28 Jan, 2008
3 commits
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syslets (or other threads/processes that want io context sharing) can
set this to enforce sharing of io context.Signed-off-by: Jens Axboe
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Detach task state from ioc, instead keep track of how many processes
are accessing the ioc.Signed-off-by: Jens Axboe
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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
27 Jan, 2008
1 commit
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revert 19ef9309273d26cb005cb23e6a370353dca91099.
Kevin Winchester reported a lockup during X startup an bisected
it to this commit.Reported-by: Kevin Winchester
Signed-off-by: Ingo Molnar
26 Jan, 2008
36 commits
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Forgot to remove this when removing the appldata binary sysctls.
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
* 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.
... -
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
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
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
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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
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fix softlockup tunables signedness.
mark tunables read-mostly.
Signed-off-by: Ingo Molnar
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LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.Signed-off-by: Arjan van de Ven
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
We monitor clock overflows, let's also monitor clock underflows.
Signed-off-by: Guillaume Chazarain
Signed-off-by: Ingo Molnar -
sched: fix rq->clock warps on frequency changes
Fix 2bacec8c318ca0418c0ee9ac662ee44207765dd4
(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
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
Before:
total: 25 errors, 13 warnings, 602 lines checkedAfter:
total: 0 errors, 2 warnings, 601 lines checkedNo 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.asmSigned-off-by: Paolo Ciarrocchi
Signed-off-by: Ingo Molnar -
remove the !PREEMPT_BKL code.
this removes 160 lines of legacy code.
Signed-off-by: Ingo Molnar
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make PREEMPT_BKL the default.
precursor to removal of the !PREEMPT_BKL code.
Signed-off-by: Ingo Molnar
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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
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
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
CC: Michal Schmidt
Signed-off-by: Ingo Molnar -
Only reschedule if the new group has a higher prio task.
Signed-off-by: Peter Zijlstra
Signed-off-by: Ingo Molnar -
hrtimer_wakeup creates a
base->lock
rq->locklock 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
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
In order to more easily allow for the scheduler to use timers, clean up
the locking a bit.Signed-off-by: Peter Zijlstra
Signed-off-by: Ingo Molnar -
We need to teach no_hz about the rt throttling because its tick driven.
Signed-off-by: Peter Zijlstra
Signed-off-by: Ingo Molnar -
"goto out" is an odd way to spell "skip".
Signed-off-by: Mike Galbraith
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Ingo Molnar -
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
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whitespace fixes.
Signed-off-by: Ingo Molnar
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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
CC: Lennart Poettering
CC: Michael Kerrisk
CC: Ulrich Drepper
Signed-off-by: Ingo Molnar -
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
CC: Srivatsa Vaddagiri
Signed-off-by: Ingo Molnar -
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
Acked-by: Dhaval Giani
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar -
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
CC: Gautham R Shenoy
Signed-off-by: Ingo Molnar -
This patch allows preemptible RCU to tolerate CPU-hotplug operations.
It accomplishes this by maintaining a local copy of a map of online
CPUs, which it accesses under its own lock.Signed-off-by: Gautham R Shenoy
Signed-off-by: Paul E. McKenney
Reviewed-by: Steven Rostedt
Signed-off-by: Ingo Molnar -
This patch implements a new version of RCU which allows its read-side
critical sections to be preempted. It uses a set of counter pairs
to keep track of the read-side critical sections and flips them
when all tasks exit read-side critical section. The details
of this implementation can be found in this paper -http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf
and the article-
http://lwn.net/Articles/253651/
This patch was developed as a part of the -rt kernel development and
meant to provide better latencies when read-side critical sections of
RCU don't disable preemption. As a consequence of keeping track of RCU
readers, the readers have a slight overhead (optimizations in the paper).
This implementation co-exists with the "classic" RCU implementations
and can be switched to at compiler.Also includes RCU tracing summarized in debugfs.
[ akpm@linux-foundation.org: build fixes on non-preempt architectures ]
Signed-off-by: Gautham R Shenoy
Signed-off-by: Dipankar Sarma
Signed-off-by: Paul E. McKenney
Reviewed-by: Steven Rostedt
Signed-off-by: Ingo Molnar -
Fix rcu_barrier() to work properly in preemptive kernel environment.
Also, the ordering of callback must be preserved while moving
callbacks to another CPU during CPU hotplug.Signed-off-by: Gautham R Shenoy
Signed-off-by: Dipankar Sarma
Signed-off-by: Paul E. McKenney
Reviewed-by: Steven Rostedt
Signed-off-by: Ingo Molnar
