Implement timer_top statistics v8. Original code by Daniel Petrini Updated by Con Kolivas Signed-off-by: Con Kolivas include/linux/dyntick.h | 14 ++ kernel/Makefile | 1 kernel/timer.c | 3 kernel/timer_top.c | 234 ++++++++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 13 ++ 5 files changed, 265 insertions(+) Index: linux-2.6.16-rc5-dt/kernel/Makefile =================================================================== --- linux-2.6.16-rc5-dt.orig/kernel/Makefile 2006-02-27 20:30:47.000000000 +1100 +++ linux-2.6.16-rc5-dt/kernel/Makefile 2006-02-27 20:32:57.000000000 +1100 @@ -35,6 +35,7 @@ obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_SECCOMP) += seccomp.o obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o obj-$(CONFIG_NO_IDLE_HZ) += dyntick.o +obj-$(CONFIG_TIMER_INFO) += timer_top.o ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) # According to Alan Modra , the -fno-omit-frame-pointer is Index: linux-2.6.16-rc5-dt/kernel/timer.c =================================================================== --- linux-2.6.16-rc5-dt.orig/kernel/timer.c 2006-02-27 20:30:47.000000000 +1100 +++ linux-2.6.16-rc5-dt/kernel/timer.c 2006-02-27 20:32:57.000000000 +1100 @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -541,6 +542,8 @@ found: expires = nte->expires; } } + account_timer((unsigned long)nte->function, nte->data); + spin_unlock(&base->t_base.lock); return expires; } Index: linux-2.6.16-rc5-dt/kernel/timer_top.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.16-rc5-dt/kernel/timer_top.c 2006-02-27 20:32:57.000000000 +1100 @@ -0,0 +1,234 @@ +/* + * kernel/timer_top.c + * + * Export Timers information to /proc/timer_info + * + * Copyright (C) 2005 Instituto Nokia de Tecnologia - INdT - Manaus + * Written by Daniel Petrini + * + * This utility should be used to get information from the system timers + * and maybe optimize the system once you know which timers are being used + * and the process which starts them. + * This is particular useful above dynamic tick implementation. One can + * see who is starting timers and make the HZ value increase. + * + * We export the addresses and counting of timer functions being called, + * the pid and cmdline from the owner process if applicable. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + + +#include +#include +#include +#include +#include +#include +#include + +#define VERSION "Timer Top v0.9.8" + +struct timer_top_info { + unsigned int func_pointer; + unsigned long counter; + pid_t pid; + char comm[TASK_COMM_LEN]; + struct list_head list; +}; + +struct timer_top_root { + spinlock_t lock; + struct list_head list; + kmem_cache_t *cache; + int record; /* if currently collecting data */ +}; + +static struct timer_top_root top_root = { + .lock = SPIN_LOCK_UNLOCKED, + .list = LIST_HEAD_INIT(top_root.list), +}; + +static struct list_head *timer_list = &top_root.list; +static spinlock_t *top_lock = &top_root.lock; + +static inline int update_top_info(unsigned long function, pid_t pid_info) +{ + struct timer_top_info *top; + + list_for_each_entry(top, timer_list, list) { + /* if it is in the list increment its count */ + if (top->func_pointer == function && top->pid == pid_info) { + top->counter++; + return 1; + } + } + + return 0; +} + +int account_timer(unsigned long function, unsigned long data) +{ + struct timer_top_info *top; + struct task_struct * task_info; + pid_t pid_info = 0; + char name[TASK_COMM_LEN] = ""; + unsigned long flags; + + if (!top_root.record) + goto out; + + spin_lock_irqsave(top_lock, flags); + + if (data) { + task_info = (struct task_struct *) data; + /* little sanity ... not enough yet */ + if ((task_info->pid > 0) && (task_info->pid < PID_MAX_LIMIT)) { + pid_info = task_info->pid; + strncpy(name, task_info->comm, sizeof(task_info->comm)); + } + } + + if (update_top_info(function, pid_info)) + goto out_unlock; + + /* Function not found so insert it in the list */ + top = kmem_cache_alloc(top_root.cache, GFP_ATOMIC); + if (unlikely(!top)) + goto out_unlock; + + top->func_pointer = function; + top->counter = 1; + top->pid = pid_info; + strncpy(top->comm, name, sizeof(name)); + list_add(&top->list, timer_list); + +out_unlock: + spin_unlock_irqrestore(top_lock, flags); + +out: + return 0; +} + +EXPORT_SYMBOL(account_timer); + +/* + * Must hold top_lock + */ +static void timer_list_del(void) +{ + struct list_head *aux1, *aux2; + struct timer_top_info *entry; + + list_for_each_safe(aux1, aux2, timer_list) { + entry = list_entry(aux1, struct timer_top_info, list); + list_del(aux1); + kmem_cache_free(top_root.cache, entry); + } +} + +/* PROC_FS_SECTION */ + +static struct proc_dir_entry *top_info_file; +static struct proc_dir_entry *top_info_file_out; + +/* Statistics output - timer_info*/ +static int proc_read_top_info(struct seq_file *m, void *v) +{ + struct timer_top_info *top; + + seq_printf(m, "Function counter - %s\n", VERSION); + + list_for_each_entry(top, timer_list, list) { + seq_printf(m, "%x %lu %d %s\n", top->func_pointer, + top->counter, top->pid, top->comm); + } + + if (!top_root.record) + seq_printf(m, "Disabled\n"); + + return 0; +} + +static int proc_timertop_open(struct inode *inode, struct file *file) +{ + return single_open(file, proc_read_top_info, NULL); +} + +static struct file_operations proc_timertop_operations = { + .open = proc_timertop_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +#define MAX_INPUT_TOP 10 + +/* Receive some commands from user - timer_input */ +static int proc_write_timer_input(struct file *file, const char *page, + unsigned long count, void *data) +{ + int len; + char input_data[MAX_INPUT_TOP]; + unsigned long flags; + + /* input size checking */ + if (count > MAX_INPUT_TOP - 1) + len = MAX_INPUT_TOP - 1; + else + len = count; + + if (copy_from_user(input_data, page, len)) + return -EFAULT; + + input_data[len] = '\0'; + + spin_lock_irqsave(top_lock, flags); + if (!strncmp(input_data, "clear", 5)) + timer_list_del(); + else if (!strncmp(input_data, "start", 5)) + top_root.record = 1; + else if (!strncmp(input_data, "stop", 4)) { + top_root.record = 0; + timer_list_del(); + } + spin_unlock_irqrestore(top_lock, flags); + + return len; +} + +/* Print a sample string showing the possible inputs - timer_input */ +static int proc_read_timer_input(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len = sprintf(page, "clear start stop\n"); + + return len; +} + +static int __init init_top_info(void) +{ + top_root.cache = kmem_cache_create("top_info", + sizeof(struct timer_top_info), 0, SLAB_PANIC, NULL, NULL); + + top_info_file = create_proc_entry("timer_info", 0444, NULL); + if (top_info_file == NULL) + return -ENOMEM; + + top_info_file_out = create_proc_entry("timer_input", 0666, NULL); + if (top_info_file_out == NULL) + return -ENOMEM; + + /* Statistics output */ + top_info_file->proc_fops = &proc_timertop_operations; + + /* Control */ + top_info_file_out->write_proc = &proc_write_timer_input; + top_info_file_out->read_proc = &proc_read_timer_input; + + return 0; +} + +module_init(init_top_info); Index: linux-2.6.16-rc5-dt/lib/Kconfig.debug =================================================================== --- linux-2.6.16-rc5-dt.orig/lib/Kconfig.debug 2006-02-27 16:40:27.000000000 +1100 +++ linux-2.6.16-rc5-dt/lib/Kconfig.debug 2006-02-27 20:32:57.000000000 +1100 @@ -77,6 +77,19 @@ config SCHEDSTATS application, you can say N to avoid the very slight overhead this adds. +config TIMER_INFO + bool "Collect kernel timers statistics" + depends on DEBUG_KERNEL && PROC_FS && NO_IDLE_HZ + help + If you say Y here, additional code will be inserted into the + timer routines to collect statistics about kernel timers being + reprogrammed through dynamic ticks feature. The statistics + will be provided in /proc/timer_info and the behavior of this + feature can be controlled through /proc/timer_input. + The goal is to offer some output to let user applications show + timer pattern usage and allow some tuning in them to + maximise idle time. + config DEBUG_SLAB bool "Debug memory allocations" depends on DEBUG_KERNEL && SLAB Index: linux-2.6.16-rc5-dt/include/linux/dyntick.h =================================================================== --- linux-2.6.16-rc5-dt.orig/include/linux/dyntick.h 2006-02-27 20:30:47.000000000 +1100 +++ linux-2.6.16-rc5-dt/include/linux/dyntick.h 2006-02-27 20:32:57.000000000 +1100 @@ -119,6 +119,15 @@ static inline void set_nohz_cpu(int cpu) } } +#ifdef CONFIG_TIMER_INFO +extern int account_timer(unsigned long function, unsigned long data); +#else +static inline int account_timer(unsigned long function, unsigned long data) +{ + return 0; +} +#endif + #else /* CONFIG_NO_IDLE_HZ */ static inline int dyntick_enabled(void) { @@ -153,6 +162,11 @@ static inline void set_dyntick_limits(un static inline void dyn_early_reprogram(unsigned int delta) { } + +static inline int account_timer(unsigned long function, unsigned long data) +{ + return 0; +} #endif /* CONFIG_NO_IDLE_HZ */ #endif /* _dyntick_TIMER_H */