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Author SHA1 Message Date
Linus Torvalds
0ba6c33bcd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25: (1470 commits)
  [IPV6] ADDRLABEL: Fix double free on label deletion.
  [PPP]: Sparse warning fixes.
  [IPV4] fib_trie: remove unneeded NULL check
  [IPV4] fib_trie: More whitespace cleanup.
  [NET_SCHED]: Use nla_policy for attribute validation in ematches
  [NET_SCHED]: Use nla_policy for attribute validation in actions
  [NET_SCHED]: Use nla_policy for attribute validation in classifiers
  [NET_SCHED]: Use nla_policy for attribute validation in packet schedulers
  [NET_SCHED]: sch_api: introduce constant for rate table size
  [NET_SCHED]: Use typeful attribute parsing helpers
  [NET_SCHED]: Use typeful attribute construction helpers
  [NET_SCHED]: Use NLA_PUT_STRING for string dumping
  [NET_SCHED]: Use nla_nest_start/nla_nest_end
  [NET_SCHED]: Propagate nla_parse return value
  [NET_SCHED]: act_api: use PTR_ERR in tcf_action_init/tcf_action_get
  [NET_SCHED]: act_api: use nlmsg_parse
  [NET_SCHED]: act_api: fix netlink API conversion bug
  [NET_SCHED]: sch_netem: use nla_parse_nested_compat
  [NET_SCHED]: sch_atm: fix format string warning
  [NETNS]: Add namespace for ICMP replying code.
  ...
2008-01-29 22:54:01 +11:00
Greg Kroah-Hartman
6494a93d55 Module: check to see if we have a built in module with the same name
When trying to load a module with the same name as a built-in one, a
scary kobject backtrace comes up.  Prevent that from checking for this
condition and warning the user as to what exactly is going on.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:27 +11:00
Jon Masters
0aa5bd52d0 module: add module taint on ndiswrapper
The struct module taints member is supposed to store per-module taint
data. The kernel knows about certain specific external modules that will
taint the kernel, such as ndiswrapper. Use of ndiswrapper possibly
should set the per-module taint in addition to the global kernel
taint flag, unless we're arguing not because wrapper module itself
is not what actually causes the kernel to be tainted as such?

Signed-off-by: Jon Masters <jcm@jonmasters.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:26 +11:00
Denis Cheng
8686c99875 module: fix the module name length in param_sysfs_builtin
the original code use KOBJ_NAME_LEN for built-in module name length,
that's defined to 20 in linux/kobject.h, but this is not enough appearntly,
many module names are longer than this;
 #define KOBJ_NAME_LEN                   20

another macro is MODULE_NAME_LEN defined in linux/module.h, I think this is
enough for module names:
 #define MODULE_NAME_LEN (64 - sizeof(unsigned long))

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:24 +11:00
Rusty Russell
6dd06c9fbe module: make module_address_lookup safe
module_address_lookup releases preemption then returns a pointer into
the module space.  The only user (kallsyms) copies the result, so just
do that under the preempt disable.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:23 +11:00
Rusty Russell
bb9d3d56e7 module: better OOPS and lockdep coverage for loading modules
If we put the module in the linked list *before* calling into to, we
get the module name and functions in the OOPS (is_module_address can
find the module).  It also helps lockdep in a similar way.

Acked-and-tested-by: Joern Engel <joern@lazybastard.org>
Tested-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:22 +11:00
Rusty Russell
efa5345e39 module: Fix gratuitous sprintf in module.c
Andrew sent an older version of this patch: we shouldn't use sprintf
to copy a string.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:21 +11:00
Rusty Russell
c9a3ba55bb module: wait for dependent modules doing init.
There have been reports of modules failing to load because the modules
they depend on are still loading.  This changes the modules to wait
for a reasonable length of time in that case.  We time out eventually,
because there can be module loops or broken modules.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:20 +11:00
Rusty Russell
a2da4052f1 module: Don't report discarded init pages as kernel text.
Current code could cause a bug in symbol_put_addr() if an arch used
kmalloc module text: we might think the symbol belongs to the core
kernel.

The downside is that this might make backtraces through (discarded)
init functions harder to read on some archs, but we already have that
issue for modules and noone has complained.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:18 +11:00
Pavel Emelyanov
08913681e4 [NET]: Remove the empty net_table
I have removed all the entries from this table (core_table,
ipv4_table and tr_table), so now we can safely drop it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:56:29 -08:00
Eric W. Biederman
e51b6ba077 sysctl: Infrastructure for per namespace sysctls
This patch implements the basic infrastructure for per namespace sysctls.

A list of lists of sysctl headers is added, allowing each namespace to have
it's own list of sysctl headers.

Each list of sysctl headers has a lookup function to find the first
sysctl header in the list, allowing the lists to have a per namespace
instance.

register_sysct_root is added to tell sysctl.c about additional
lists of sysctl_headers.  As all of the users are expected to be in
kernel no unregister function is provided.

sysctl_head_next is updated to walk through the list of lists.

__register_sysctl_paths is added to add a new sysctl table on
a non-default sysctl list.

The only intrusive part of this patch is propagating the information
to decided which list of sysctls to use for sysctl_check_table.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:17 -08:00
Eric W. Biederman
23eb06de7d sysctl: Remember the ctl_table we passed to register_sysctl_paths
By doing this we allow users of register_sysctl_paths that build
and dynamically allocate their ctl_table to be simpler.  This allows
them to just remember the ctl_table_header returned from
register_sysctl_paths from which they can now find the
ctl_table array they need to free.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:17 -08:00
Eric W. Biederman
29e796fd4d sysctl: Add register_sysctl_paths function
There are a number of modules that register a sysctl table
somewhere deeply nested in the sysctl hierarchy, such as
fs/nfs, fs/xfs, dev/cdrom, etc.

They all specify several dummy ctl_tables for the path name.
This patch implements register_sysctl_path that takes
an additional path name, and makes up dummy sysctl nodes
for each component.

This patch was originally written by Olaf Kirch and
brought to my attention and reworked some by Olaf Hering.
I have changed a few additional things so the bugs are mine.

After converting all of the easy callers Olaf Hering observed
allyesconfig ARCH=i386, the patch reduces the final binary size by 9369 bytes.

.text +897
.data -7008

   text    data     bss     dec     hex filename
   26959310        4045899 4718592 35723801        2211a19 ../vmlinux-vanilla
   26960207        4038891 4718592 35717690        221023a ../O-allyesconfig/vmlinux

So this change is both a space savings and a code simplification.

CC: Olaf Kirch <okir@suse.de>
CC: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:16 -08:00
Jens Axboe
fadad878cc kernel: add CLONE_IO to specifically request sharing of IO contexts
syslets (or other threads/processes that want io context sharing) can
set this to enforce sharing of io context.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:50:36 +01:00
Jens Axboe
d38ecf935f io context sharing: preliminary support
Detach task state from ioc, instead keep track of how many processes
are accessing the ioc.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:50:31 +01:00
Jens Axboe
fd0928df98 ioprio: move io priority from task_struct to io_context
This is where it belongs and then it doesn't take up space for a
process that doesn't do IO.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:50:29 +01:00
Ingo Molnar
326e96b923 printk: revert ktime_get() timestamps
revert 19ef930927.

Kevin Winchester reported a lockup during X startup an bisected
it to this commit.

Reported-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-27 08:03:54 +01:00
Heiko Carstens
81ef16e763 [S390] Remove appldata include from sysctl_check.c
Forgot to remove this when removing the appldata binary sysctls.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26 14:11:16 +01:00
Linus Torvalds
9b73e76f3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (200 commits)
  [SCSI] usbstorage: use last_sector_bug flag universally
  [SCSI] libsas: abstract STP task status into a function
  [SCSI] ultrastor: clean up inline asm warnings
  [SCSI] aic7xxx: fix firmware build
  [SCSI] aacraid: fib context lock for management ioctls
  [SCSI] ch: remove forward declarations
  [SCSI] ch: fix device minor number management bug
  [SCSI] ch: handle class_device_create failure properly
  [SCSI] NCR5380: fix section mismatch
  [SCSI] sg: fix /proc/scsi/sg/devices when no SCSI devices
  [SCSI] IB/iSER: add logical unit reset support
  [SCSI] don't use __GFP_DMA for sense buffers if not required
  [SCSI] use dynamically allocated sense buffer
  [SCSI] scsi.h: add macro for enclosure bit of inquiry data
  [SCSI] sd: add fix for devices with last sector access problems
  [SCSI] fix pcmcia compile problem
  [SCSI] aacraid: add Voodoo Lite class of cards.
  [SCSI] aacraid: add new driver features flags
  [SCSI] qla2xxx: Update version number to 8.02.00-k7.
  [SCSI] qla2xxx: Issue correct MBC_INITIALIZE_FIRMWARE command.
  ...
2008-01-25 17:19:08 -08:00
Arjan van de Ven
6d082592b6 sched: keep total / count stats in addition to the max for
Right now, the linux kernel (with scheduler statistics enabled) keeps track
of the maximum time a process is waiting to be scheduled. While the maximum
is a very useful metric, tracking average and total is equally useful
(at least for latencytop) to figure out the accumulated effect of scheduler
delays. The accumulated effect is important to judge the performance impact
of scheduler tuning/behavior.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:35 +01:00
Peter Zijlstra
5973e5b954 sched: fix: don't take a mutex from interrupt context
print_cfs_stats is callable from interrupt context (sysrq), hence it should
not take mutexes. Change it to use RCU since the task group data is RCU
freed anyway.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Nick Piggin
5fb5e6de55 sched: print backtrace of running tasks too
The attached patch is something really simple that can sometimes help
in getting more info out of a hung system.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Ingo Molnar
19ef930927 printk: use ktime_get()
printk timestamps: use ktime_get().

Some platforms have a functioning clocksource function only after
they are done with early bootup, so delay this until out of
SYSTEM_BOOTING state.

it's also inherently safe now, as any bugs in this area will be
caught by the printk recursion checks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Ingo Molnar
90739081ef softlockup: fix signedness
fix softlockup tunables signedness.

mark tunables read-mostly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Arjan van de Ven
9745512ce7 sched: latencytop support
LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Dmitry Adamushko
326587b840 sched: fix goto retry in pick_next_task_rt()
looking at it one more time:

(1) it looks to me that there is no need to call
sched_rt_ratio_exceeded() from pick_next_rt_entity()

- [ for CONFIG_FAIR_GROUP_SCHED ] queues with rt_rq->rt_throttled are
not within this 'tree-like hierarchy' (or whatever we should call it
:-)

- there is also no need to re-check 'rt_rq->rt_time > ratio' at this
point as 'rt_rq->rt_time' couldn't have been increased since the last
call to update_curr_rt() (which obviously calls
sched_rt_ratio_esceeded())
well, it might be that 'ratio' for this rt_rq has been re-configured
(and the period over which this rt_rq was active has not yet been
finished)... but I don't think we should really take this into
account.

(2) now pick_next_rt_entity() must never return NULL, so let's change
pick_next_task_rt() accordingly.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Guillaume Chazarain
cc203d2422 sched: monitor clock underflows in /proc/sched_debug
We monitor clock overflows, let's also monitor clock underflows.

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Guillaume Chazarain
782daeee3d sched: fix rq->clock warps on frequency changes
sched: fix rq->clock warps on frequency changes

Fix 2bacec8c31
(sched: touch softlockup watchdog after idling) that reintroduced warps
on frequency changes. touch_softlockup_watchdog() calls __update_rq_clock
that checks rq->clock for warps, so call it after adjusting rq->clock.

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Michal Schmidt
4f05b98d54 sched: fix, always create kernel threads with normal priority
Ensure that the kernel threads are created with the usual nice level
and affinity even if kthreadd's properties were changed from the
default by root.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Paolo Ciarrocchi
1ad82fd547 debug: clean up kernel/profile.c
Before:
 total: 25 errors, 13 warnings, 602 lines checked

 After:
 total: 0 errors, 2 warnings, 601 lines checked

No code changed:

kernel/profile.o:
   text    data     bss     dec     hex filename
   3048     236      24    3308     cec profile.o.before
   3048     236      24    3308     cec profile.o.after
 md5:
   2501d64748a4d350dffb11203e2a5182  profile.o.before.asm
   2501d64748a4d350dffb11203e2a5182  profile.o.after.asm

Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Ingo Molnar
6478d8800b sched: remove the !PREEMPT_BKL code
remove the !PREEMPT_BKL code.

this removes 160 lines of legacy code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Ingo Molnar
58b8a73ab8 sched: make PREEMPT_BKL the default
make PREEMPT_BKL the default.

precursor to removal of the !PREEMPT_BKL code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Arjan van de Ven
e14af7eeb4 debug: track and print last unloaded module in the oops trace
Based on a suggestion from Andi:

 In various cases, the unload of a module may leave some bad state around
 that causes a kernel crash AFTER a module is unloaded; and it's then hard
 to find which module caused that.

This patch tracks the last unloaded module, and prints this as part of the
module list in the oops trace.

Right now, only the last 1 module is tracked; I expect that this is enough
for the vast majority of cases where this information matters; if it turns
out that tracking more is important, we can always extend it to that.

[ mingo@elte.hu: build fix ]

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Arjan van de Ven
21aa9280b9 debug: show being-loaded/being-unloaded indicator for modules
It's rather common that an oops/WARN_ON/BUG happens during the load or
unload of a module. Unfortunatly, it's not always easy to see directly
which module is being loaded/unloaded from the oops itself. Worse,
it's not even always possible to ask the bug reporter, since there
are so many components (udev etc) that auto-load modules that there's
a good chance that even the reporter doesn't know which module this is.

This patch extends the existing "show if it's tainting" print code,
which is used as part of printing the modules in the oops/BUG/WARN_ON
to include a "+" for "being loaded" and a "-" for "being unloaded".

As a result this extension, the "taint_flags()" function gets renamed to
"module_flags()" (and takes a module struct as argument, not a taint
flags int).

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:33 +01:00
Peter Zijlstra
5a52dd5009 sched: rt-watchdog: fix .rlim_max = RLIM_INFINITY
Remove the curious logic to set it_sched_expires in the future. It useless
because rt.timeout wouldn't be incremented anyway.

Explicity check for RLIM_INFINITY as a test programm that had a 1s soft limit
and a inf hard limit would SIGKILL at 1s. This is because RLIM_INFINITY+d-1
is d-2.

Signed-off-by: Peter Zijlsta <a.p.zijlstra@chello.nl>
CC: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:32 +01:00
Peter Zijlstra
1020387f5f sched: rt-group: reduce rescheduling
Only reschedule if the new group has a higher prio task.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:32 +01:00
Peter Zijlstra
37bb6cb409 hrtimer: unlock hrtimer_wakeup
hrtimer_wakeup creates a

  base->lock
    rq->lock

lock dependancy. Avoid this by switching to HRTIMER_CB_IRQSAFE_NO_SOFTIRQ
which doesn't hold base->lock.

This fully untangles hrtimer locks from the scheduler locks, and allows
hrtimer usage in the scheduler proper.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:32 +01:00
Peter Zijlstra
d3d74453c3 hrtimer: fixup the HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallback
Currently all highres=off timers are run from softirq context, but
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ timers expect to run from irq context.

Fix this up by splitting it similar to the highres=on case.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Peter Zijlstra
2d44ae4d71 hrtimer: clean up cpu->base locking tricks
In order to more easily allow for the scheduler to use timers, clean up
the locking a bit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Peter Zijlstra
48d5e25821 sched: rt throttling vs no_hz
We need to teach no_hz about the rt throttling because its tick driven.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:31 +01:00
Mike Galbraith
614ee1f61f sched: pull_rt_task() cleanup
"goto out" is an odd way to spell "skip".

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:30 +01:00
Peter Zijlstra
6f505b1642 sched: rt group scheduling
Extend group scheduling to also cover the realtime classes. It uses the time
limiting introduced by the previous patch to allow multiple realtime groups.

The hard time limit is required to keep behaviour deterministic.

The algorithms used make the realtime scheduler O(tg), linear scaling wrt the
number of task groups. This is the worst case behaviour I can't seem to get out
of, the avg. case of the algorithms can be improved, I focused on correctness
and worst case.

[ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:30 +01:00
Peter Zijlstra
fa85ae2418 sched: rt time limit
Very simple time limit on the realtime scheduling classes.
Allow the rq's realtime class to consume sched_rt_ratio of every
sched_rt_period slice. If the class exceeds this quota the fair class
will preempt the realtime class.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:29 +01:00
Peter Zijlstra
8f4d37ec07 sched: high-res preemption tick
Use HR-timers (when available) to deliver an accurate preemption tick.

The regular scheduler tick that runs at 1/HZ can be too coarse when nice
level are used. The fairness system will still keep the cpu utilisation 'fair'
by then delaying the task that got an excessive amount of CPU time but try to
minimize this by delivering preemption points spot-on.

The average frequency of this extra interrupt is sched_latency / nr_latency.
Which need not be higher than 1/HZ, its just that the distribution within the
sched_latency period is important.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:29 +01:00
Herbert Xu
02b67cc3ba sched: do not do cond_resched() when CONFIG_PREEMPT
Why do we even have cond_resched when real preemption
is on? It seems to be a waste of space and time.

remove cond_resched with CONFIG_PREEMPT on.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:28 +01:00
Ingo Molnar
03319ec8b0 sched: documentation, whitespace fixes
whitespace fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:28 +01:00
Peter Zijlstra
78f2c7db60 sched: SCHED_FIFO/SCHED_RR watchdog timer
Introduce a new rlimit that allows the user to set a runtime timeout on
real-time tasks their slice. Once this limit is exceeded the task will receive
SIGXCPU.

So it measures runtime since the last sleep.

Input and ideas by Thomas Gleixner and Lennart Poettering.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Lennart Poettering <mzxreary@0pointer.de>
CC: Michael Kerrisk <mtk.manpages@googlemail.com>
CC: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:27 +01:00
Peter Zijlstra
fa717060f1 sched: sched_rt_entity
Move the task_struct members specific to rt scheduling together.
A future optimization could be to put sched_entity and sched_rt_entity
into a union.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:27 +01:00
Pavel Emelyanov
8eb703e4f3 uids: merge multiple error paths in alloc_uid() into one
There are already 4 error paths in alloc_uid() that do incremental rollbacks.
I think it's time to merge them.  This costs us 8 lines of code :)

Maybe it would be better to merge this patch with the previous one, but I
remember that some time ago I sent a similar patch (fixing the error path and
cleaning it), but I was told to make two patches in such cases.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:26 +01:00
Gregory Haskins
dc938520d2 sched: dynamically update the root-domain span/online maps
The baseline code statically builds the span maps when the domain is formed.
Previous attempts at dynamically updating the maps caused a suspend-to-ram
regression, which should now be fixed.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:26 +01:00