GROUP_SCHED is confirmed to cause unacceptable latencies, see:
http://lkml.org/lkml/2008/5/2/370.
Mark it EXPERIMENTAL and default to no for now.
Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
this replaces the rq->clock stuff (and possibly cpu_clock()).
- architectures that have an 'imperfect' hardware clock can set
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
- the 'jiffie' window might be superfulous when we update tick_gtod
before the __update_sched_clock() call in sched_clock_tick()
- cpu_clock() might be implemented as:
sched_clock_cpu(smp_processor_id())
if the accuracy proves good enough - how far can TSC drift in a
single jiffie when considering the filtering and idle hooks?
[ mingo@elte.hu: various fixes and cleanups ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
David Miller pointed it out that nothing in cpu_clock() sets
prev_cpu_time. This caused __sync_cpu_clock() to be called
all the time - against the intention of this code.
The result was that in practice we hit a global spinlock every
time cpu_clock() is called - which - even though cpu_clock()
is used for tracing and debugging, is suboptimal.
While at it, also:
- move the irq disabling to the outest layer,
this should make cpu_clock() warp-free when called with irqs
enabled.
- use long long instead of cycles_t - for platforms where cycles_t
is 32-bit.
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When I echoed 0 into the "cpu.shares" file, a Div0 error occured.
We found it is caused by the following calling.
sched_group_set_shares(tg, shares)
set_se_shares(tg->se[i], shares/nr_cpu_ids)
__set_se_shares(se, shares)
div64_64((1ULL<<32), shares)
When the echoed value was less than the number of processores, the result of the
sentence "shares/nr_cpu_ids" was 0, and then the system called div64() to divide
the result, the Div0 error occured.
It is unnecessary that the shares value is divided by nr_cpu_ids, I think.
Because in the function __update_group_shares_cpu() and init_tg_cfs_entry(),
the shares value isn't divided by nr_cpu_ids when setting shares of the sched
entity.
This patch fixes this bug. And echoing ULONG_MAX value into cpu.shares also
causes Div0 error, so we set a macro MAX_SHARES to limit the max value of
shares.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Concurrent calls to detach_destroy_domains and arch_init_sched_domains
were prevented by the old scheduler subsystem cpu hotplug mutex. When
this got converted to get_online_cpus() the locking got broken.
Unlike before now several processes can concurrently enter the critical
sections that were protected by the old lock.
So use the already present doms_cur_mutex to protect these sections again.
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Revert debugging commit 7ba2e74ab5.
print_cfs_rq_tasks() can induce live-lock if a task is dequeued
during list traversal.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
http://bugzilla.kernel.org/show_bug.cgi?id=10545
sched_stats.h says that __sched_info_switch is "called when prev !=
next" in the comment. sched.c should therefore do that.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Gautham R Shenoy reported:
> While running the usual CPU-Hotplug stress tests on linux-2.6.25,
> I noticed the following in the console logs.
>
> This is a wee bit difficult to reproduce. In the past 10 runs I hit this
> only once.
>
> ------------[ cut here ]------------
>
> WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65()
>
> Just wondering if we are doing a good job at handling the cancellation
> of any per-cpu scheduler timers during CPU-Hotplug.
This looks like its indeed not cancelled at all and migrates the it to
another cpu. Fix it via a proper hotplug notifier mechanism.
Reported-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We currently use an optimization to skip the overhead of wake-idle
processing if more than one task is assigned to a run-queue. The
assumption is that the system must already be load-balanced or we
wouldnt be overloaded to begin with.
The problem is that we are looking at rq->nr_running, which may include
RT tasks in addition to CFS tasks. Since the presence of RT tasks
really has no bearing on the balance status of CFS tasks, this throws
the calculation off.
This patch changes the logic to only consider the number of CFS tasks
when making the decision to optimze the wake-idle.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Dmitry Adamushko pointed out a logic error in task_wake_up_rt() where we
will always evaluate to "true". You can find the thread here:
http://lkml.org/lkml/2008/4/22/296
In reality, we only want to try to push tasks away when a wake up request is
not going to preempt the current task. So lets fix it.
Note: We introduce test_tsk_need_resched() instead of open-coding the flag
check so that the merge-conflict with -rt should help remind us that we
may need to support NEEDS_RESCHED_DELAYED in the future, too.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
CC: Dmitry Adamushko <dmitry.adamushko@gmail.com>
CC: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Noticed by sparse:
kernel/sched.c:760:20: warning: symbol 'sched_feat_names' was not declared. Should it be static?
kernel/sched.c:767:5: warning: symbol 'sched_feat_open' was not declared. Should it be static?
kernel/sched_fair.c:845:3: warning: returning void-valued expression
kernel/sched.c:4386:3: warning: returning void-valued expression
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fabio Checconi noticed that Documentation/scheduler/sched-design.txt was
a stale copy of the old scheduler. Remove it.
Reported-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The C files are included directly in sched.c, so they are
effectively static.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Joel noticed that the !lw->inv_weight contition isn't unlikely anymore so
remove the unlikely annotation. Also, remove the two div64_u64() inv_weight
calculations, which makes them rely on the calc_delta_mine() path as well.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Joel Schopp <jschopp@austin.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Normalized sleeper uses calc_delta*() which requires that the rq load is
already updated, so move account_entity_enqueue() before place_entity()
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
dccp_feat_change() validates length and on error is returning 1.
This happens to work since call chain is checking for 0 == success,
but this is returned to userspace, so make it a real error value.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
x86 PCI: call dmi_check_pciprobe()
x86/pci: add pci=skip_isa_align command lines.
x86/pci: remove flag in pci_cfg_space_size_ext
x86: fix section mismatch in pci_scan_bus
The identical online_page() implementations from all architectures got
moved to mm/memory_hotplug.c - except for the sparc64 one that even was
dead code due to MEMORY_HOTPLUG not being available there.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The new mac_esp scsi driver needs CONFIG_SCSI_SPI_ATTRS, just like all other
drivers using the new esp_scsi core.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the rest of the old mac_esp driver. Also ditch the rest of the
machw mechanism, it needs to be replaced by a fake openfirmware tree.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix 68040 bus fault handling, so the standard kernel exception handling
can be used for i/o probing.
Contrary to normal access faults there is nothing to fix, but at least
we have to disable writebacks to avoid recursive faults.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/input/serio/hp_sdc.c: In function 'hp_sdc_take':
drivers/input/serio/hp_sdc.c:198: error: implicit declaration of function 'up'
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kgdb: kconfig fix xconfig/menuconfig element
kgdb: fix signedness mixmatches, add statics, add declaration to header
kgdb: 1000 loops for the single step test in kgdbts
kgdb: trivial sparse fixes in kgdb test-suite
kgdb: minor documentation fixes
this change:
| commit 08f1c192c3
| Author: Muli Ben-Yehuda <muli@il.ibm.com>
| Date: Sun Jul 22 00:23:39 2007 +0300
|
| x86-64: introduce struct pci_sysdata to facilitate sharing of ->sysdata
|
| This patch introduces struct pci_sysdata to x86 and x86-64, and
| converts the existing two users (NUMA, Calgary) to use it.
|
| This lays the groundwork for having other users of sysdata, such as
| the PCI domains work.
|
| The Calgary bits are tested, the NUMA bits just look ok.
replaces pcibios_scan_root with pci_scan_bus_parented...
but in pcibios_scan_root we have a DMI check:
dmi_check_system(pciprobe_dmi_table);
when when have several peer root buses this could be called multiple
times (which is bad), so move that call to pci_access_init().
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
so we don't align the io port start address for pci cards.
also move out dmi check out acpi.c, because it has nothing to do with acpi.
it could spare some calling when we have several peer root buses.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Since FUTEX_FD was scheduled for removal in June 2007 lets remove it.
Google Code search found no users for it and NGPT was abandoned in 2003
according to IBM. futex.h is left untouched to make sure the id does
not get reassigned. Since queue_me() has no users left it is commented
out to avoid a warning, i didnt remove it completely since it is part of
the internal api (matching unqueue_me())
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed rest)
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Noticed by sparse:
arch/x86/kernel/kgdb.c:556:15: warning: symbol 'kgdb_arch_pc' was not declared. Should it be static?
kernel/kgdb.c:149:8: warning: symbol 'kgdb_do_roundup' was not declared. Should it be static?
kernel/kgdb.c:193:22: warning: symbol 'kgdb_arch_pc' was not declared. Should it be static?
kernel/kgdb.c:712:5: warning: symbol 'remove_all_break' was not declared. Should it be static?
Related to kgdb_hex2long:
arch/x86/kernel/kgdb.c:371:28: warning: incorrect type in argument 2 (different signedness)
arch/x86/kernel/kgdb.c:371:28: expected long *long_val
arch/x86/kernel/kgdb.c:371:28: got unsigned long *<noident>
kernel/kgdb.c:469:27: warning: incorrect type in argument 2 (different signedness)
kernel/kgdb.c:469:27: expected long *long_val
kernel/kgdb.c:469:27: got unsigned long *<noident>
kernel/kgdb.c:470:27: warning: incorrect type in argument 2 (different signedness)
kernel/kgdb.c:470:27: expected long *long_val
kernel/kgdb.c:470:27: got unsigned long *<noident>
kernel/kgdb.c:894:27: warning: incorrect type in argument 2 (different signedness)
kernel/kgdb.c:894:27: expected long *long_val
kernel/kgdb.c:894:27: got unsigned long *<noident>
kernel/kgdb.c:895:27: warning: incorrect type in argument 2 (different signedness)
kernel/kgdb.c:895:27: expected long *long_val
kernel/kgdb.c:895:27: got unsigned long *<noident>
kernel/kgdb.c:1127:28: warning: incorrect type in argument 2 (different signedness)
kernel/kgdb.c:1127:28: expected long *long_val
kernel/kgdb.c:1127:28: got unsigned long *<noident>
kernel/kgdb.c:1132:25: warning: incorrect type in argument 2 (different signedness)
kernel/kgdb.c:1132:25: expected long *long_val
kernel/kgdb.c:1132:25: got unsigned long *<noident>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The single step test is not terribly costly and it should be able to
pass at 1000 loops successfully in under 1 second. A non-kgdb timing
regression was found using this test, but it did not occur frequently
because by default the test was only executed a single time.
This patch changes the default for the single step test to 1000
iterations and allows for individual configuration of the single step
test to further exercise the kgdb subsystem when needed.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Shadowed variable and integer as NULL pointer fixes:
drivers/misc/kgdbts.c:877:6: warning: symbol 'sys_open_test' shadows an earlier one
drivers/misc/kgdbts.c:537:27: originally declared here
drivers/misc/kgdbts.c:378:22: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:386:22: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:468:30: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:472:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:502:30: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:506:30: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:509:30: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:523:20: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:527:20: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:530:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:541:21: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:545:21: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:548:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:559:30: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:563:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:573:16: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:574:19: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:578:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:588:16: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:589:19: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:593:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:602:16: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:604:15: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:925:3: warning: Using plain integer as NULL pointer
drivers/misc/kgdbts.c:938:3: warning: Using plain integer as NULL pointer
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Two minor fixes to the kgdb documentation.
Signed-off-by: Grzegorz Chwesewicz, Chilan <grzegorz.chwesewicz@chilan.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
S3C2410 i2s driver currently manages only i2s protocol (and not left
justified one) and slave mode.
With this small patch, other modes are possible.
Signed-off-by: Davide Rizzo <davide@elpa.it>
Acked-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
S3C2410 pcm doesn't work.
s3c2410_dma_request() now returns the channel number and not 0 if OK.
Signed-off-by: Davide Rizzo <davide@elpa.it>
Acked-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
On boards with VT1617A codec, the sound disappears suddenly.
This looks like a problem with HPE-bit control that is supposed to be
set in patch_vt1617a(). However, on such problematic hardwares, the
bit is actually reset mysteriously.
The patch adds a workaround for the wrong quirk.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
FM801-tea575x tuner has a reverse selection to V4L1 and this causes
nasty dependency problems.
The patch simplifies the dependency with a normal
"depends on VIDEO_V4L1". This decreases the usability but fixes bugs,
yeah. If any better feature like "requires" is introduced to kbuild
in future, we'll be able to switch it...
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/drivers/pcsp/pcsp.c: In function 'pcsp_suspend':
sound/drivers/pcsp/pcsp.c:201: error: implicit declaration of function 'snd_pcm_suspend_all'
Signed-off-by: Johann Felix Soden <johfel@users.sourceforge.net>
CC: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
x86.git testing found this build bug on v2.6.26-rc1:
ERROR: "pnp_get_resource" [drivers/net/irda/smsc-ircc2.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
the driver did not anticipate the case of !CONFIG_PNP which is rare but
still possible. Instead of restricting the driver to PNP-only in the
Kconfig space, add the (trivial) dummy struct pnp_driver - this is that
other drivers use in the !PNP case too.
The driver itself can in theory be initialized on !PNP too in certain
cases, via smsc_ircc_legacy_probe().
Patch only minimally build tested, i dont have this hardware.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
x86.git testing found the following build failure in latest -git:
drivers/built-in.o: In function `nsc_ircc_pnp_probe':
nsc-ircc.c:(.text+0xdf1b6): undefined reference to `pnp_get_resource'
nsc-ircc.c:(.text+0xdf1d4): undefined reference to `pnp_get_resource'
nsc-ircc.c:(.text+0xdf1ee): undefined reference to `pnp_get_resource'
nsc-ircc.c:(.text+0xdf237): undefined reference to `pnp_get_resource'
nsc-ircc.c:(.text+0xdf24c): undefined reference to `pnp_get_resource'
drivers/built-in.o:nsc-ircc.c:(.text+0xdf266): more undefined references to `pnp_get_resource' follow
make: *** [.tmp_vmlinux1] Error 1
triggered via this config:
http://redhat.com/~mingo/misc/config-Sat_May__3_20_53_13_CEST_2008.bad
while generally most users will have PNP enabled, drivers can support
non-PNP build mode too - and most drivers implement it. That is typically
done by providing a dummy pnp_driver structure that will not probe anything.
The fallback routines in the driver will handle this dumber mode of
operation too.
This patch implements that. I have not tested whether this actually
works on real hardware so take care. It does resolve the build bug.
[ Another solution that is used by a few drivers is to exclude the driver
in the Kconfig if PNP is disabled, via "depends on PNP", but this would
limit the availability of the driver needlessly. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using the variable name 'dev_name' in the top-level namespace is a bad
idea.
This conflicts with linux/device.h's inline function of the same name.
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert to netlink helpers by using netlink policy validation.
As a side effect fixes a leak.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Simply replace proc_create and further data assigned with proc_create_data.
No need to check for data!=NULL after that.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
