From: Sebastian Andrzej Siewior Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. A lot of code is removed because the for-loop is used and create_hash_tables() is removed since its purpose is covered by the startup / teardown hooks. Signed-off-by: Sebastian Andrzej Siewior Cc: Andrew Morton Cc: Arnd Bergmann Cc: Linus Torvalds Cc: Mel Gorman Cc: Michal Hocko Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vlastimil Babka Signed-off-by: Anna-Maria Gleixner --- include/linux/cpuhotplug.h | 1 + kernel/profile.c | 181 ++++++++++++++++----------------------------- 2 files changed, 66 insertions(+), 116 deletions(-) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index e0f8bfd..a38fb6f 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -17,6 +17,7 @@ enum cpuhp_state { CPUHP_WORKQUEUE_PREP, CPUHP_POWER_NUMA_PREPARE, CPUHP_HRTIMERS_PREPARE, + CPUHP_PROFILE_PREPARE, CPUHP_TIMERS_DEAD, CPUHP_NOTIFY_PREPARE, CPUHP_BRINGUP_CPU, diff --git a/kernel/profile.c b/kernel/profile.c index c2199e9..2dbccf2 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -328,68 +328,57 @@ out: put_cpu(); } -static int profile_cpu_callback(struct notifier_block *info, - unsigned long action, void *__cpu) +static int profile_dead_cpu(unsigned int cpu) { - int node, cpu = (unsigned long)__cpu; struct page *page; + int i; - switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - node = cpu_to_mem(cpu); - per_cpu(cpu_profile_flip, cpu) = 0; - if (!per_cpu(cpu_profile_hits, cpu)[1]) { - page = __alloc_pages_node(node, - GFP_KERNEL | __GFP_ZERO, - 0); - if (!page) - return notifier_from_errno(-ENOMEM); - per_cpu(cpu_profile_hits, cpu)[1] = page_address(page); - } - if (!per_cpu(cpu_profile_hits, cpu)[0]) { - page = __alloc_pages_node(node, - GFP_KERNEL | __GFP_ZERO, - 0); - if (!page) - goto out_free; - per_cpu(cpu_profile_hits, cpu)[0] = page_address(page); - } - break; -out_free: - page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); - per_cpu(cpu_profile_hits, cpu)[1] = NULL; - __free_page(page); - return notifier_from_errno(-ENOMEM); - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - if (prof_cpu_mask != NULL) - cpumask_set_cpu(cpu, prof_cpu_mask); - break; - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - case CPU_DEAD: - case CPU_DEAD_FROZEN: - if (prof_cpu_mask != NULL) - cpumask_clear_cpu(cpu, prof_cpu_mask); - if (per_cpu(cpu_profile_hits, cpu)[0]) { - page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); - per_cpu(cpu_profile_hits, cpu)[0] = NULL; + if (prof_cpu_mask != NULL) + cpumask_clear_cpu(cpu, prof_cpu_mask); + + for (i = 0; i < 2; i++) { + if (per_cpu(cpu_profile_hits, cpu)[i]) { + page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[i]); + per_cpu(cpu_profile_hits, cpu)[i] = NULL; __free_page(page); } - if (per_cpu(cpu_profile_hits, cpu)[1]) { - page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); - per_cpu(cpu_profile_hits, cpu)[1] = NULL; - __free_page(page); + } + return 0; +} + +static int profile_prepare_cpu(unsigned int cpu) +{ + int i, node = cpu_to_mem(cpu); + struct page *page; + + per_cpu(cpu_profile_flip, cpu) = 0; + + for (i = 0; i < 2; i++) { + if (per_cpu(cpu_profile_hits, cpu)[i]) + continue; + + page = __alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); + if (!page) { + profile_dead_cpu(cpu); + return -ENOMEM; } - break; + per_cpu(cpu_profile_hits, cpu)[i] = page_address(page); + } - return NOTIFY_OK; + return 0; +} + +static int profile_online_cpu(unsigned int cpu) +{ + if (prof_cpu_mask != NULL) + cpumask_set_cpu(cpu, prof_cpu_mask); + + return 0; } + #else /* !CONFIG_SMP */ #define profile_flip_buffers() do { } while (0) #define profile_discard_flip_buffers() do { } while (0) -#define profile_cpu_callback NULL static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) { @@ -531,83 +520,43 @@ static const struct file_operations proc_profile_operations = { .llseek = default_llseek, }; -#ifdef CONFIG_SMP -static void profile_nop(void *unused) -{ -} - -static int create_hash_tables(void) +int __ref create_proc_profile(void) { - int cpu; - - for_each_online_cpu(cpu) { - int node = cpu_to_mem(cpu); - struct page *page; - - page = __alloc_pages_node(node, - GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE, - 0); - if (!page) - goto out_cleanup; - per_cpu(cpu_profile_hits, cpu)[1] - = (struct profile_hit *)page_address(page); - page = __alloc_pages_node(node, - GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE, - 0); - if (!page) - goto out_cleanup; - per_cpu(cpu_profile_hits, cpu)[0] - = (struct profile_hit *)page_address(page); - } - return 0; -out_cleanup: - prof_on = 0; - smp_mb(); - on_each_cpu(profile_nop, NULL, 1); - for_each_online_cpu(cpu) { - struct page *page; - - if (per_cpu(cpu_profile_hits, cpu)[0]) { - page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]); - per_cpu(cpu_profile_hits, cpu)[0] = NULL; - __free_page(page); - } - if (per_cpu(cpu_profile_hits, cpu)[1]) { - page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]); - per_cpu(cpu_profile_hits, cpu)[1] = NULL; - __free_page(page); - } - } - return -1; -} -#else -#define create_hash_tables() ({ 0; }) + struct proc_dir_entry *entry; +#ifdef CONFIG_SMP + enum cpuhp_state online_state; #endif -int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */ -{ - struct proc_dir_entry *entry; int err = 0; if (!prof_on) return 0; - - cpu_notifier_register_begin(); - - if (create_hash_tables()) { - err = -ENOMEM; - goto out; - } - +#ifdef CONFIG_SMP + err = cpuhp_setup_state(CPUHP_PROFILE_PREPARE, "PROFILE_PREPARE", + profile_prepare_cpu, profile_dead_cpu); + if (err) + return err; + + err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_PROFILE_ONLINE", + profile_online_cpu, NULL); + if (err < 0) + goto err_state_prep; + online_state = err; + err = 0; +#endif entry = proc_create("profile", S_IWUSR | S_IRUGO, NULL, &proc_profile_operations); if (!entry) - goto out; + goto err_state_onl; proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); - __hotcpu_notifier(profile_cpu_callback, 0); -out: - cpu_notifier_register_done(); + return err; +err_state_onl: +#ifdef CONFIG_SMP + cpuhp_remove_state(online_state); +err_state_prep: + cpuhp_remove_state(CPUHP_PROFILE_PREPARE); +#endif return err; } subsys_initcall(create_proc_profile); -- 2.8.1