kernel_optimize_test/kernel
Miao Xie cb4ad1ffc7 sched: fair-group: fix a Div0 error of the fair group scheduler
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>
2008-05-05 23:56:18 +02:00
..
irq genirq: reenable a nobody cared disabled irq when a new driver arrives 2008-05-02 13:40:34 +02:00
power Merge branches 'release', 'acpica', 'bugzilla-10224', 'bugzilla-9772', 'bugzilla-9916', 'ec', 'eeepc', 'idle', 'misc', 'pm-legacy', 'sysfs-links-2.6.26', 'thermal', 'thinkpad' and 'video' into release 2008-04-30 13:58:00 -04:00
time clocksource: allow read access to available/current_clocksource 2008-05-03 18:11:48 +02:00
.gitignore
acct.c
audit_tree.c
audit.c [patch 2/2] Use find_task_by_vpid in audit code 2008-04-28 06:28:30 -04:00
audit.h [PATCH 1/2] audit: move extern declarations to audit.h 2008-04-28 06:28:04 -04:00
auditfilter.c Merge branch 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current 2008-04-29 11:41:22 -07:00
auditsc.c [PATCH] new predicate - AUDIT_FILETYPE 2008-04-28 06:28:37 -04:00
backtracetest.c
bounds.c Add kbuild.h that contains common definitions for kbuild users 2008-04-29 08:06:29 -07:00
capability.c
cgroup_debug.c CGroup API files: move "releasable" to cgroup_debug subsystem 2008-04-29 08:06:09 -07:00
cgroup.c mm: bdi: add separate writeback accounting capability 2008-04-30 08:29:50 -07:00
compat.c ntp: support for TAI 2008-05-01 08:03:59 -07:00
configs.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
cpu.c kernel: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
cpuset.c Cpuset hardwall flag: add a mem_hardwall flag to cpusets 2008-04-29 08:06:11 -07:00
delayacct.c
dma.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
exec_domain.c
exit.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
extable.c
fork.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
futex_compat.c
futex.c Removal of FUTEX_FD 2008-05-05 08:18:45 -07:00
hrtimer.c hrtimer: remove duplicate helper function 2008-05-03 18:11:48 +02:00
itimer.c
kallsyms.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
Kconfig.hz
Kconfig.preempt
kexec.c kexec: make extended crashkernel= syntax less confusing 2008-05-01 08:04:00 -07:00
kfifo.c
kgdb.c kgdb: fix signedness mixmatches, add statics, add declaration to header 2008-05-05 07:13:21 -05:00
kmod.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
kprobes.c kprobes: add (un)register_jprobes for batch registration 2008-04-28 08:58:32 -07:00
ksysfs.c
kthread.c Deprecate find_task_by_pid() 2008-04-30 08:29:48 -07:00
latencytop.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
lockdep_internals.h
lockdep_proc.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
lockdep.c
Makefile sysctl: allow embedded targets to disable sysctl_check.c 2008-04-29 08:06:22 -07:00
marker.c make marker_debug static 2008-04-30 08:29:49 -07:00
module.c Make forced module loading optional 2008-05-04 17:04:16 -07:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c ipc: re-enable msgmni automatic recomputing msgmni if set to negative 2008-04-29 08:06:13 -07:00
ns_cgroup.c cgroups: kernel/ns_cgroup.c should #include <linux/nsproxy.h> 2008-04-29 08:06:07 -07:00
nsproxy.c ipc: sysvsem: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC) 2008-04-29 08:06:14 -07:00
panic.c Taint kernel after WARN_ON(condition) 2008-04-29 08:05:59 -07:00
params.c
pid_namespace.c pidns: make pid->level and pid_ns->level unsigned 2008-04-30 08:29:49 -07:00
pid.c pids: introduce change_pid() helper 2008-04-30 08:29:48 -07:00
pm_qos_params.c
posix-cpu-timers.c remove div_long_long_rem 2008-05-01 08:03:58 -07:00
posix-timers.c signals: join send_sigqueue() with send_group_sigqueue() 2008-04-30 08:29:36 -07:00
printk.c printk: don't read beyond string arguments' terminating zero 2008-04-30 08:29:52 -07:00
profile.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
ptrace.c make generic sys_ptrace unconditional 2008-05-01 10:21:54 -07:00
rcuclassic.c
rcupdate.c
rcupreempt_trace.c
rcupreempt.c
rcutorture.c kernel: explicitly include required header files under kernel/ 2008-04-29 08:06:04 -07:00
relay.c Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2008-04-29 08:18:03 -07:00
res_counter.c memcgroup: add the max_usage member on the res_counter 2008-04-29 08:06:10 -07:00
resource.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_debug.c rename div64_64 to div64_u64 2008-05-01 08:03:58 -07:00
sched_fair.c sched: fix debugging 2008-05-05 23:56:18 +02:00
sched_features.h sched: /debug/sched_features 2008-04-19 19:45:00 +02:00
sched_idletask.c sched: make rt_sched_class, idle_sched_class static 2008-05-05 23:56:17 +02:00
sched_rt.c sched: fix RT task-wakeup logic 2008-05-05 23:56:18 +02:00
sched_stats.h cpumask: use new cpus_scnprintf function 2008-04-19 19:44:59 +02:00
sched.c sched: fair-group: fix a Div0 error of the fair group scheduler 2008-05-05 23:56:18 +02:00
seccomp.c
semaphore.c
signal.c signals: add set_restore_sigmask 2008-04-30 08:29:37 -07:00
softirq.c Fix cpu hotplug problem in softirq code 2008-05-01 08:03:58 -07:00
softlockup.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial 2008-04-21 16:36:46 -07:00
sys_ni.c
sys.c pids: sys_getpgid: fix unsafe *pid usage, s/tasklist/rcu/ 2008-04-30 08:29:49 -07:00
sysctl_check.c
sysctl.c sysctl: add the ->permissions callback on the ctl_table_root 2008-04-29 08:06:23 -07:00
taskstats.c Use find_task_by_vpid in taskstats 2008-04-30 08:29:48 -07:00
test_kprobes.c
time.c Make constants in kernel/timeconst.h fixed 64 bits 2008-05-02 16:18:42 -07:00
timeconst.pl Make constants in kernel/timeconst.h fixed 64 bits 2008-05-02 16:18:42 -07:00
timer.c debugobjects: add timer specific object debugging code 2008-04-30 08:29:53 -07:00
tsacct.c
uid16.c
user_namespace.c eCryptfs: make key module subsystem respect namespaces 2008-04-29 08:06:07 -07:00
user.c alloc_uid: cleanup 2008-04-30 08:29:53 -07:00
utsname_sysctl.c
utsname.c kernel: explicitly include required header files under kernel/ 2008-04-29 08:06:04 -07:00
wait.c
workqueue.c workqueue: remove redundant function invocation 2008-05-01 08:04:02 -07:00