns 1.  This allows boot-time code that
calls synchronize_rcu() to proceed normally.  Note, however, that RCU
callbacks registered by call_rcu() will likely queue up until later in
the boot sequence.  Although rcuclassic and rcutree can also use this
same optimization after boot completes, rcupreempt must restrict its
use of this optimization to the portion of the boot sequence before the
scheduler starts up, given that an rcupreempt RCU read-side critical
section may be preeempted.

In addition, this patch takes Nick Piggin's suggestion to make the
system_state global variable be __read_mostly.

Changes since v4:

o	Changes the name of the introduced function and variable to
	be less emotional.  ;-)

Changes since v3:

o	WARN_ON(nr_context_switches() > 0) to verify that RCU
	switches out of boot-time mode before the first context
	switch, as suggested by Nick Piggin.

Changes since v2:

o	Created rcu_blocking_is_gp() internal-to-RCU API that
	determines whether a call to synchronize_rcu() is itself
	a grace period.

o	The definition of rcu_blocking_is_gp() for rcuclassic and
	rcutree checks to see if but a single CPU is online.

o	The definition of rcu_blocking_is_gp() for rcupreempt
	checks to see both if but a single CPU is online and if
	the system is still in early boot.

	This allows rcupreempt to again work correctly if running
	on a single CPU after booting is complete.

o	Added check to rcupreempt's synchronize_sched() for there
	being but one online CPU.

Tested all three variants both SMP and !SMP, booted fine, passed a short
rcutorture test on both x86 and Power.

Located-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26 04:08:14 +01:00
Ingo Molnar 65a4e574d2 smp, generic: introduce arch_disable_smp_support() instead of disable_ioapic_setup()
Impact: cleanup

disable_ioapic_setup() in init/main.c is ugly as the function is
x86-specific. The #ifdef inline prototype there is ugly too.

Replace it with a generic arch_disable_smp_support() function - which
has a weak alias for non-x86 architectures and for non-ioapic x86 builds.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05 22:27:54 +01:00
Ingo Molnar b2b062b816 Merge branch 'core/percpu' into stackprotector
Conflicts:
	arch/x86/include/asm/pda.h
	arch/x86/include/asm/system.h

Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 18:37:14 +01:00
Ingo Molnar 99cd707489 Merge commit 'v2.6.29-rc1' into tracing/urgent 2009-01-11 03:43:52 +01:00
Linus Torvalds 67acd8b4b7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async
* git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async:
  async: don't do the initcall stuff post boot
  bootchart: improve output based on Dave Jones' feedback
  async: make the final inode deletion an asynchronous event
  fastboot: Make libata initialization even more async
  fastboot: make the libata port scan asynchronous
  fastboot: make scsi probes asynchronous
  async: Asynchronous function calls to speed up kernel boot
2009-01-07 15:35:47 -08:00
Linus Torvalds 57c44c5f6f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
  trivial: chack -> check typo fix in main Makefile
  trivial: Add a space (and a comma) to a printk in 8250 driver
  trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx
  trivial: Fix misspelling of "firmware" in powerpc Makefile
  trivial: Fix misspelling of "firmware" in usb.c
  trivial: Fix misspelling of "firmware" in qla1280.c
  trivial: Fix misspelling of "firmware" in a100u2w.c
  trivial: Fix misspelling of "firmware" in megaraid.c
  trivial: Fix misspelling of "firmware" in ql4_mbx.c
  trivial: Fix misspelling of "firmware" in acpi_memhotplug.c
  trivial: Fix misspelling of "firmware" in ipw2100.c
  trivial: Fix misspelling of "firmware" in atmel.c
  trivial: Fix misspelled firmware in Kconfig
  trivial: fix an -> a typos in documentation and comments
  trivial: fix then -> than typos in comments and documentation
  trivial: update Jesper Juhl CREDITS entry with new email
  trivial: fix singal -> signal typo
  trivial: Fix incorrect use of "loose" in event.c
  trivial: printk: fix indentation of new_text_line declaration
  trivial: rtc-stk17ta8: fix sparse warning
  ...
2009-01-07 11:31:52 -08:00