kernel-ark/kernel
Peter Zijlstra 79b3feffb1 sched: fix regression with sched yield
Balbir Singh reported:

> 1:mon> t
> [c0000000e7677da0] c000000000067de0 .sys_sched_yield+0x6c/0xbc
> [c0000000e7677e30] c000000000008748 syscall_exit+0x0/0x40
> --- Exception: c01 (System Call) at 00000400001d09e4
> SP (4000664cb10) is in userspace
> 1:mon> r
> cpu 0x1: Vector: 300 (Data Access) at [c0000000e7677aa0]
>     pc: c000000000068e50: .yield_task_fair+0x94/0xc4
>     lr: c000000000067de0: .sys_sched_yield+0x6c/0xbc

the check that should have avoided that is:

        /*
         * Are we the only task in the tree?
         */
        if (unlikely(rq->load.weight == curr->se.load.weight))
                return;

But I guess that overlooks rt tasks, they also increase the load.
So I guess something like this ought to fix it..

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
..
irq genirq: do not leave interupts enabled on free_irq 2008-02-19 10:43:58 +01:00
power Merge branches 'release' and 'doc' into release 2008-03-13 01:59:53 -04:00
time Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt 2008-04-18 08:37:41 -07:00
.gitignore Update kernel/.gitignore with new auto-generated files 2008-02-09 23:27:01 -08:00
acct.c bsd_acct: using task_struct->tgid is not right in pid-namespaces 2008-03-24 19:22:20 -07:00
audit_tree.c Introduce path_put() 2008-02-14 21:13:33 -08:00
audit.c Audit: internally use the new LSM audit hooks 2008-04-19 09:52:37 +10:00
audit.h SELinux: use new audit hooks, remove redundant exports 2008-04-19 09:53:46 +10:00
auditfilter.c Audit: Final renamings and cleanup 2008-04-19 09:59:43 +10:00
auditsc.c Audit: Final renamings and cleanup 2008-04-19 09:59:43 +10:00
backtracetest.c x86: add a simple backtrace test module 2008-01-30 13:33:08 +01:00
capability.c Add 64-bit capability support to the kernel 2008-02-05 09:44:20 -08:00
cgroup_debug.c Task Control Groups: simple task cgroup debug info subsystem 2007-10-19 11:53:36 -07:00
cgroup.c cgroup: fix a race condition in manipulating tsk->cg_list 2008-04-18 08:17:57 -07:00
compat.c hrtimer: use nanosleep specific restart_block fields 2008-04-17 12:22:30 +02:00
configs.c use simple_read_from_buffer in kernel/ 2007-05-09 12:30:49 -07:00
cpu.c cpu: fix section mismatch warnings for enable_nonboot_cpus 2008-02-08 09:22:41 -08:00
cpuset.c cpusets: fix obsolete comment 2008-03-05 17:53:33 -08:00
delayacct.c Add scaled time to taskstats based process accounting 2007-10-18 14:37:28 -07:00
dma.c whitespace fixes: DMA channel allocator 2007-10-18 14:37:24 -07:00
exec_domain.c whitespace fixes: execution domains 2007-10-18 14:37:26 -07:00
exit.c asmlinkage_protect replaces prevent_tail_call 2008-04-10 17:28:26 -07:00
extable.c module: Don't report discarded init pages as kernel text. 2008-01-29 17:13:18 +11:00
fork.c memcgroup: fix spurious EBUSY on memory cgroup removal 2008-03-28 14:45:21 -07:00
futex_compat.c futex_compat __user annotation 2008-03-30 14:18:41 -07:00
futex.c NULL noise: fs/*, mm/*, kernel/* 2008-03-30 14:18:41 -07:00
hrtimer.c hrtimers: simplify lockdep handling 2008-04-17 12:22:31 +02:00
itimer.c ITIMER_REAL: convert to use struct pid 2008-02-08 09:22:29 -08:00
kallsyms.c remove support for un-needed _extratext section 2008-02-06 10:41:01 -08:00
Kconfig.hz sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
Kconfig.preempt rcu: move PREEMPT_RCU config option back under PREEMPT 2008-03-10 18:01:20 -07:00
kexec.c vmcoreinfo: add "VMCOREINFO_" to all the call for vmcoreinfo_append_str() 2008-02-07 08:42:25 -08:00
kfifo.c is_power_of_2: kernel/kfifo.c 2007-07-16 09:05:50 -07:00
kgdb.c kgdb: always use icache flush for sw breakpoints 2008-04-17 20:05:43 +02:00
kmod.c Dont touch fs_struct in usermodehelper 2008-02-14 21:13:32 -08:00
kprobes.c kprobes: fix a null pointer bug in register_kretprobe() 2008-03-04 16:35:19 -08:00
ksysfs.c Kobject: convert remaining kobject_unregister() to kobject_put() 2008-01-24 20:40:40 -08:00
kthread.c sched: fix, always create kernel threads with normal priority 2008-01-25 21:08:33 +01:00
latencytop.c latencytop: optimize LT_BACKTRACEDEPTH loops a bit 2008-04-19 19:44:57 +02:00
lockdep_internals.h
lockdep_proc.c lockdep: Avoid /proc/lockdep & lock_stat infinite output 2007-10-11 22:11:11 +02:00
lockdep.c Subject: lockdep: include all lock classes in all_lock_classes 2008-02-25 23:03:02 +01:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb 2008-04-18 08:37:01 -07:00
marker.c markers: use synchronize_sched() 2008-04-02 15:28:19 -07:00
module.c modules: warn about suspicious return values from module's ->init() hook 2008-03-10 18:01:20 -07:00
mutex-debug.c kernel: remove fastcall in kernel/* 2008-02-08 09:22:31 -08:00
mutex-debug.h
mutex.c kernel: remove fastcall in kernel/* 2008-02-08 09:22:31 -08:00
mutex.h
notifier.c kernel/notifier.c should #include <linux/reboot.h> 2008-02-06 10:41:02 -08:00
ns_cgroup.c cgroups: implement namespace tracking subsystem 2007-10-19 11:53:37 -07:00
nsproxy.c namespaces: move the IPC namespace under IPC_NS option 2008-02-08 09:22:23 -08:00
panic.c ACPI: Taint kernel on ACPI table override (format corrected) 2008-02-06 22:07:51 -05:00
params.c Add new string functions strict_strto* and convert kernel params to use them 2008-02-08 09:22:41 -08:00
pid_namespace.c namespaces: cleanup the code managed with PID_NS option 2008-02-08 09:22:23 -08:00
pid.c kernel: remove fastcall in kernel/* 2008-02-08 09:22:31 -08:00
pm_qos_params.c pm qos infrastructure and interface 2008-02-05 09:44:22 -08:00
posix-cpu-timers.c posix-timers: fix shadowed variables 2008-04-17 12:22:30 +02:00
posix-timers.c hrtimer: check relative timeouts for overflow 2008-02-14 22:08:30 +01:00
printk.c Fix locking bug in "acquire_console_semaphore_for_printk()" 2008-04-15 13:09:54 -07:00
profile.c Nuke a duplicate include from profile.c 2008-02-08 09:22:34 -08:00
ptrace.c ptrace_check_attach: remove unneeded ->signal != NULL check 2008-02-08 09:22:26 -08:00
rcuclassic.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
rcupdate.c rcupdate: fix comment 2008-02-13 16:21:18 -08:00
rcupreempt_trace.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
rcupreempt.c rcupreempt: remove never-migrates assumption from rcu_process_callbacks() 2008-02-29 20:21:13 +01:00
rcutorture.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
relay.c relay: set an spd_release() hook for splice 2008-03-26 12:04:09 +01:00
res_counter.c Memory Resource Controller use strstrip while parsing arguments 2008-03-04 16:35:09 -08:00
resource.c [POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc 2008-02-08 19:52:48 +11:00
rtmutex_common.h Don't operate with pid_t in rtmutex tester 2008-02-08 09:22:41 -08:00
rtmutex-debug.c Don't operate with pid_t in rtmutex tester 2008-02-08 09:22:41 -08:00
rtmutex-debug.h
rtmutex-tester.c Driver core: change sysdev classes to use dynamic kobject names 2008-01-24 20:40:40 -08:00
rtmutex.c hrtimer: more hrtimer_init_sleeper() fallout. 2008-02-13 15:45:36 +01:00
rtmutex.h
rwsem.c sched: mark rwsem functions as __sched for wchan/profiling 2007-12-18 15:21:13 +01:00
sched_debug.c sched: remove sysctl_sched_batch_wakeup_granularity 2008-04-19 19:44:57 +02:00
sched_fair.c sched: fix regression with sched yield 2008-04-19 19:44:57 +02:00
sched_idletask.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
sched_rt.c sched: balance RT task resched only on runqueue 2008-03-07 16:43:00 +01:00
sched_stats.h sched: clean up kernel/sched_stat.h 2007-11-28 15:52:56 +01:00
sched.c sched: remove sysctl_sched_batch_wakeup_granularity 2008-04-19 19:44:57 +02:00
seccomp.c make seccomp zerocost in schedule 2007-07-16 09:05:50 -07:00
semaphore.c Improve semaphore documentation 2008-04-17 10:43:01 -04:00
signal.c ptrace_signal subroutine 2008-04-18 08:17:57 -07:00
softirq.c rcu: add support for dynamic ticks and preempt rcu 2008-02-29 18:46:50 +01:00
softlockup.c softlockup: fix task state setting 2008-02-29 18:46:53 +01:00
spinlock.c spinlock: lockbreak cleanup 2008-01-30 13:31:20 +01:00
srcu.c make srcu_readers_active() static 2008-02-06 10:41:02 -08:00
stacktrace.c
stop_machine.c stopmachine: semaphore to mutex 2008-02-06 10:41:08 -08:00
sys_ni.c timerfd: new timerfd API 2008-02-05 09:44:07 -08:00
sys.c Pidns: make full use of xxx_vnr() calls 2008-02-08 09:22:29 -08:00
sysctl_check.c constify tables in kernel/sysctl_check.c 2008-02-08 09:22:31 -08:00
sysctl.c sched: remove sysctl_sched_batch_wakeup_granularity 2008-04-19 19:44:57 +02:00
taskstats.c kernel/taskstats.c: fix bogus nlmsg_free() 2007-11-14 18:45:44 -08:00
test_kprobes.c kprobes: kretprobe user entry-handler 2008-02-06 10:41:11 -08:00
time.c avoid overflows in kernel/time.c 2008-02-08 09:22:39 -08:00
timeconst.pl timeconst.pl: correct reversal of USEC_TO_HZ and HZ_TO_USEC 2008-02-12 14:29:26 -08:00
timer.c timers: simplify lockdep handling 2008-04-17 12:22:31 +02:00
tsacct.c Add scaled time to taskstats based process accounting 2007-10-18 14:37:28 -07:00
uid16.c asmlinkage_protect replaces prevent_tail_call 2008-04-10 17:28:26 -07:00
user_namespace.c namespaces: cleanup the code managed with the USER_NS option 2008-02-08 09:22:23 -08:00
user.c sched: rt-group: make rt groups scheduling configurable 2008-02-13 15:45:40 +01:00
utsname_sysctl.c Isolate the UTS namespace's domainname and hostname back 2007-11-29 09:24:53 -08:00
utsname.c Fix UTS corruption during clone(CLONE_NEWUTS) 2007-09-19 11:24:17 -07:00
wait.c kernel: remove fastcall in kernel/* 2008-02-08 09:22:31 -08:00
workqueue.c timer_list: add annotations to workqueue.c 2008-04-17 12:22:30 +02:00