mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
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909 lines
25 KiB
Diff
909 lines
25 KiB
Diff
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From 0407c7a2f4734cd55902753d788fdbdc32ed7fd9 Mon Sep 17 00:00:00 2001
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From: Kees Cook <keescook@chromium.org>
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Date: Wed, 08 Feb 2017 11:26:59 -0800
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Subject: [PATCH] time: Remove CONFIG_TIMER_STATS
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Currently CONFIG_TIMER_STATS exposes process information across namespaces:
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kernel/time/timer_list.c print_timer():
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SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
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/proc/timer_list:
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#11: <0000000000000000>, hrtimer_wakeup, S:01, do_nanosleep, cron/2570
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Given that the tracer can give the same information, this patch entirely
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removes CONFIG_TIMER_STATS.
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Change-Id: Ice26d74094d3ad563808342c1604ad444234844b
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Suggested-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: Kees Cook <keescook@chromium.org>
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Acked-by: John Stultz <john.stultz@linaro.org>
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Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
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Cc: linux-doc@vger.kernel.org
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Cc: Lai Jiangshan <jiangshanlai@gmail.com>
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Cc: Shuah Khan <shuah@kernel.org>
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Cc: Xing Gao <xgao01@email.wm.edu>
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Cc: Jonathan Corbet <corbet@lwn.net>
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Cc: Jessica Frazelle <me@jessfraz.com>
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Cc: kernel-hardening@lists.openwall.com
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Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
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Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
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Cc: Petr Mladek <pmladek@suse.com>
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Cc: Richard Cochran <richardcochran@gmail.com>
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Cc: Tejun Heo <tj@kernel.org>
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Cc: Michal Marek <mmarek@suse.com>
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Cc: Josh Poimboeuf <jpoimboe@redhat.com>
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Cc: Dmitry Vyukov <dvyukov@google.com>
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Cc: Oleg Nesterov <oleg@redhat.com>
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Cc: "Eric W. Biederman" <ebiederm@xmission.com>
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Cc: Olof Johansson <olof@lixom.net>
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Cc: Andrew Morton <akpm@linux-foundation.org>
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Cc: linux-api@vger.kernel.org
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Cc: Arjan van de Ven <arjan@linux.intel.com>
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Link: http://lkml.kernel.org/r/20170208192659.GA32582@beast
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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---
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diff --git a/Documentation/timers/timer_stats.txt b/Documentation/timers/timer_stats.txt
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deleted file mode 100644
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index 8abd40b..0000000
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--- a/Documentation/timers/timer_stats.txt
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+++ /dev/null
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@@ -1,73 +0,0 @@
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-timer_stats - timer usage statistics
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-------------------------------------
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-
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-timer_stats is a debugging facility to make the timer (ab)usage in a Linux
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-system visible to kernel and userspace developers. If enabled in the config
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-but not used it has almost zero runtime overhead, and a relatively small
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-data structure overhead. Even if collection is enabled runtime all the
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-locking is per-CPU and lookup is hashed.
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-
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-timer_stats should be used by kernel and userspace developers to verify that
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-their code does not make unduly use of timers. This helps to avoid unnecessary
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-wakeups, which should be avoided to optimize power consumption.
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-
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-It can be enabled by CONFIG_TIMER_STATS in the "Kernel hacking" configuration
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-section.
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-
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-timer_stats collects information about the timer events which are fired in a
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-Linux system over a sample period:
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-
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-- the pid of the task(process) which initialized the timer
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-- the name of the process which initialized the timer
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-- the function where the timer was initialized
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-- the callback function which is associated to the timer
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-- the number of events (callbacks)
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-
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-timer_stats adds an entry to /proc: /proc/timer_stats
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-
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-This entry is used to control the statistics functionality and to read out the
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-sampled information.
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-
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-The timer_stats functionality is inactive on bootup.
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-
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-To activate a sample period issue:
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-# echo 1 >/proc/timer_stats
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-
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-To stop a sample period issue:
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-# echo 0 >/proc/timer_stats
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-
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-The statistics can be retrieved by:
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-# cat /proc/timer_stats
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-
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-The readout of /proc/timer_stats automatically disables sampling. The sampled
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-information is kept until a new sample period is started. This allows multiple
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-readouts.
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-
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-Sample output of /proc/timer_stats:
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-
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-Timerstats sample period: 3.888770 s
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- 12, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
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- 15, 1 swapper hcd_submit_urb (rh_timer_func)
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- 4, 959 kedac schedule_timeout (process_timeout)
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- 1, 0 swapper page_writeback_init (wb_timer_fn)
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- 28, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
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- 22, 2948 IRQ 4 tty_flip_buffer_push (delayed_work_timer_fn)
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- 3, 3100 bash schedule_timeout (process_timeout)
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- 1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
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- 1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
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- 1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer)
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- 1, 2292 ip __netdev_watchdog_up (dev_watchdog)
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- 1, 23 events/1 do_cache_clean (delayed_work_timer_fn)
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-90 total events, 30.0 events/sec
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-
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-The first column is the number of events, the second column the pid, the third
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-column is the name of the process. The forth column shows the function which
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-initialized the timer and in parenthesis the callback function which was
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-executed on expiry.
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-
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- Thomas, Ingo
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-
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-Added flag to indicate 'deferrable timer' in /proc/timer_stats. A deferrable
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-timer will appear as follows
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- 10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
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-
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diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
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index 0302bbe..765d9e7 100644
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--- a/include/linux/hrtimer.h
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+++ b/include/linux/hrtimer.h
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@@ -96,12 +96,6 @@
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* @function: timer expiry callback function
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* @base: pointer to the timer base (per cpu and per clock)
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* @state: state information (See bit values above)
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- * @start_site: timer statistics field to store the site where the timer
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- * was started
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- * @start_comm: timer statistics field to store the name of the process which
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- * started the timer
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- * @start_pid: timer statistics field to store the pid of the task which
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- * started the timer
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*
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* The hrtimer structure must be initialized by hrtimer_init()
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*/
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@@ -111,11 +105,6 @@
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enum hrtimer_restart (*function)(struct hrtimer *);
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struct hrtimer_clock_base *base;
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unsigned long state;
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-#ifdef CONFIG_TIMER_STATS
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- int start_pid;
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- void *start_site;
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- char start_comm[16];
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-#endif
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};
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/**
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diff --git a/include/linux/timer.h b/include/linux/timer.h
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index 8c5a197..7c8adfa 100644
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--- a/include/linux/timer.h
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+++ b/include/linux/timer.h
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@@ -23,11 +23,6 @@
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int slack;
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-#ifdef CONFIG_TIMER_STATS
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- int start_pid;
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- void *start_site;
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- char start_comm[16];
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-#endif
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#ifdef CONFIG_LOCKDEP
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struct lockdep_map lockdep_map;
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#endif
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@@ -193,49 +188,6 @@
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* jiffie.
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*/
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extern unsigned long get_next_timer_interrupt(unsigned long now);
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-
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-/*
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- * Timer-statistics info:
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- */
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-#ifdef CONFIG_TIMER_STATS
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-
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-extern int timer_stats_active;
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-
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-#define TIMER_STATS_FLAG_DEFERRABLE 0x1
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-
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-extern void init_timer_stats(void);
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-
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-extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
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- void *timerf, char *comm,
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- unsigned int timer_flag);
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-
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-extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
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- void *addr);
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-
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-static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
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-{
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- if (likely(!timer_stats_active))
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- return;
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- __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
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-}
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-
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-static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
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-{
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- timer->start_site = NULL;
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-}
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-#else
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-static inline void init_timer_stats(void)
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-{
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-}
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-
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-static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
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-{
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-}
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-
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-static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
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-{
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-}
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-#endif
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extern void add_timer(struct timer_list *timer);
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diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
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index 47067de..c9c3a6c 100644
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--- a/kernel/hrtimer.c
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+++ b/kernel/hrtimer.c
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@@ -827,34 +827,6 @@
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clock_was_set_delayed();
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}
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-static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
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-{
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-#ifdef CONFIG_TIMER_STATS
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- if (timer->start_site)
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- return;
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- timer->start_site = __builtin_return_address(0);
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- memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
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- timer->start_pid = current->pid;
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-#endif
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-}
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-
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-static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
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-{
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-#ifdef CONFIG_TIMER_STATS
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- timer->start_site = NULL;
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-#endif
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-}
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-
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-static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
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-{
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-#ifdef CONFIG_TIMER_STATS
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- if (likely(!timer_stats_active))
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- return;
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- timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
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- timer->function, timer->start_comm, 0);
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-#endif
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-}
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-
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/*
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* Counterpart to lock_hrtimer_base above:
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*/
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@@ -988,7 +960,6 @@
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* rare case and less expensive than a smp call.
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*/
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debug_deactivate(timer);
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- timer_stats_hrtimer_clear_start_info(timer);
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reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
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/*
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* We must preserve the CALLBACK state flag here,
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@@ -1033,8 +1004,6 @@
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/* Switch the timer base, if necessary: */
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new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
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-
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- timer_stats_hrtimer_set_start_info(timer);
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leftmost = enqueue_hrtimer(timer, new_base);
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@@ -1211,12 +1180,6 @@
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base = hrtimer_clockid_to_base(clock_id);
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timer->base = &cpu_base->clock_base[base];
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timerqueue_init(&timer->node);
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-
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-#ifdef CONFIG_TIMER_STATS
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- timer->start_site = NULL;
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- timer->start_pid = -1;
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- memset(timer->start_comm, 0, TASK_COMM_LEN);
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-#endif
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}
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/**
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@@ -1264,7 +1227,6 @@
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debug_deactivate(timer);
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__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
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- timer_stats_account_hrtimer(timer);
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fn = timer->function;
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/*
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diff --git a/kernel/time/Makefile b/kernel/time/Makefile
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index aa91af5..fd87e51 100644
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--- a/kernel/time/Makefile
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+++ b/kernel/time/Makefile
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@@ -7,4 +7,3 @@
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obj-$(CONFIG_GENERIC_SCHED_CLOCK) += sched_clock.o
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obj-$(CONFIG_TICK_ONESHOT) += tick-oneshot.o
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obj-$(CONFIG_TICK_ONESHOT) += tick-sched.o
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-obj-$(CONFIG_TIMER_STATS) += timer_stats.o
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diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
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index 61ed862..f6a1043 100644
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--- a/kernel/time/timer_list.c
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+++ b/kernel/time/timer_list.c
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@@ -57,21 +57,11 @@
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print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
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int idx, u64 now)
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{
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-#ifdef CONFIG_TIMER_STATS
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- char tmp[TASK_COMM_LEN + 1];
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-#endif
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SEQ_printf(m, " #%d: ", idx);
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print_name_offset(m, taddr);
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SEQ_printf(m, ", ");
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print_name_offset(m, timer->function);
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SEQ_printf(m, ", S:%02lx", timer->state);
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-#ifdef CONFIG_TIMER_STATS
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- SEQ_printf(m, ", ");
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- print_name_offset(m, timer->start_site);
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- memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
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- tmp[TASK_COMM_LEN] = 0;
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- SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
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-#endif
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SEQ_printf(m, "\n");
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SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
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(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
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diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
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deleted file mode 100644
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index 0b537f2..0000000
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--- a/kernel/time/timer_stats.c
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+++ /dev/null
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@@ -1,425 +0,0 @@
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-/*
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- * kernel/time/timer_stats.c
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- *
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- * Collect timer usage statistics.
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- *
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- * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
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- * Copyright(C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
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- *
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- * timer_stats is based on timer_top, a similar functionality which was part of
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- * Con Kolivas dyntick patch set. It was developed by Daniel Petrini at the
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- * Instituto Nokia de Tecnologia - INdT - Manaus. timer_top's design was based
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- * on dynamic allocation of the statistics entries and linear search based
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- * lookup combined with a global lock, rather than the static array, hash
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- * and per-CPU locking which is used by timer_stats. It was written for the
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- * pre hrtimer kernel code and therefore did not take hrtimers into account.
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- * Nevertheless it provided the base for the timer_stats implementation and
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- * was a helpful source of inspiration. Kudos to Daniel and the Nokia folks
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- * for this effort.
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- *
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- * timer_top.c is
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- * Copyright (C) 2005 Instituto Nokia de Tecnologia - INdT - Manaus
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- * Written by Daniel Petrini <d.pensator@gmail.com>
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- * timer_top.c was released under the GNU General Public License version 2
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- *
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- * We export the addresses and counting of timer functions being called,
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- * the pid and cmdline from the owner process if applicable.
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- *
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- * Start/stop data collection:
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- * # echo [1|0] >/proc/timer_stats
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- *
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- * Display the information collected so far:
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- * # cat /proc/timer_stats
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- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2 as
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- * published by the Free Software Foundation.
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- */
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-
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-#include <linux/proc_fs.h>
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||
|
-#include <linux/module.h>
|
||
|
-#include <linux/spinlock.h>
|
||
|
-#include <linux/sched.h>
|
||
|
-#include <linux/seq_file.h>
|
||
|
-#include <linux/kallsyms.h>
|
||
|
-
|
||
|
-#include <asm/uaccess.h>
|
||
|
-
|
||
|
-/*
|
||
|
- * This is our basic unit of interest: a timer expiry event identified
|
||
|
- * by the timer, its start/expire functions and the PID of the task that
|
||
|
- * started the timer. We count the number of times an event happens:
|
||
|
- */
|
||
|
-struct entry {
|
||
|
- /*
|
||
|
- * Hash list:
|
||
|
- */
|
||
|
- struct entry *next;
|
||
|
-
|
||
|
- /*
|
||
|
- * Hash keys:
|
||
|
- */
|
||
|
- void *timer;
|
||
|
- void *start_func;
|
||
|
- void *expire_func;
|
||
|
- pid_t pid;
|
||
|
-
|
||
|
- /*
|
||
|
- * Number of timeout events:
|
||
|
- */
|
||
|
- unsigned long count;
|
||
|
- unsigned int timer_flag;
|
||
|
-
|
||
|
- /*
|
||
|
- * We save the command-line string to preserve
|
||
|
- * this information past task exit:
|
||
|
- */
|
||
|
- char comm[TASK_COMM_LEN + 1];
|
||
|
-
|
||
|
-} ____cacheline_aligned_in_smp;
|
||
|
-
|
||
|
-/*
|
||
|
- * Spinlock protecting the tables - not taken during lookup:
|
||
|
- */
|
||
|
-static DEFINE_RAW_SPINLOCK(table_lock);
|
||
|
-
|
||
|
-/*
|
||
|
- * Per-CPU lookup locks for fast hash lookup:
|
||
|
- */
|
||
|
-static DEFINE_PER_CPU(raw_spinlock_t, tstats_lookup_lock);
|
||
|
-
|
||
|
-/*
|
||
|
- * Mutex to serialize state changes with show-stats activities:
|
||
|
- */
|
||
|
-static DEFINE_MUTEX(show_mutex);
|
||
|
-
|
||
|
-/*
|
||
|
- * Collection status, active/inactive:
|
||
|
- */
|
||
|
-int __read_mostly timer_stats_active;
|
||
|
-
|
||
|
-/*
|
||
|
- * Beginning/end timestamps of measurement:
|
||
|
- */
|
||
|
-static ktime_t time_start, time_stop;
|
||
|
-
|
||
|
-/*
|
||
|
- * tstat entry structs only get allocated while collection is
|
||
|
- * active and never freed during that time - this simplifies
|
||
|
- * things quite a bit.
|
||
|
- *
|
||
|
- * They get freed when a new collection period is started.
|
||
|
- */
|
||
|
-#define MAX_ENTRIES_BITS 10
|
||
|
-#define MAX_ENTRIES (1UL << MAX_ENTRIES_BITS)
|
||
|
-
|
||
|
-static unsigned long nr_entries;
|
||
|
-static struct entry entries[MAX_ENTRIES];
|
||
|
-
|
||
|
-static atomic_t overflow_count;
|
||
|
-
|
||
|
-/*
|
||
|
- * The entries are in a hash-table, for fast lookup:
|
||
|
- */
|
||
|
-#define TSTAT_HASH_BITS (MAX_ENTRIES_BITS - 1)
|
||
|
-#define TSTAT_HASH_SIZE (1UL << TSTAT_HASH_BITS)
|
||
|
-#define TSTAT_HASH_MASK (TSTAT_HASH_SIZE - 1)
|
||
|
-
|
||
|
-#define __tstat_hashfn(entry) \
|
||
|
- (((unsigned long)(entry)->timer ^ \
|
||
|
- (unsigned long)(entry)->start_func ^ \
|
||
|
- (unsigned long)(entry)->expire_func ^ \
|
||
|
- (unsigned long)(entry)->pid ) & TSTAT_HASH_MASK)
|
||
|
-
|
||
|
-#define tstat_hashentry(entry) (tstat_hash_table + __tstat_hashfn(entry))
|
||
|
-
|
||
|
-static struct entry *tstat_hash_table[TSTAT_HASH_SIZE] __read_mostly;
|
||
|
-
|
||
|
-static void reset_entries(void)
|
||
|
-{
|
||
|
- nr_entries = 0;
|
||
|
- memset(entries, 0, sizeof(entries));
|
||
|
- memset(tstat_hash_table, 0, sizeof(tstat_hash_table));
|
||
|
- atomic_set(&overflow_count, 0);
|
||
|
-}
|
||
|
-
|
||
|
-static struct entry *alloc_entry(void)
|
||
|
-{
|
||
|
- if (nr_entries >= MAX_ENTRIES)
|
||
|
- return NULL;
|
||
|
-
|
||
|
- return entries + nr_entries++;
|
||
|
-}
|
||
|
-
|
||
|
-static int match_entries(struct entry *entry1, struct entry *entry2)
|
||
|
-{
|
||
|
- return entry1->timer == entry2->timer &&
|
||
|
- entry1->start_func == entry2->start_func &&
|
||
|
- entry1->expire_func == entry2->expire_func &&
|
||
|
- entry1->pid == entry2->pid;
|
||
|
-}
|
||
|
-
|
||
|
-/*
|
||
|
- * Look up whether an entry matching this item is present
|
||
|
- * in the hash already. Must be called with irqs off and the
|
||
|
- * lookup lock held:
|
||
|
- */
|
||
|
-static struct entry *tstat_lookup(struct entry *entry, char *comm)
|
||
|
-{
|
||
|
- struct entry **head, *curr, *prev;
|
||
|
-
|
||
|
- head = tstat_hashentry(entry);
|
||
|
- curr = *head;
|
||
|
-
|
||
|
- /*
|
||
|
- * The fastpath is when the entry is already hashed,
|
||
|
- * we do this with the lookup lock held, but with the
|
||
|
- * table lock not held:
|
||
|
- */
|
||
|
- while (curr) {
|
||
|
- if (match_entries(curr, entry))
|
||
|
- return curr;
|
||
|
-
|
||
|
- curr = curr->next;
|
||
|
- }
|
||
|
- /*
|
||
|
- * Slowpath: allocate, set up and link a new hash entry:
|
||
|
- */
|
||
|
- prev = NULL;
|
||
|
- curr = *head;
|
||
|
-
|
||
|
- raw_spin_lock(&table_lock);
|
||
|
- /*
|
||
|
- * Make sure we have not raced with another CPU:
|
||
|
- */
|
||
|
- while (curr) {
|
||
|
- if (match_entries(curr, entry))
|
||
|
- goto out_unlock;
|
||
|
-
|
||
|
- prev = curr;
|
||
|
- curr = curr->next;
|
||
|
- }
|
||
|
-
|
||
|
- curr = alloc_entry();
|
||
|
- if (curr) {
|
||
|
- *curr = *entry;
|
||
|
- curr->count = 0;
|
||
|
- curr->next = NULL;
|
||
|
- memcpy(curr->comm, comm, TASK_COMM_LEN);
|
||
|
-
|
||
|
- smp_mb(); /* Ensure that curr is initialized before insert */
|
||
|
-
|
||
|
- if (prev)
|
||
|
- prev->next = curr;
|
||
|
- else
|
||
|
- *head = curr;
|
||
|
- }
|
||
|
- out_unlock:
|
||
|
- raw_spin_unlock(&table_lock);
|
||
|
-
|
||
|
- return curr;
|
||
|
-}
|
||
|
-
|
||
|
-/**
|
||
|
- * timer_stats_update_stats - Update the statistics for a timer.
|
||
|
- * @timer: pointer to either a timer_list or a hrtimer
|
||
|
- * @pid: the pid of the task which set up the timer
|
||
|
- * @startf: pointer to the function which did the timer setup
|
||
|
- * @timerf: pointer to the timer callback function of the timer
|
||
|
- * @comm: name of the process which set up the timer
|
||
|
- *
|
||
|
- * When the timer is already registered, then the event counter is
|
||
|
- * incremented. Otherwise the timer is registered in a free slot.
|
||
|
- */
|
||
|
-void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
|
||
|
- void *timerf, char *comm,
|
||
|
- unsigned int timer_flag)
|
||
|
-{
|
||
|
- /*
|
||
|
- * It doesn't matter which lock we take:
|
||
|
- */
|
||
|
- raw_spinlock_t *lock;
|
||
|
- struct entry *entry, input;
|
||
|
- unsigned long flags;
|
||
|
-
|
||
|
- if (likely(!timer_stats_active))
|
||
|
- return;
|
||
|
-
|
||
|
- lock = &per_cpu(tstats_lookup_lock, raw_smp_processor_id());
|
||
|
-
|
||
|
- input.timer = timer;
|
||
|
- input.start_func = startf;
|
||
|
- input.expire_func = timerf;
|
||
|
- input.pid = pid;
|
||
|
- input.timer_flag = timer_flag;
|
||
|
-
|
||
|
- raw_spin_lock_irqsave(lock, flags);
|
||
|
- if (!timer_stats_active)
|
||
|
- goto out_unlock;
|
||
|
-
|
||
|
- entry = tstat_lookup(&input, comm);
|
||
|
- if (likely(entry))
|
||
|
- entry->count++;
|
||
|
- else
|
||
|
- atomic_inc(&overflow_count);
|
||
|
-
|
||
|
- out_unlock:
|
||
|
- raw_spin_unlock_irqrestore(lock, flags);
|
||
|
-}
|
||
|
-
|
||
|
-static void print_name_offset(struct seq_file *m, unsigned long addr)
|
||
|
-{
|
||
|
- char symname[KSYM_NAME_LEN];
|
||
|
-
|
||
|
- if (lookup_symbol_name(addr, symname) < 0)
|
||
|
- seq_printf(m, "<%p>", (void *)addr);
|
||
|
- else
|
||
|
- seq_printf(m, "%s", symname);
|
||
|
-}
|
||
|
-
|
||
|
-static int tstats_show(struct seq_file *m, void *v)
|
||
|
-{
|
||
|
- struct timespec period;
|
||
|
- struct entry *entry;
|
||
|
- unsigned long ms;
|
||
|
- long events = 0;
|
||
|
- ktime_t time;
|
||
|
- int i;
|
||
|
-
|
||
|
- mutex_lock(&show_mutex);
|
||
|
- /*
|
||
|
- * If still active then calculate up to now:
|
||
|
- */
|
||
|
- if (timer_stats_active)
|
||
|
- time_stop = ktime_get();
|
||
|
-
|
||
|
- time = ktime_sub(time_stop, time_start);
|
||
|
-
|
||
|
- period = ktime_to_timespec(time);
|
||
|
- ms = period.tv_nsec / 1000000;
|
||
|
-
|
||
|
- seq_puts(m, "Timer Stats Version: v0.2\n");
|
||
|
- seq_printf(m, "Sample period: %ld.%03ld s\n", period.tv_sec, ms);
|
||
|
- if (atomic_read(&overflow_count))
|
||
|
- seq_printf(m, "Overflow: %d entries\n",
|
||
|
- atomic_read(&overflow_count));
|
||
|
-
|
||
|
- for (i = 0; i < nr_entries; i++) {
|
||
|
- entry = entries + i;
|
||
|
- if (entry->timer_flag & TIMER_STATS_FLAG_DEFERRABLE) {
|
||
|
- seq_printf(m, "%4luD, %5d %-16s ",
|
||
|
- entry->count, entry->pid, entry->comm);
|
||
|
- } else {
|
||
|
- seq_printf(m, " %4lu, %5d %-16s ",
|
||
|
- entry->count, entry->pid, entry->comm);
|
||
|
- }
|
||
|
-
|
||
|
- print_name_offset(m, (unsigned long)entry->start_func);
|
||
|
- seq_puts(m, " (");
|
||
|
- print_name_offset(m, (unsigned long)entry->expire_func);
|
||
|
- seq_puts(m, ")\n");
|
||
|
-
|
||
|
- events += entry->count;
|
||
|
- }
|
||
|
-
|
||
|
- ms += period.tv_sec * 1000;
|
||
|
- if (!ms)
|
||
|
- ms = 1;
|
||
|
-
|
||
|
- if (events && period.tv_sec)
|
||
|
- seq_printf(m, "%ld total events, %ld.%03ld events/sec\n",
|
||
|
- events, events * 1000 / ms,
|
||
|
- (events * 1000000 / ms) % 1000);
|
||
|
- else
|
||
|
- seq_printf(m, "%ld total events\n", events);
|
||
|
-
|
||
|
- mutex_unlock(&show_mutex);
|
||
|
-
|
||
|
- return 0;
|
||
|
-}
|
||
|
-
|
||
|
-/*
|
||
|
- * After a state change, make sure all concurrent lookup/update
|
||
|
- * activities have stopped:
|
||
|
- */
|
||
|
-static void sync_access(void)
|
||
|
-{
|
||
|
- unsigned long flags;
|
||
|
- int cpu;
|
||
|
-
|
||
|
- for_each_online_cpu(cpu) {
|
||
|
- raw_spinlock_t *lock = &per_cpu(tstats_lookup_lock, cpu);
|
||
|
-
|
||
|
- raw_spin_lock_irqsave(lock, flags);
|
||
|
- /* nothing */
|
||
|
- raw_spin_unlock_irqrestore(lock, flags);
|
||
|
- }
|
||
|
-}
|
||
|
-
|
||
|
-static ssize_t tstats_write(struct file *file, const char __user *buf,
|
||
|
- size_t count, loff_t *offs)
|
||
|
-{
|
||
|
- char ctl[2];
|
||
|
-
|
||
|
- if (count != 2 || *offs)
|
||
|
- return -EINVAL;
|
||
|
-
|
||
|
- if (copy_from_user(ctl, buf, count))
|
||
|
- return -EFAULT;
|
||
|
-
|
||
|
- mutex_lock(&show_mutex);
|
||
|
- switch (ctl[0]) {
|
||
|
- case '0':
|
||
|
- if (timer_stats_active) {
|
||
|
- timer_stats_active = 0;
|
||
|
- time_stop = ktime_get();
|
||
|
- sync_access();
|
||
|
- }
|
||
|
- break;
|
||
|
- case '1':
|
||
|
- if (!timer_stats_active) {
|
||
|
- reset_entries();
|
||
|
- time_start = ktime_get();
|
||
|
- smp_mb();
|
||
|
- timer_stats_active = 1;
|
||
|
- }
|
||
|
- break;
|
||
|
- default:
|
||
|
- count = -EINVAL;
|
||
|
- }
|
||
|
- mutex_unlock(&show_mutex);
|
||
|
-
|
||
|
- return count;
|
||
|
-}
|
||
|
-
|
||
|
-static int tstats_open(struct inode *inode, struct file *filp)
|
||
|
-{
|
||
|
- return single_open(filp, tstats_show, NULL);
|
||
|
-}
|
||
|
-
|
||
|
-static const struct file_operations tstats_fops = {
|
||
|
- .open = tstats_open,
|
||
|
- .read = seq_read,
|
||
|
- .write = tstats_write,
|
||
|
- .llseek = seq_lseek,
|
||
|
- .release = single_release,
|
||
|
-};
|
||
|
-
|
||
|
-void __init init_timer_stats(void)
|
||
|
-{
|
||
|
- int cpu;
|
||
|
-
|
||
|
- for_each_possible_cpu(cpu)
|
||
|
- raw_spin_lock_init(&per_cpu(tstats_lookup_lock, cpu));
|
||
|
-}
|
||
|
-
|
||
|
-static int __init init_tstats_procfs(void)
|
||
|
-{
|
||
|
- struct proc_dir_entry *pe;
|
||
|
-
|
||
|
- pe = proc_create("timer_stats", 0644, NULL, &tstats_fops);
|
||
|
- if (!pe)
|
||
|
- return -ENOMEM;
|
||
|
- return 0;
|
||
|
-}
|
||
|
-__initcall(init_tstats_procfs);
|
||
|
diff --git a/kernel/timer.c b/kernel/timer.c
|
||
|
index 5733076..8bff0a9 100644
|
||
|
--- a/kernel/timer.c
|
||
|
+++ b/kernel/timer.c
|
||
|
@@ -397,34 +397,6 @@
|
||
|
}
|
||
|
}
|
||
|
|
||
|
-#ifdef CONFIG_TIMER_STATS
|
||
|
-void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
|
||
|
-{
|
||
|
- if (timer->start_site)
|
||
|
- return;
|
||
|
-
|
||
|
- timer->start_site = addr;
|
||
|
- memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
|
||
|
- timer->start_pid = current->pid;
|
||
|
-}
|
||
|
-
|
||
|
-static void timer_stats_account_timer(struct timer_list *timer)
|
||
|
-{
|
||
|
- unsigned int flag = 0;
|
||
|
-
|
||
|
- if (likely(!timer->start_site))
|
||
|
- return;
|
||
|
- if (unlikely(tbase_get_deferrable(timer->base)))
|
||
|
- flag |= TIMER_STATS_FLAG_DEFERRABLE;
|
||
|
-
|
||
|
- timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
|
||
|
- timer->function, timer->start_comm, flag);
|
||
|
-}
|
||
|
-
|
||
|
-#else
|
||
|
-static void timer_stats_account_timer(struct timer_list *timer) {}
|
||
|
-#endif
|
||
|
-
|
||
|
#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
|
||
|
|
||
|
static struct debug_obj_descr timer_debug_descr;
|
||
|
@@ -637,11 +609,6 @@
|
||
|
timer->entry.next = NULL;
|
||
|
timer->base = (void *)((unsigned long)base | flags);
|
||
|
timer->slack = -1;
|
||
|
-#ifdef CONFIG_TIMER_STATS
|
||
|
- timer->start_site = NULL;
|
||
|
- timer->start_pid = -1;
|
||
|
- memset(timer->start_comm, 0, TASK_COMM_LEN);
|
||
|
-#endif
|
||
|
lockdep_init_map(&timer->lockdep_map, name, key, 0);
|
||
|
}
|
||
|
|
||
|
@@ -739,7 +706,6 @@
|
||
|
unsigned long flags;
|
||
|
int ret = 0 , cpu;
|
||
|
|
||
|
- timer_stats_timer_set_start_info(timer);
|
||
|
BUG_ON(!timer->function);
|
||
|
|
||
|
base = lock_timer_base(timer, &flags);
|
||
|
@@ -943,7 +909,6 @@
|
||
|
struct tvec_base *base = per_cpu(tvec_bases, cpu);
|
||
|
unsigned long flags;
|
||
|
|
||
|
- timer_stats_timer_set_start_info(timer);
|
||
|
BUG_ON(timer_pending(timer) || !timer->function);
|
||
|
spin_lock_irqsave(&base->lock, flags);
|
||
|
timer_set_base(timer, base);
|
||
|
@@ -981,7 +946,6 @@
|
||
|
|
||
|
debug_assert_init(timer);
|
||
|
|
||
|
- timer_stats_timer_clear_start_info(timer);
|
||
|
if (timer_pending(timer)) {
|
||
|
base = lock_timer_base(timer, &flags);
|
||
|
ret = detach_if_pending(timer, base, true);
|
||
|
@@ -1009,10 +973,9 @@
|
||
|
|
||
|
base = lock_timer_base(timer, &flags);
|
||
|
|
||
|
- if (base->running_timer != timer) {
|
||
|
- timer_stats_timer_clear_start_info(timer);
|
||
|
+ if (base->running_timer != timer)
|
||
|
ret = detach_if_pending(timer, base, true);
|
||
|
- }
|
||
|
+
|
||
|
spin_unlock_irqrestore(&base->lock, flags);
|
||
|
|
||
|
return ret;
|
||
|
@@ -1192,8 +1155,6 @@
|
||
|
fn = timer->function;
|
||
|
data = timer->data;
|
||
|
irqsafe = tbase_get_irqsafe(timer->base);
|
||
|
-
|
||
|
- timer_stats_account_timer(timer);
|
||
|
|
||
|
base->running_timer = timer;
|
||
|
detach_expired_timer(timer, base);
|
||
|
@@ -1695,7 +1656,6 @@
|
||
|
|
||
|
err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
|
||
|
(void *)(long)smp_processor_id());
|
||
|
- init_timer_stats();
|
||
|
|
||
|
BUG_ON(err != NOTIFY_OK);
|
||
|
|
||
|
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
|
||
|
index 2505648..562f1a5 100755
|
||
|
--- a/kernel/workqueue.c
|
||
|
+++ b/kernel/workqueue.c
|
||
|
@@ -1448,8 +1448,6 @@
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
- timer_stats_timer_set_start_info(&dwork->timer);
|
||
|
-
|
||
|
dwork->wq = wq;
|
||
|
dwork->cpu = cpu;
|
||
|
timer->expires = jiffies + delay;
|
||
|
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
|
||
|
index a0818f1..822e2be 100755
|
||
|
--- a/lib/Kconfig.debug
|
||
|
+++ b/lib/Kconfig.debug
|
||
|
@@ -400,20 +400,6 @@
|
||
|
application, you can say N to avoid the very slight overhead
|
||
|
this adds.
|
||
|
|
||
|
-config TIMER_STATS
|
||
|
- bool "Collect kernel timers statistics"
|
||
|
- depends on DEBUG_KERNEL && PROC_FS
|
||
|
- help
|
||
|
- If you say Y here, additional code will be inserted into the
|
||
|
- timer routines to collect statistics about kernel timers being
|
||
|
- reprogrammed. The statistics can be read from /proc/timer_stats.
|
||
|
- The statistics collection is started by writing 1 to /proc/timer_stats,
|
||
|
- writing 0 stops it. This feature is useful to collect information
|
||
|
- about timer usage patterns in kernel and userspace. This feature
|
||
|
- is lightweight if enabled in the kernel config but not activated
|
||
|
- (it defaults to deactivated on bootup and will only be activated
|
||
|
- if some application like powertop activates it explicitly).
|
||
|
-
|
||
|
config DEBUG_OBJECTS
|
||
|
bool "Debug object operations"
|
||
|
depends on DEBUG_KERNEL
|