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>
* '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
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>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
kconfig-language.txt: remove bogus hint
kconfig: fix MAC OS X warnings in menuconfig
modpost: i2c aliases need no trailing wildcard
* 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
x86: KVM geust: make setup_secondary_clock definition dependent on local apic
KVM: MMU: Allow more than PAGES_PER_HPAGE write protections per large page
KVM: avoid fx_init() schedule in atomic
KVM: Avoid spurious execeptions after setting registers
KVM: PIT: support mode 4
KVM: x86 emulator: disable writeback on lmsw
KVM: ppc: deliver INTERRUPT_FP_UNAVAIL to the guest
KVM: ppc: Handle guest idle by emulating MSR[WE] writes
KVM: x86: task switch: fix wrong bit setting for the busy flag
KVM: VMX: Enable EPT feature for KVM
KVM: VMX: Prepare an identity page table for EPT in real mode
KVM: Export necessary function for EPT
KVM: MMU: Remove #ifdef CONFIG_X86_64 to support 4 level EPT
KVM: MMU: Add EPT support
KVM: Add kvm_x86_ops get_tdp_level()
KVM: MMU: Move some definitions to a header file
KVM: VMX: EPT Feature Detection
x86.git testing found the following build failure on v2.6.26-rc1:
In file included from include/linux/kobject.h:22,
from include/linux/module.h:17,
from include/linux/crypto.h:22,
from arch/x86/kernel/asm-offsets_32.c:8,
from arch/x86/kernel/asm-offsets.c:3:
include/linux/sysfs.h:201: error: redefinition of 'sysfs_update_group'
include/linux/sysfs.h:195: error: previous definition of 'sysfs_update_group' was here
make[1]: *** [arch/x86/kernel/asm-offsets.s] Error 1
make: *** [prepare0] Error 2
with the following config:
http://redhat.com/~mingo/misc/config-Sun_May__4_07_09_30_CEST_2008.bad
the reason for the build failure is the duplicate definition of the
sysfs_update_group() inline function in include/linux/sysfs.h.
The duplication was a merge error: it was added via -mm by commit
v2.6.25-7262-g2850699, "sysfs: sysfs_update_group stub for
CONFIG_SYSFS=n" a day before v2.6.26-rc1, but a day before that the same
commit was already merged upstream via the sysfs tree, with commit
v2.6.25-7211-g1cbfb7a.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel module loader used to be much too happy to allow loading of
modules for the wrong kernel version by default. For example, if you
had MODVERSIONS enabled, but tried to load a module with no version
info, it would happily load it and taint the kernel - whether it was
likely to actually work or not!
Generally, such forced module loading should be considered a really
really bad idea, so make it conditional on a new config option
(MODULE_FORCE_LOAD), and make it default to off.
If somebody really wants to force module loads, that's their problem,
but we should not encourage it. Especially as it happened to me by
mistake (ie regular unversioned Fedora modules getting loaded) causing
lots of strange behavior.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the following compile error caused by
commit 23cf11ddb5
(mips: types: use <asm-generic/int-*.h> for the mips architecture):
<-- snip -->
...
CC kernel/bounds.s
In file included from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/types.h:12,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/page-flags.h:8,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/kernel/bounds.c:9:
include2/asm/types.h:56:2: error: #endif without #if
make[2]: *** [kernel/bounds.s] Error 1
<-- snip -->
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This patch fixes the following compile error on alpha caused by
commit 3726c23df8
(alpha: types: use <asm-generic/int-*.h> for the alpha architecture):
<-- snip -->
...
CC arch/alpha/kernel/asm-offsets.s
In file included from include2/asm/topology.h:6,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/topology.h:34,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/mmzone.h:683,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/gfp.h:4,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/slab.h:12,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/percpu.h:5,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/rcupdate.h:39,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/pid.h:4,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/sched.h:74,
from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/alpha/kernel/asm-offsets.c:9:
include2/asm/machvec.h:44: error: expected declaration specifiers or '...' before 'dma_addr_t'
include2/asm/machvec.h:44: error: expected declaration specifiers or '...' before 'dma_addr_t'
In file included from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/alpha/kernel/asm-offsets.c:12:
include2/asm/io.h:94: warning: type defaults to 'int' in declaration of 'dma_addr_t'
include2/asm/io.h:94: warning: variable 'dma_addr_t' declared 'inline'
include2/asm/io.h:94: error: expected ',' or ';' before 'isa_page_to_bus'
make[2]: *** [arch/alpha/kernel/asm-offsets.s] Error 1
<-- snip -->
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
For the use case the hint describe a simple dependency is
enough.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Fix x86 setup printk format warming:
next-20080430/arch/x86/kernel/setup.c:172: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'ssize_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the missing MODULE_LICENSE("GPL").
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
commit 8b664aa66e (x86, boot: add linked
list of struct setup_data) put a new struct in bootparam.h, but didn't
use the userspace-safe types.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Huang Ying <ying.huang@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
