1
Commit Graph

5264 Commits

Author SHA1 Message Date
Ingo Molnar
8b07cd4451 sparseirq: do not printk when migrating IRQ descriptors
Impact: reduce printk noise

There were a couple of leftover KERN_DEBUG debugging printks, remove
them. Also clarify an error message.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-27 09:29:21 +01:00
Yinghai Lu
00c2363487 sparseirq: remove duplicated arch_early_irq_init()
Impact: clean up

We already have a weak copy of this function in init/main.c

Signed-off-by: Yinghai <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-26 10:43:30 +01:00
KOSAKI Motohiro
18eefedfe8 irq: simplify for_each_irq_desc() usage
Impact: cleanup

all for_each_irq_desc() usage point have !desc check.
then its check can move into for_each_irq_desc() macro.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-26 09:48:18 +01:00
KOSAKI Motohiro
26ddd8d5ca proc: remove ifdef CONFIG_SPARSE_IRQ from stat.c
Impact: cleanup

irq_desc can be NULL when CONFIG_SPARSE_IRQ=y only.
therefore, NULL checking can move into kstat_irqs_cpu() of SPARSE_IRQ version.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: "Yinghai Lu" <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-26 09:48:18 +01:00
KOSAKI Motohiro
f9af0e7091 irq: for_each_irq_desc() move to irqnr.h
Impact: cleanup

before CONFIG_SPARSE_IRQ age, for_each_irq_desc() sat in irqnr.h and
could be called from generic code.

CONFIG_SPARSE_IRQ breaks this assumption, but SPARSE_IRQ version
for_each_irq_desc() also can move into irqnr.h easily.

Also, this patch unifies CONFIG_SPARSE_IRQ and !CONFIG_SPARSE_IRQ
for_each_irq_desc().

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-26 09:48:17 +01:00
KOSAKI Motohiro
51bc39f4ba hrtimer: remove #include <linux/irq.h>
Impact: cleanup

<linux/irq.h> can be removed and should be, because:

  - hrtimer doesn't use any irq feature.
  - <linux/irq.h> shouldn't be include from generic code.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-26 09:48:16 +01:00
Ingo Molnar
860cf8894b Merge branches 'irq/sparseirq', 'irq/genirq' and 'irq/urgent'; commit 'v2.6.28' into irq/core 2008-12-25 16:27:54 +01:00
Li Zefan
20ca9b3f4c cgroups: avoid accessing uninitialized data in failure path
If cgroup_get_rootdir() failed, free_cg_links() will be called in the
failure path, but tmp_cg_links hasn't been initialized at that time.

I introduced this bug in the 2.6.27 merge window.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-23 15:58:21 -08:00
Sharyathi Nagesh
e368d3a836 cgroups: suppress bogus warning messages
Remove spurious warning messages that are thrown onto the console during
cgroup operations.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Sharyathi Nagesh <sharyathi@in.ibm.com>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-23 15:58:21 -08:00
Thomas Gleixner
3d44cc3e01 Null pointer deref with hrtimer_try_to_cancel()
Impact: Prevent kernel crash with posix timer clockid CLOCK_MONOTONIC_RAW

commit 2d42244ae7 (clocksource:
introduce CLOCK_MONOTONIC_RAW) introduced a new clockid, which is only
available to read out the raw not NTP adjusted system time.

The above commit did not prevent that a posix timer can be created
with that clockid. The timer_create() syscall succeeds and initializes
the timer to a non existing hrtimer base. When the timer is deleted
either by timer_delete() or by the exit() cleanup the kernel crashes.

Prevent the creation of timers for CLOCK_MONOTONIC_RAW by setting the
posix clock function to no_timer_create which returns an error code.

Reported-and-tested-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-20 14:13:45 -08:00
Yinghai Lu
b909895739 sparseirq: fix numa_migrate_irq_desc dependency and comments
Impact: reduce kconfig variable scope and clean up

Bartlomiej pointed out that the config dependencies and comments are not right.

update it depend to NUMA, and fix some comments

Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 22:56:02 +01:00
KOSAKI Motohiro
74c8a61304 locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP
Impact: simplify code

commit "08678b0: generic: sparse irqs: use irq_desc() [...]" introduced
the irq_desc_lock_class variable.

But it is used only if CONFIG_SPARSE_IRQ=Y or CONFIG_TRACE_IRQFLAGS=Y.
Otherwise, following warnings happen:

	CC      kernel/irq/handle.o
	kernel/irq/handle.c:26: warning: 'irq_desc_lock_class' defined but not used

Actually, current early_init_irq_lock_class has a bit strange and messy ifdef.
In addition, it is not valueable.

1. this function is protected by !CONFIG_SPARSE_IRQ, but that is not necessary.
   if CONFIG_SPARSE_IRQ=Y, desc of all irq number are initialized by NULL
   at first - then this function calling is safe.

2. this function protected by CONFIG_TRACE_IRQFLAGS too. but it is not
   necessary either, because lockdep_set_class() doesn't have bad side
   effect even if CONFIG_TRACE_IRQFLAGS=n.

This patch bloat kernel size a bit on CONFIG_TRACE_IRQFLAGS=n and
CONFIG_SPARSE_IRQ=Y - but that's ok. early_init_irq_lock_class() is not
a fastpatch at all.

To avoid messy ifdefs is more important than a few bytes diet.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 14:35:53 +01:00
Yinghai Lu
48a1b10aff x86, sparseirq: move irq_desc according to smp_affinity, v7
Impact: improve NUMA handling by migrating irq_desc on smp_affinity changes

if CONFIG_NUMA_MIGRATE_IRQ_DESC is set:

-  make irq_desc to go with affinity aka irq_desc moving etc
-  call move_irq_desc in irq_complete_move()
-  legacy irq_desc is not moved, because they are allocated via static array

for logical apic mode, need to add move_desc_in_progress_in_same_domain,
otherwise it will not be moved ==> also could need two phases to get
irq_desc moved.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-17 00:14:01 +01:00
Paul Menage
307257cf47 cgroups: fix a race between rmdir and remount
When a cgroup is removed, it's unlinked from its parent's children list,
but not actually freed until the last dentry on it is released (at which
point cgrp->root->number_of_cgroups is decremented).

Currently rebind_subsystems checks for the top cgroup's child list being
empty in order to rebind subsystems into or out of a hierarchy - this can
result in the set of subsystems bound to a hierarchy being
removed-but-not-freed cgroup.

The simplest fix for this is to forbid remounts that change the set of
subsystems on a hierarchy that has removed-but-not-freed cgroups.  This
bug can be reproduced via:

mkdir /mnt/cg
mount -t cgroup -o ns,freezer cgroup /mnt/cg
mkdir /mnt/cg/foo
sleep 1h < /mnt/cg/foo &
rmdir /mnt/cg/foo
mount -t cgroup -o remount,ns,devices,freezer cgroup /mnt/cg
kill $!

Though the above will cause oops in -mm only but not mainline, but the bug
can cause memory leak in mainline (and even oops)

Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-15 16:27:07 -08:00
Linus Torvalds
ca7e716c78 Revert "sched_clock: prevent scd->clock from moving backwards"
This reverts commit 5b7dba4ff8, which
caused a regression in hibernate, reported by and bisected by Fabio
Comolli.

This revert fixes

 http://bugzilla.kernel.org/show_bug.cgi?id=12155
 http://bugzilla.kernel.org/show_bug.cgi?id=12149

Bisected-by: Fabio Comolli <fabio.comolli@gmail.com>
Requested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-14 16:23:17 -08:00
Linus Torvalds
f9fc05e762 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: CPU remove deadlock fix
2008-12-10 14:41:06 -08:00
Hugh Dickins
b88ed20594 fix mapping_writably_mapped()
Lee Schermerhorn noticed yesterday that I broke the mapping_writably_mapped
test in 2.6.7!  Bad bad bug, good good find.

The i_mmap_writable count must be incremented for VM_SHARED (just as
i_writecount is for VM_DENYWRITE, but while holding the i_mmap_lock)
when dup_mmap() copies the vma for fork: it has its own more optimal
version of __vma_link_file(), and I missed this out.  So the count
was later going down to 0 (dangerous) when one end unmapped, then
wrapping negative (inefficient) when the other end unmapped.

The only impact on x86 would have been that setting a mandatory lock on
a file which has at some time been opened O_RDWR and mapped MAP_SHARED
(but not necessarily PROT_WRITE) across a fork, might fail with -EAGAIN
when it should succeed, or succeed when it should fail.

But those architectures which rely on flush_dcache_page() to flush
userspace modifications back into the page before the kernel reads it,
may in some cases have skipped the flush after such a fork - though any
repetitive test will soon wrap the count negative, in which case it will
flush_dcache_page() unnecessarily.

Fix would be a two-liner, but mapping variable added, and comment moved.

Reported-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 14:40:45 -08:00
Hugh Dickins
9c24624727 KSYM_SYMBOL_LEN fixes
Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked
to my 966c8c12dc sprint_symbol(): use
less stack exposing a bug in slub's list_locations() -
kallsyms_lookup() writes a 0 to namebuf[KSYM_NAME_LEN-1], but that was
beyond the end of page provided.

The 100 slop which list_locations() allows at end of page looks roughly
enough for all the other stuff it might print after the symbol before
it checks again: break out KSYM_SYMBOL_LEN earlier than before.

Latencytop and ftrace and are using KSYM_NAME_LEN buffers where they
need KSYM_SYMBOL_LEN buffers, and vmallocinfo a 2*KSYM_NAME_LEN buffer
where it wants a KSYM_SYMBOL_LEN buffer: fix those before anyone copies
them.

[akpm@linux-foundation.org: ftrace.h needs module.h]
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc Miles Lane <miles.lane@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 08:01:54 -08:00
Tom Zanussi
fbb5b7ae4b relayfs: fix infinite loop with splice()
Running kmemtraced, which uses splice() on relayfs, causes a hard lock on
x86-64 SMP.  As described by Tom Zanussi:

  It looks like you hit the same problem as described here:

  commit 8191ecd1d1

      splice: fix infinite loop in generic_file_splice_read()

  relay uses the same loop but it never got noticed or fixed.

Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Tested-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 08:01:52 -08:00
Brian King
9a2bd244e1 sched: CPU remove deadlock fix
Impact: fix possible deadlock in CPU hot-remove path

This patch fixes a possible deadlock scenario in the CPU remove path.
migration_call grabs rq->lock, then wakes up everything on rq->migration_queue
with the lock held. Then one of the tasks on the migration queue ends up
calling tg_shares_up which then also tries to acquire the same rq->lock.

[c000000058eab2e0] c000000000502078 ._spin_lock_irqsave+0x98/0xf0
[c000000058eab370] c00000000008011c .tg_shares_up+0x10c/0x20c
[c000000058eab430] c00000000007867c .walk_tg_tree+0xc4/0xfc
[c000000058eab4d0] c0000000000840c8 .try_to_wake_up+0xb0/0x3c4
[c000000058eab590] c0000000000799a0 .__wake_up_common+0x6c/0xe0
[c000000058eab640] c00000000007ada4 .complete+0x54/0x80
[c000000058eab6e0] c000000000509fa8 .migration_call+0x5fc/0x6f8
[c000000058eab7c0] c000000000504074 .notifier_call_chain+0x68/0xe0
[c000000058eab860] c000000000506568 ._cpu_down+0x2b0/0x3f4
[c000000058eaba60] c000000000506750 .cpu_down+0xa4/0x108
[c000000058eabb10] c000000000507e54 .store_online+0x44/0xa8
[c000000058eabba0] c000000000396260 .sysdev_store+0x3c/0x50
[c000000058eabc10] c0000000001a39b8 .sysfs_write_file+0x124/0x18c
[c000000058eabcd0] c00000000013061c .vfs_write+0xd0/0x1bc
[c000000058eabd70] c0000000001308a4 .sys_write+0x68/0x114
[c000000058eabe30] c0000000000086b4 syscall_exit+0x0/0x40

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 19:27:03 +01:00
Al Viro
48887e63d6 [PATCH] fix broken timestamps in AVC generated by kernel threads
Timestamp in audit_context is valid only if ->in_syscall is set.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-09 02:27:41 -05:00
Randy Dunlap
7f0ed77d24 [patch 1/1] audit: remove excess kernel-doc
Delete excess kernel-doc notation in kernel/auditsc.c:

Warning(linux-2.6.27-git10//kernel/auditsc.c:1481): Excess function parameter or struct member 'tsk' description in 'audit_syscall_entry'
Warning(linux-2.6.27-git10//kernel/auditsc.c:1564): Excess function parameter or struct member 'tsk' description in 'audit_syscall_exit'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-09 02:27:40 -05:00
Al Viro
a64e64944f [PATCH] return records for fork() both to child and parent
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-09 02:27:38 -05:00
Eric Paris
a3f07114e3 [PATCH] Audit: make audit=0 actually turn off audit
Currently audit=0 on the kernel command line does absolutely nothing.
Audit always loads and always uses its resources such as creating the
kernel netlink socket.  This patch causes audit=0 to actually disable
audit.  Audit will use no resources and starting the userspace auditd
daemon will not cause the kernel audit system to activate.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-09 02:27:37 -05:00
Yinghai Lu
99d093d128 x86: use NR_IRQS_LEGACY
Impact: cleanup

Introduce NR_IRQS_LEGACY instead of hard coded number.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08 14:31:52 +01:00
Yinghai Lu
0b8f1efad3 sparse irq_desc[] array: core kernel and x86 changes
Impact: new feature

Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.

To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.

When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).

This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08 14:31:51 +01:00
Linus Torvalds
bbeba4c35c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev:
  [PATCH] fix bogus argument of blkdev_put() in pktcdvd
  [PATCH 2/2] documnt FMODE_ constants
  [PATCH 1/2] kill FMODE_NDELAY_NOW
  [PATCH] clean up blkdev_get a little bit
  [PATCH] Fix block dev compat ioctl handling
  [PATCH] kill obsolete temporary comment in swsusp_close()
2008-12-04 21:45:44 -08:00
Linus Torvalds
4857339d7c Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  time: catch xtime_nsec underflows and fix them
  posix-cpu-timers: fix clock_gettime with CLOCK_PROCESS_CPUTIME_ID
2008-12-04 21:40:29 -08:00
Linus Torvalds
3b666ce6a2 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:
  check_hung_task(): unsigned sysctl_hung_task_warnings cannot be less than 0
  documentation: local_ops fix on_each_cpu
2008-12-04 21:39:41 -08:00
Al Viro
50c396d38c [PATCH] kill obsolete temporary comment in swsusp_close()
it had been put there to mark the call of blkdev_put() that
needed proper argument propagated to it; later patch in the
same series had done just that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-04 04:22:54 -05:00
john stultz
6c9bacb41c time: catch xtime_nsec underflows and fix them
Impact: fix time warp bug

Alex Shi, along with Yanmin Zhang have been noticing occasional time
inconsistencies recently. Through their great diagnosis, they found that
the xtime_nsec value used in update_wall_time was occasionally going
negative. After looking through the code for awhile, I realized we have
the possibility for an underflow when three conditions are met in
update_wall_time():

  1) We have accumulated a second's worth of nanoseconds, so we
     incremented xtime.tv_sec and appropriately decrement xtime_nsec.
     (This doesn't cause xtime_nsec to go negative, but it can cause it
      to be small).

  2) The remaining offset value is large, but just slightly less then
     cycle_interval.

  3) clocksource_adjust() is speeding up the clock, causing a
     corrective amount (compensating for the increase in the multiplier
     being multiplied against the unaccumulated offset value) to be
     subtracted from xtime_nsec.

This can cause xtime_nsec to underflow.

Unfortunately, since we notify the NTP subsystem via second_overflow()
whenever we accumulate a full second, and this effects the error
accumulation that has already occured, we cannot simply revert the
accumulated second from xtime nor move the second accumulation to after
the clocksource_adjust call without a change in behavior.

This leaves us with (at least) two options:

1) Simply return from clocksource_adjust() without making a change if we
   notice the adjustment would cause xtime_nsec to go negative.

This would work, but I'm concerned that if a large adjustment was needed
(due to the error being large), it may be possible to get stuck with an
ever increasing error that becomes too large to correct (since it may
always force xtime_nsec negative). This may just be paranoia on my part.

2) Catch xtime_nsec if it is negative, then add back the amount its
   negative to both xtime_nsec and the error.

This second method is consistent with how we've handled earlier rounding
issues, and also has the benefit that the error being added is always in
the oposite direction also always equal or smaller then the correction
being applied. So the risk of a corner case where things get out of
control is lessened.

This patch fixes bug 11970, as tested by Yanmin Zhang
http://bugzilla.kernel.org/show_bug.cgi?id=11970

Reported-by: alex.shi@intel.com
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-04 08:43:02 +01:00
Roel Kluin
201955463a check_hung_task(): unsigned sysctl_hung_task_warnings cannot be less than 0
Impact: fix warnings-limit cutoff check for debug feature

unsigned sysctl_hung_task_warnings cannot be less than 0

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03 10:11:51 +01:00
David Brownell
f2b662da8d genirq: record IRQ_LEVEL in irq_desc[]
Impact: fix __irq_set_trigger() for IRQ_LEVEL

When recording the irq trigger type, let's also make sure
that IRQ_LEVEL gets set correctly.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-02 11:20:46 +01:00
Arjan van de Ven
a800599283 taint: add missing comment
The description for 'D' was missing in the comment...  (causing me a
minute of WTF followed by looking at more of the code)

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01 19:55:24 -08:00
Davide Libenzi
7ef9964e6d epoll: introduce resource usage limits
It has been thought that the per-user file descriptors limit would also
limit the resources that a normal user can request via the epoll
interface.  Vegard Nossum reported a very simple program (a modified
version attached) that can make a normal user to request a pretty large
amount of kernel memory, well within the its maximum number of fds.  To
solve such problem, default limits are now imposed, and /proc based
configuration has been introduced.  A new directory has been created,
named /proc/sys/fs/epoll/ and inside there, there are two configuration
points:

  max_user_instances = Maximum number of devices - per user

  max_user_watches   = Maximum number of "watched" fds - per user

The current default for "max_user_watches" limits the memory used by epoll
to store "watches", to 1/32 of the amount of the low RAM.  As example, a
256MB 32bit machine, will have "max_user_watches" set to roughly 90000.
That should be enough to not break existing heavy epoll users.  The
default value for "max_user_instances" is set to 128, that should be
enough too.

This also changes the userspace, because a new error code can now come out
from EPOLL_CTL_ADD (-ENOSPC).  The EMFILE from epoll_create() was already
listed, so that should be ok.

[akpm@linux-foundation.org: use get_current_user()]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: <stable@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Reported-by: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01 19:55:24 -08:00
Linus Torvalds
9bd062d9ea 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: prevent divide by zero error in cpu_avg_load_per_task, update
  sched, cpusets: fix warning in kernel/cpuset.c
  sched: prevent divide by zero error in cpu_avg_load_per_task
2008-11-30 13:06:47 -08:00
Linus Torvalds
72244c0e68 Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  irq.h: fix missing/extra kernel-doc
  genirq: __irq_set_trigger: change pr_warning to pr_debug
  irq: fix typo
  x86: apic honour irq affinity which was set in early boot
  genirq: fix the affinity setting in setup_irq
  genirq: keep affinities set from userspace across free/request_irq()
2008-11-30 13:06:20 -08:00
Linus Torvalds
93b10052f9 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:
  lockdep: consistent alignement for lockdep info
2008-11-30 13:05:46 -08:00
Linus Torvalds
7bbc67fbf6 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:
  ftrace: prevent recursion
  tracing, doc: update mmiotrace documentation
  x86, mmiotrace: fix buffer overrun detection
  function tracing: fix wrong position computing of stack_trace
2008-11-30 13:05:31 -08:00
Christoph Hellwig
96b8936a9e remove __ARCH_WANT_COMPAT_SYS_PTRACE
All architectures now use the generic compat_sys_ptrace, as should every
new architecture that needs 32bit compat (if we'll ever get another).

Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also
kill a comment about __ARCH_SYS_PTRACE that was added after
__ARCH_SYS_PTRACE was already gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-30 11:00:15 -08:00
Al Viro
8419641450 cpuinit fixes in kernel/*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-30 10:03:37 -08:00
Ingo Molnar
af6d596fd6 sched: prevent divide by zero error in cpu_avg_load_per_task, update
Regarding the bug addressed in:

  4cd4262: sched: prevent divide by zero error in cpu_avg_load_per_task

Linus points out that the fix is not complete:

> There's nothing that keeps gcc from deciding not to reload
> rq->nr_running.
>
> Of course, in _practice_, I don't think gcc ever will (if it decides
> that it will spill, gcc is likely going to decide that it will
> literally spill the local variable to the stack rather than decide to
> reload off the pointer), but it's a valid compiler optimization, and
> it even has a name (rematerialization).
>
> So I suspect that your patch does fix the bug, but it still leaves the
> fairly unlikely _potential_ for it to re-appear at some point.
>
> We have ACCESS_ONCE() as a macro to guarantee that the compiler
> doesn't rematerialize a pointer access. That also would clarify
> the fact that we access something unsafe outside a lock.

So make sure our nr_running value is immutable and cannot change
after we check it for nonzero.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-29 20:45:15 +01:00
Ingo Molnar
1583715ddb sched, cpusets: fix warning in kernel/cpuset.c
this warning:

  kernel/cpuset.c: In function ‘generate_sched_domains’:
  kernel/cpuset.c:588: warning: ‘ndoms’ may be used uninitialized in this function

triggers because GCC does not recognize that ndoms stays uninitialized
only if doms is NULL - but that flow is covered at the end of
generate_sched_domains().

Help out GCC by initializing this variable to 0. (that's prudent anyway)

Also, this function needs a splitup and code flow simplification:
with 160 lines length it's clearly too long.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-29 20:39:29 +01:00
Steven Rostedt
4cd4262034 sched: prevent divide by zero error in cpu_avg_load_per_task
Impact: fix divide by zero crash in scheduler rebalance irq

While testing the branch profiler, I hit this crash:

divide error: 0000 [#1] PREEMPT SMP
[...]
RIP: 0010:[<ffffffff8024a008>]  [<ffffffff8024a008>] cpu_avg_load_per_task+0x50/0x7f
[...]
Call Trace:
 <IRQ> <0> [<ffffffff8024fd43>] find_busiest_group+0x3e5/0xcaa
 [<ffffffff8025da75>] rebalance_domains+0x2da/0xa21
 [<ffffffff80478769>] ? find_next_bit+0x1b2/0x1e6
 [<ffffffff8025e2ce>] run_rebalance_domains+0x112/0x19f
 [<ffffffff8026d7c2>] __do_softirq+0xa8/0x232
 [<ffffffff8020ea7c>] call_softirq+0x1c/0x3e
 [<ffffffff8021047a>] do_softirq+0x94/0x1cd
 [<ffffffff8026d5eb>] irq_exit+0x6b/0x10e
 [<ffffffff8022e6ec>] smp_apic_timer_interrupt+0xd3/0xff
 [<ffffffff8020e4b3>] apic_timer_interrupt+0x13/0x20

The code for cpu_avg_load_per_task has:

	if (rq->nr_running)
		rq->avg_load_per_task = rq->load.weight / rq->nr_running;

The runqueue lock is not held here, and there is nothing that prevents
the rq->nr_running from going to zero after it passes the if condition.

The branch profiler simply made the race window bigger.

This patch saves off the rq->nr_running to a local variable and uses that
for both the condition and the division.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-27 10:29:52 +01:00
Lai Jiangshan
4f5a7f40dd ftrace: prevent recursion
Impact: prevent unnecessary stack recursion

if the resched flag was set before we entered, then don't reschedule.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-27 10:11:53 +01:00
Petr Tesarik
eccdaeafae posix-cpu-timers: fix clock_gettime with CLOCK_PROCESS_CPUTIME_ID
Since CLOCK_PROCESS_CPUTIME_ID is in fact translated to -6, the switch
statement in cpu_clock_sample_group() must first mask off the irrelevant
bits, similar to cpu_clock_sample().

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

--
 posix-cpu-timers.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
2008-11-24 16:41:40 +01:00
Pekka Paalanen
7ee1768ddb x86, mmiotrace: fix buffer overrun detection
Impact: fix mmiotrace overrun tracing

When ftrace framework moved to use the ring buffer facility, the buffer
overrun detection was broken after 2.6.27 by commit

| commit 3928a8a2d9
| Author: Steven Rostedt <rostedt@goodmis.org>
| Date:   Mon Sep 29 23:02:41 2008 -0400
|
|     ftrace: make work with new ring buffer
|
|     This patch ports ftrace over to the new ring buffer.

The detection is now fixed by using the ring buffer API.

When mmiotrace detects a buffer overrun, it will report the number of
lost events. People reading an mmiotrace log must know if something was
missed, otherwise the data may not make sense.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 20:33:23 +01:00
Ingo Molnar
9f14416442 Merge commit 'v2.6.28-rc6' into irq/urgent 2008-11-23 10:52:33 +01:00
Li Zefan
b0788caf7a lockdep: consistent alignement for lockdep info
Impact: prettify /proc/lockdep_info

Just feel odd that not all lines of lockdep info are aligned.

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>
2008-11-21 08:59:40 +01:00
Liming Wang
522a110b42 function tracing: fix wrong position computing of stack_trace
Impact: make output of stack_trace complete if buffer overruns

When read buffer overruns, the output of stack_trace isn't complete.

When printing records with seq_printf in t_show, if the read buffer
has overruned by the current record, then this record won't be
printed to user space through read buffer, it will just be dropped in
this printing.

When next printing, t_start should return the "*pos"th record, which
is the one dropped by previous printing, but it just returns
(m->private + *pos)th record.

Here we use a more sane method to implement seq_operations which can
be found in kernel code. Thus we needn't initialize m->private.

About testing, it's not easy to overrun read buffer, but we can use
seq_printf to print more padding bytes in t_show, then it's easy to
check whether or not records are lost.

This commit has been tested on both condition of overrun and non
overrun.

Signed-off-by: Liming Wang <liming.wang@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-21 08:49:52 +01:00