From c9d557c19f94df42db78d4a5de4d25feee694bad Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 7 Jan 2009 14:33:30 -0800 Subject: rcu: fix bug in rcutorture system-shutdown code This patch fixes an rcutorture bug found by Eric Sesterhenn that resulted in oopses in response to "rmmod rcutorture". The problem was in some new code that attempted to handle the case where a system is shut down while rcutorture is still running, for example, when rcutorture is built into the kernel so that it cannot be removed. The fix causes the rcutorture threads to "park" in an schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT) rather than trying to get them to terminate cleanly. Concurrent shutdown and rmmod is illegal. I believe that this is 2.6.29 material, as it is used in some testing setups. For reference, here are the rcutorture operating modes: CONFIG_RCU_TORTURE_TEST=m This is the normal rcutorture build. Use "modprobe rcutorture" (with optional arguments) to start, and "rmmod rcutorture" to stop. If you shut the system down without doing the rmmod, you should see console output like: rcutorture thread rcu_torture_writer parking due to system shutdown One for each rcutorture kthread. CONFIG_RCU_TORTURE_TEST=y CONFIG_RCU_TORTURE_TEST_RUNNABLE=n Use this if you want rcutorture built in, but don't want the test to start running during early boot. To start the torturing: echo 1 > /proc/sys/kernel/rcutorture_runnable To stop the torturing, s/1/0/ You will get "parking" console messages as noted above when you shut the system down. CONFIG_RCU_TORTURE_TEST=y CONFIG_RCU_TORTURE_TEST_RUNNABLE=y Same as above, except that the torturing starts during early boot. Only for the stout of heart and strong of stomach. The same /proc entry noted above may be used to control the test. Located-by: Eric Sesterhenn Tested-by: Eric Sesterhenn Signed-off-by: Paul E. McKenney Signed-off-by: Ingo Molnar --- kernel/rcutorture.c | 113 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 68 insertions(+), 45 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 1cff28db56b..7c4142a79f0 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -136,28 +136,46 @@ static int stutter_pause_test = 0; #endif int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; -#define FULLSTOP_SHUTDOWN 1 /* Bail due to system shutdown/panic. */ -#define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */ -static int fullstop; /* stop generating callbacks at test end. */ -DEFINE_MUTEX(fullstop_mutex); /* protect fullstop transitions and */ - /* spawning of kthreads. */ +/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ + +#define FULLSTOP_DONTSTOP 0 /* Normal operation. */ +#define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ +#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ +static int fullstop = FULLSTOP_RMMOD; +DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */ + /* of kthreads. */ /* - * Detect and respond to a signal-based shutdown. + * Detect and respond to a system shutdown. */ static int rcutorture_shutdown_notify(struct notifier_block *unused1, unsigned long unused2, void *unused3) { - if (fullstop) - return NOTIFY_DONE; mutex_lock(&fullstop_mutex); - if (!fullstop) + if (fullstop == FULLSTOP_DONTSTOP) fullstop = FULLSTOP_SHUTDOWN; + else + printk(KERN_WARNING /* but going down anyway, so... */ + "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); mutex_unlock(&fullstop_mutex); return NOTIFY_DONE; } +/* + * Absorb kthreads into a kernel function that won't return, so that + * they won't ever access module text or data again. + */ +static void rcutorture_shutdown_absorb(char *title) +{ + if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { + printk(KERN_NOTICE + "rcutorture thread %s parking due to system shutdown\n", + title); + schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); + } +} + /* * Allocate an element from the rcu_tortures pool. */ @@ -219,13 +237,14 @@ rcu_random(struct rcu_random_state *rrsp) } static void -rcu_stutter_wait(void) +rcu_stutter_wait(char *title) { - while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) { + while (stutter_pause_test || !rcutorture_runnable) { if (rcutorture_runnable) schedule_timeout_interruptible(1); else schedule_timeout_interruptible(round_jiffies_relative(HZ)); + rcutorture_shutdown_absorb(title); } } @@ -287,7 +306,7 @@ rcu_torture_cb(struct rcu_head *p) int i; struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); - if (fullstop) { + if (fullstop != FULLSTOP_DONTSTOP) { /* Test is ending, just drop callbacks on the floor. */ /* The next initialization will pick up the pieces. */ return; @@ -619,10 +638,11 @@ rcu_torture_writer(void *arg) } rcu_torture_current_version++; oldbatch = cur_ops->completed(); - rcu_stutter_wait(); - } while (!kthread_should_stop() && !fullstop); + rcu_stutter_wait("rcu_torture_writer"); + } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); - while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN) + rcutorture_shutdown_absorb("rcu_torture_writer"); + while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; } @@ -643,11 +663,12 @@ rcu_torture_fakewriter(void *arg) schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); udelay(rcu_random(&rand) & 0x3ff); cur_ops->sync(); - rcu_stutter_wait(); - } while (!kthread_should_stop() && !fullstop); + rcu_stutter_wait("rcu_torture_fakewriter"); + } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); - while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN) + rcutorture_shutdown_absorb("rcu_torture_fakewriter"); + while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; } @@ -752,12 +773,13 @@ rcu_torture_reader(void *arg) preempt_enable(); cur_ops->readunlock(idx); schedule(); - rcu_stutter_wait(); - } while (!kthread_should_stop() && !fullstop); + rcu_stutter_wait("rcu_torture_reader"); + } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); + rcutorture_shutdown_absorb("rcu_torture_reader"); if (irqreader && cur_ops->irqcapable) del_timer_sync(&t); - while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN) + while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; } @@ -854,7 +876,8 @@ rcu_torture_stats(void *arg) do { schedule_timeout_interruptible(stat_interval * HZ); rcu_torture_stats_print(); - } while (!kthread_should_stop() && !fullstop); + rcutorture_shutdown_absorb("rcu_torture_stats"); + } while (!kthread_should_stop()); VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); return 0; } @@ -866,52 +889,49 @@ static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ */ static void rcu_torture_shuffle_tasks(void) { - cpumask_var_t tmp_mask; + cpumask_t tmp_mask; int i; - if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL)) - BUG(); - - cpumask_setall(tmp_mask); + cpus_setall(tmp_mask); get_online_cpus(); /* No point in shuffling if there is only one online CPU (ex: UP) */ - if (num_online_cpus() == 1) - goto out; + if (num_online_cpus() == 1) { + put_online_cpus(); + return; + } if (rcu_idle_cpu != -1) - cpumask_clear_cpu(rcu_idle_cpu, tmp_mask); + cpu_clear(rcu_idle_cpu, tmp_mask); - set_cpus_allowed_ptr(current, tmp_mask); + set_cpus_allowed_ptr(current, &tmp_mask); if (reader_tasks) { for (i = 0; i < nrealreaders; i++) if (reader_tasks[i]) set_cpus_allowed_ptr(reader_tasks[i], - tmp_mask); + &tmp_mask); } if (fakewriter_tasks) { for (i = 0; i < nfakewriters; i++) if (fakewriter_tasks[i]) set_cpus_allowed_ptr(fakewriter_tasks[i], - tmp_mask); + &tmp_mask); } if (writer_task) - set_cpus_allowed_ptr(writer_task, tmp_mask); + set_cpus_allowed_ptr(writer_task, &tmp_mask); if (stats_task) - set_cpus_allowed_ptr(stats_task, tmp_mask); + set_cpus_allowed_ptr(stats_task, &tmp_mask); if (rcu_idle_cpu == -1) rcu_idle_cpu = num_online_cpus() - 1; else rcu_idle_cpu--; -out: put_online_cpus(); - free_cpumask_var(tmp_mask); } /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the @@ -925,7 +945,8 @@ rcu_torture_shuffle(void *arg) do { schedule_timeout_interruptible(shuffle_interval * HZ); rcu_torture_shuffle_tasks(); - } while (!kthread_should_stop() && !fullstop); + rcutorture_shutdown_absorb("rcu_torture_shuffle"); + } while (!kthread_should_stop()); VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); return 0; } @@ -940,10 +961,11 @@ rcu_torture_stutter(void *arg) do { schedule_timeout_interruptible(stutter * HZ); stutter_pause_test = 1; - if (!kthread_should_stop() && !fullstop) + if (!kthread_should_stop()) schedule_timeout_interruptible(stutter * HZ); stutter_pause_test = 0; - } while (!kthread_should_stop() && !fullstop); + rcutorture_shutdown_absorb("rcu_torture_stutter"); + } while (!kthread_should_stop()); VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); return 0; } @@ -970,15 +992,16 @@ rcu_torture_cleanup(void) int i; mutex_lock(&fullstop_mutex); - if (!fullstop) { - /* If being signaled, let it happen, then exit. */ + if (fullstop == FULLSTOP_SHUTDOWN) { + printk(KERN_WARNING /* but going down anyway, so... */ + "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); mutex_unlock(&fullstop_mutex); - schedule_timeout_interruptible(10 * HZ); + schedule_timeout_uninterruptible(10); if (cur_ops->cb_barrier != NULL) cur_ops->cb_barrier(); return; } - fullstop = FULLSTOP_CLEANUP; + fullstop = FULLSTOP_RMMOD; mutex_unlock(&fullstop_mutex); unregister_reboot_notifier(&rcutorture_nb); if (stutter_task) { @@ -1078,7 +1101,7 @@ rcu_torture_init(void) else nrealreaders = 2 * num_online_cpus(); rcu_torture_print_module_parms("Start of test"); - fullstop = 0; + fullstop = FULLSTOP_DONTSTOP; /* Set up the freelist. */ -- cgit v1.2.3 From 62ea9ceb17a74bc7544211bfeecf4170c554ac4f Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 11 Jan 2009 01:04:16 +0100 Subject: cpumask: fix CONFIG_NUMA=y sched.c Impact: fix panic on ia64 with NR_CPUS=1024 struct sched_domain is now a dangling structure; where we really want static ones, we need to use static_sched_domain. (As the FIXME in this file says, cpumask_var_t would be better, but this code is hairy enough without trying to add initialization code to the right places). Reported-by: Mike Travis Signed-off-by: Rusty Russell Signed-off-by: Ingo Molnar --- kernel/sched.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index deb5ac8c12f..f0c0a81d763 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7282,10 +7282,10 @@ cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, * groups, so roll our own. Now each node has its own list of groups which * gets dynamically allocated. */ -static DEFINE_PER_CPU(struct sched_domain, node_domains); +static DEFINE_PER_CPU(struct static_sched_domain, node_domains); static struct sched_group ***sched_group_nodes_bycpu; -static DEFINE_PER_CPU(struct sched_domain, allnodes_domains); +static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, @@ -7560,7 +7560,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, #ifdef CONFIG_NUMA if (cpumask_weight(cpu_map) > SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) { - sd = &per_cpu(allnodes_domains, i); + sd = &per_cpu(allnodes_domains, i).sd; SD_INIT(sd, ALLNODES); set_domain_attribute(sd, attr); cpumask_copy(sched_domain_span(sd), cpu_map); @@ -7570,7 +7570,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, } else p = NULL; - sd = &per_cpu(node_domains, i); + sd = &per_cpu(node_domains, i).sd; SD_INIT(sd, NODE); set_domain_attribute(sd, attr); sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); @@ -7688,7 +7688,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, for_each_cpu(j, nodemask) { struct sched_domain *sd; - sd = &per_cpu(node_domains, j); + sd = &per_cpu(node_domains, j).sd; sd->groups = sg; } sg->__cpu_power = 0; -- cgit v1.2.3 From 805194c35b91999b139e4d6b6145f4f84fd4c814 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Sat, 10 Jan 2009 15:43:15 +0800 Subject: sched: partly revert "sched debug: remove NULL checking in print_cfs_rt_rq()" Impact: avoid accessing NULL tg.css->cgroup In commit 0a0db8f5c9d4bbb9bbfcc2b6cb6bce2d0ef4d73d, I removed checking NULL tg.css->cgroup, but I realized I was wrong when I found reading /proc/sched_debug can race with cgroup_create(). Signed-off-by: Li Zefan Signed-off-by: Ingo Molnar --- kernel/sched_debug.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 4293cfa9681..16eeba4e416 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -145,6 +145,19 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) read_unlock_irqrestore(&tasklist_lock, flags); } +#if defined(CONFIG_CGROUP_SCHED) && \ + (defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)) +static void task_group_path(struct task_group *tg, char *buf, int buflen) +{ + /* may be NULL if the underlying cgroup isn't fully-created yet */ + if (!tg->css.cgroup) { + buf[0] = '\0'; + return; + } + cgroup_path(tg->css.cgroup, buf, buflen); +} +#endif + void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) { s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1, @@ -154,10 +167,10 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) unsigned long flags; #if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED) - char path[128] = ""; + char path[128]; struct task_group *tg = cfs_rq->tg; - cgroup_path(tg->css.cgroup, path, sizeof(path)); + task_group_path(tg, path, sizeof(path)); SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path); #elif defined(CONFIG_USER_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED) @@ -208,10 +221,10 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq) { #if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED) - char path[128] = ""; + char path[128]; struct task_group *tg = rt_rq->tg; - cgroup_path(tg->css.cgroup, path, sizeof(path)); + task_group_path(tg, path, sizeof(path)); SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path); #else -- cgit v1.2.3 From 53ce3d9564908794ae7dd32969089b57df5fc098 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Fri, 9 Jan 2009 12:27:08 -0800 Subject: smp_call_function_single(): be slightly less stupid If you do smp_call_function_single(expression-with-side-effects, ...) then expression-with-side-effects never gets evaluated on UP builds. As always, implementing it in C is the correct thing to do. While we're there, uninline it for size and possible header dependency reasons. And create a new kernel/up.c, as a place in which to put uniprocessor-specific code and storage. It should mirror kernel/smp.c. Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/Makefile | 6 +++++- kernel/up.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) create mode 100644 kernel/up.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 2921d90ce32..2aebc4cd787 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -40,7 +40,11 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o -obj-$(CONFIG_USE_GENERIC_SMP_HELPERS) += smp.o +ifeq ($(CONFIG_USE_GENERIC_SMP_HELPERS),y) +obj-y += smp.o +else +obj-y += up.o +endif obj-$(CONFIG_SMP) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o diff --git a/kernel/up.c b/kernel/up.c new file mode 100644 index 00000000000..ce62cc9e9f7 --- /dev/null +++ b/kernel/up.c @@ -0,0 +1,18 @@ +/* + * Uniprocessor-only support functions. The counterpart to kernel/smp.c + */ + +#include +#include +#include + +int smp_call_function_single(int cpu, void (*func) (void *info), void *info, + int wait) +{ + WARN_ON(cpuid != 0); + local_irq_disable(); + (func)(info); + local_irq_enable(); + return 0; +} +EXPORT_SYMBOL(smp_call_function_single); -- cgit v1.2.3 From 93423b8665f43a0c7a006a1d5be048b99db56d32 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 11 Jan 2009 05:15:21 +0100 Subject: smp_call_function_single(): be slightly less stupid, fix Impact: build fix on Alpha kernel/up.c: In function 'smp_call_function_single': kernel/up.c:12: error: 'cpuid' undeclared (first use in this function) kernel/up.c:12: error: (Each undeclared identifier is reported only once kernel/up.c:12: error: for each function it appears in.) The typo didnt show up on x86 because 'cpuid' happens to be a function address as well ... Signed-off-by: Ingo Molnar --- kernel/up.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/up.c b/kernel/up.c index ce62cc9e9f7..c04b9dcfceb 100644 --- a/kernel/up.c +++ b/kernel/up.c @@ -9,10 +9,12 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int wait) { - WARN_ON(cpuid != 0); + WARN_ON(cpu != 0); + local_irq_disable(); (func)(info); local_irq_enable(); + return 0; } EXPORT_SYMBOL(smp_call_function_single); -- cgit v1.2.3 From fd2ab30b65e961b974ae0bc71e0d47d6b35e0968 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Sun, 11 Jan 2009 01:04:22 -0800 Subject: kernel/sched.c: add missing forward declaration for 'double_rq_lock' Impact: build fix on certain configs Added 'double_rq_lock' forward declaration, allowing double_rq_lock to be used in _double_lock_balance(). Signed-off-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/sched.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index f0c0a81d763..8be2c13b50d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -125,6 +125,9 @@ DEFINE_TRACE(sched_switch); DEFINE_TRACE(sched_migrate_task); #ifdef CONFIG_SMP + +static void double_rq_lock(struct rq *rq1, struct rq *rq2); + /* * Divide a load by a sched group cpu_power : (load / sg->__cpu_power) * Since cpu_power is a 'constant', we can use a reciprocal divide. -- cgit v1.2.3 From 6e96281412f2f757abe623e08a9577e2bbd3402f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 Jan 2009 16:04:37 +0100 Subject: smp_call_function_single(): be slightly less stupid, fix #2 fix m68k build failure: tip/kernel/up.c: In function 'smp_call_function_single': tip/kernel/up.c:16: error: dereferencing pointer to incomplete type make[2]: *** [kernel/up.o] Error 1 Signed-off-by: Ingo Molnar --- kernel/up.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/up.c b/kernel/up.c index c04b9dcfceb..1ff27a28bb7 100644 --- a/kernel/up.c +++ b/kernel/up.c @@ -2,6 +2,7 @@ * Uniprocessor-only support functions. The counterpart to kernel/smp.c */ +#include #include #include #include -- cgit v1.2.3 From 37a76bd4f1b716949fc38a6842e89f0ccb8384d0 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 11 Jan 2009 15:35:01 +0000 Subject: async: fix __lowest_in_progress() At 37000 feet somewhere near Greenland I woke up from a half-sleep with the realisation that __lowest_in_progress() is buggy. After landing I checked and there were indeed 2 problems with it; this patch fixes both: * The order of the list checks was wrong * The locking was not correct. Signed-off-by: Arjan van de Ven Signed-off-by: Linus Torvalds --- kernel/async.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/async.c b/kernel/async.c index f286e9f2b73..608b32b4281 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -90,12 +90,12 @@ extern int initcall_debug; static async_cookie_t __lowest_in_progress(struct list_head *running) { struct async_entry *entry; - if (!list_empty(&async_pending)) { - entry = list_first_entry(&async_pending, + if (!list_empty(running)) { + entry = list_first_entry(running, struct async_entry, list); return entry->cookie; - } else if (!list_empty(running)) { - entry = list_first_entry(running, + } else if (!list_empty(&async_pending)) { + entry = list_first_entry(&async_pending, struct async_entry, list); return entry->cookie; } else { @@ -104,6 +104,17 @@ static async_cookie_t __lowest_in_progress(struct list_head *running) } } + +static async_cookie_t lowest_in_progress(struct list_head *running) +{ + unsigned long flags; + async_cookie_t ret; + + spin_lock_irqsave(&async_lock, flags); + ret = __lowest_in_progress(running); + spin_unlock_irqrestore(&async_lock, flags); + return ret; +} /* * pick the first pending entry and run it */ @@ -229,7 +240,7 @@ void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *r starttime = ktime_get(); } - wait_event(async_done, __lowest_in_progress(running) >= cookie); + wait_event(async_done, lowest_in_progress(running) >= cookie); if (initcall_debug && system_state == SYSTEM_BOOTING) { endtime = ktime_get(); -- cgit v1.2.3