kernel_optimize_test/kernel
Steven Rostedt d7240b9880 generic-ipi: use per cpu data for single cpu ipi calls
The smp_call_function can be passed a wait parameter telling it to
wait for all the functions running on other CPUs to complete before
returning, or to return without waiting. Unfortunately, this is
currently just a suggestion and not manditory. That is, the
smp_call_function can decide not to return and wait instead.

The reason for this is because it uses kmalloc to allocate storage
to send to the called CPU and that CPU will free it when it is done.
But if we fail to allocate the storage, the stack is used instead.
This means we must wait for the called CPU to finish before
continuing.

Unfortunatly, some callers do no abide by this hint and act as if
the non-wait option is mandatory. The MTRR code for instance will
deadlock if the smp_call_function is set to wait. This is because
the smp_call_function will wait for the other CPUs to finish their
called functions, but those functions are waiting on the caller to
continue.

This patch changes the generic smp_call_function code to use per cpu
variables if the allocation of the data fails for a single CPU call. The
smp_call_function_many will fall back to the smp_call_function_single
if it fails its alloc. The smp_call_function_single is modified
to not force the wait state.

Since we now are using a single data per cpu we must synchronize the
callers to prevent a second caller modifying the data before the
first called IPI functions complete. To do so, I added a flag to
the call_single_data called CSD_FLAG_LOCK. When the single CPU is
called (which can be called when a many call fails an alloc), we
set the LOCK bit on this per cpu data. When the caller finishes
it clears the LOCK bit.

The caller must wait till the LOCK bit is cleared before setting
it. When it is cleared, there is no IPI function using it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-30 18:31:08 +01:00
..
irq async: Asynchronous function calls to speed up kernel boot 2009-01-07 08:45:46 -08:00
power PM: Fix freezer compilation if PM_SLEEP is unset 2009-01-16 14:32:17 -05:00
time time-sched.c: tick_nohz_update_jiffies should be static 2009-01-15 12:06:56 +01:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile 2009-01-09 12:43:06 -08:00
.gitignore
acct.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
async.c async: fix __lowest_in_progress() 2009-01-12 16:39:58 -08:00
audit_tree.c audit: validate comparison operations, store them in sane form 2009-01-04 15:14:42 -05:00
audit.c [PATCH] fix broken timestamps in AVC generated by kernel threads 2008-12-09 02:27:41 -05:00
audit.h fixing audit rule ordering mess, part 1 2009-01-04 15:14:41 -05:00
auditfilter.c audit: validate comparison operations, store them in sane form 2009-01-04 15:14:42 -05:00
auditsc.c make sure that filterkey of task,always rules is reported 2009-01-04 15:14:42 -05:00
backtracetest.c
bounds.c
capability.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
cgroup_debug.c cgroups: fix probable race with put_css_set[_taskexit] and find_css_set 2008-10-20 08:52:38 -07:00
cgroup_freezer.c freezer_cg: disable writing freezer.state of root cgroup 2008-11-12 17:17:16 -08:00
cgroup.c cgroups: add css_tryget() 2009-01-08 08:31:10 -08:00
compat.c Allow times and time system calls to return small negative values 2009-01-06 15:59:13 -08:00
configs.c kernel/configs.c: remove useless comments 2008-10-20 08:52:34 -07:00
cpu.c stop_machine/cpu hotplug: fix disable_nonboot_cpus 2009-01-07 11:36:14 -08:00
cpuset.c cgroups: consolidate cgroup documents 2009-01-15 16:39:37 -08:00
cred-internals.h CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2009-01-09 13:59:25 -08:00
delayacct.c schedstat: consolidate per-task cpu runtime stats 2008-12-18 13:54:01 +01:00
dma-coherent.c dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy. 2009-01-21 18:51:53 +09:00
dma.c kernel/dma.c: remove a CVS keyword 2008-10-16 11:21:30 -07:00
exec_domain.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
exit.c [CVE-2009-0029] System call wrappers part 08 2009-01-14 14:15:21 +01:00
extable.c Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-30 16:10:19 -08:00
fork.c Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-26 09:47:43 -08:00
freezer.c freezer_cg: use thaw_process() in unfreeze_cgroup() 2008-10-30 11:38:45 -07:00
futex_compat.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
futex.c [CVE-2009-0029] System call wrappers part 31 2009-01-14 14:15:31 +01:00
hrtimer.c Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-26 09:47:43 -08:00
itimer.c [CVE-2009-0029] System call wrappers part 05 2009-01-14 14:15:20 +01:00
kallsyms.c allow stripping of generated symbols under CONFIG_KALLSYMS_ALL 2008-12-19 22:47:10 +01:00
Kconfig.freezer container freezer: implement freezer cgroup subsystem 2008-10-20 08:52:34 -07:00
Kconfig.hz sched: fix SCHED_HRTICK dependency 2008-07-28 14:37:38 +02:00
Kconfig.preempt rcu: provide RCU options on non-preempt architectures too 2008-12-25 09:31:28 +01:00
kexec.c [CVE-2009-0029] System call wrappers part 07 2009-01-14 14:15:20 +01:00
kfifo.c
kgdb.c kgdb: call touch_softlockup_watchdog on resume 2008-10-06 13:50:59 -05:00
kmod.c kmod: fix varargs kernel-doc 2009-01-06 15:59:27 -08:00
kprobes.c kprobes: check CONFIG_FREEZER instead of CONFIG_PM 2009-01-16 14:32:17 -05:00
ksysfs.c kernel/ksysfs.c:fix dependence on CONFIG_NET 2009-01-06 10:44:31 -08:00
kthread.c tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() 2008-11-16 09:01:36 +01:00
latencytop.c KSYM_SYMBOL_LEN fixes 2008-12-10 08:01:54 -08:00
lockdep_internals.h lockdep: build fix 2008-08-13 12:55:10 +02:00
lockdep_proc.c lockstat: contend with points 2008-10-20 15:43:10 +02:00
lockdep.c Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-30 16:10:19 -08:00
Makefile kernel/up.c: omit it if SMP=y, USE_GENERIC_SMP_HELPERS=n 2009-01-14 09:42:11 -08:00
marker.c markers/tracpoints: fix non-modular build 2008-11-16 09:52:03 +01:00
module.c [CVE-2009-0029] System call wrappers part 08 2009-01-14 14:15:21 +01:00
mutex-debug.c
mutex-debug.h
mutex.c mutex: __used is needed for function referenced only from inline asm 2008-11-24 10:00:28 +01:00
mutex.h
notifier.c Merge commit 'v2.6.28-rc6' into core/debug 2008-11-26 08:22:50 +01:00
ns_cgroup.c ns_cgroup: remove unused spinlock 2009-01-08 08:31:02 -08:00
nsproxy.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
panic.c oops: increment the oops UUID every time we oops 2009-01-06 15:59:12 -08:00
params.c Fix compile warning in kernel/params.c 2008-10-23 12:09:00 -07:00
pid_namespace.c pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits 2008-09-02 19:21:38 -07:00
pid.c pid: generalize task_active_pid_ns 2009-01-08 08:31:12 -08:00
pm_qos_params.c pm_qos_requirement might sleep 2008-09-02 19:21:40 -07:00
posix-cpu-timers.c itimers: remove the per-cpu-ish-ness 2009-01-07 18:52:44 +01:00
posix-timers.c [CVE-2009-0029] System call wrappers part 05 2009-01-14 14:15:20 +01:00
printk.c [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
profile.c profile: don't include <asm/ptrace.h> twice. 2009-01-06 15:59:14 -08:00
ptrace.c [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
rcuclassic.c rcu: add __cpuinit to rcu_init_percpu_data() 2009-01-14 11:26:40 +01:00
rcupdate.c rcu: eliminate synchronize_rcu_xxx macro 2009-01-05 10:18:08 +01:00
rcupreempt_trace.c "Tree RCU": scalable classic RCU implementation 2008-12-18 21:56:04 +01:00
rcupreempt.c rcu: eliminate synchronize_rcu_xxx macro 2009-01-05 10:18:08 +01:00
rcutorture.c rcu: fix bug in rcutorture system-shutdown code 2009-01-07 23:36:25 +01:00
rcutree_trace.c "Tree RCU": scalable classic RCU implementation 2008-12-18 21:56:04 +01:00
rcutree.c rcu: add __cpuinit to rcu_init_percpu_data() 2009-01-14 11:26:40 +01:00
relay.c relay: fix lock imbalance in relay_late_setup_files 2009-01-18 20:29:35 +01:00
res_counter.c memcg: memory cgroup resource counters for hierarchy 2009-01-08 08:31:05 -08:00
resource.c resources: fix parameter name and kernel-doc 2009-01-15 16:39:38 -08:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c sysdev: Pass the attribute to the low level sysdev show/store function 2008-07-21 21:55:02 -07:00
rtmutex.c hrtimer: convert kernel/* to the new hrtimer apis 2008-09-05 21:35:13 -07:00
rtmutex.h
rwsem.c
sched_clock.c sched_clock: prevent scd->clock from moving backwards, take #2 2008-12-31 09:53:21 +01:00
sched_cpupri.c sched: fix section mismatch 2009-01-06 11:07:15 +01:00
sched_cpupri.h sched: convert struct cpupri_vec cpumask_var_t. 2008-11-24 17:52:22 +01:00
sched_debug.c sched: partly revert "sched debug: remove NULL checking in print_cfs_rt_rq()" 2009-01-11 02:40:32 +01:00
sched_fair.c sched: sched_slice() fixlet 2009-01-15 21:07:57 +01:00
sched_features.h sched: backward looking buddy 2008-11-05 10:30:14 +01:00
sched_idletask.c sched: add CONFIG_SMP consistency 2008-10-22 10:01:52 +02:00
sched_rt.c sched: put back some stack hog changes that were undone in kernel/sched.c 2009-01-03 19:00:09 +01:00
sched_stats.h itimers: remove the per-cpu-ish-ness 2009-01-07 18:52:44 +01:00
sched.c Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-15 16:55:00 -08:00
seccomp.c
semaphore.c semaphore: __down_common: use signal_pending_state() 2008-08-05 14:33:47 -07:00
signal.c signals, debug: fix BUG: using smp_processor_id() in preemptible code in print_fatal_signal() 2009-01-27 00:36:19 +01:00
smp.c generic-ipi: use per cpu data for single cpu ipi calls 2009-01-30 18:31:08 +01:00
softirq.c Merge branch 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-03 12:04:39 -08:00
softlockup.c softlock: fix false panic which can occur if softlockup_thresh is reduced 2009-01-14 11:48:07 +01:00
spinlock.c lockdep: spin_lock_nest_lock(), checkpatch fixes 2008-08-13 13:56:51 +02:00
srcu.c
stacktrace.c stacktrace: provide save_stack_trace_tsk() weak alias 2008-12-25 11:44:43 +01:00
stop_machine.c stop_machine: introduce stop_machine_create/destroy. 2009-01-05 08:40:14 +10:30
sys_ni.c [CVE-2009-0029] Make sys_syslog a conditional system call 2009-01-14 14:15:16 +01:00
sys.c [CVE-2009-0029] System call wrappers part 31 2009-01-14 14:15:31 +01:00
sysctl_check.c [XFS] remove restricted chown parameter from xfs linux 2008-10-30 18:30:09 +11:00
sysctl.c Merge branch 'core/debugobjects' into core/urgent 2009-01-22 10:03:02 +01:00
taskstats.c cpumask: convert rest of files in kernel/ 2009-01-01 10:12:28 +10:30
test_kprobes.c kprobes: add tests for register_kprobes 2009-01-06 15:59:20 -08:00
time.c [CVE-2009-0029] System call wrappers part 01 2009-01-14 14:15:18 +01:00
timeconst.pl
timer.c [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
tracepoint.c markers/tracpoints: fix non-modular build 2008-11-16 09:52:03 +01:00
tsacct.c mm: introduce get_mm_hiwater_xxx(), fix taskstats->hiwater_xxx accounting 2009-01-06 15:59:09 -08:00
uid16.c [CVE-2009-0029] System call wrappers part 19 2009-01-14 14:15:26 +01:00
up.c smp_call_function_single(): be slightly less stupid, fix #2 2009-01-12 16:04:37 +01:00
user_namespace.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
user.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-28 12:27:58 -08:00
utsname_sysctl.c sysctl: simplify ->strategy 2008-10-16 11:21:47 -07:00
utsname.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
wait.c wait: kill is_sync_wait() 2008-10-16 11:21:31 -07:00
workqueue.c work_on_cpu: Use our own workqueue. 2009-01-19 22:36:07 +01:00