From 1a960b402a51d80abf54e3f8e4972374ffe5f22d Mon Sep 17 00:00:00 2001 From: Jason Yeh Date: Wed, 23 Jul 2008 23:05:53 +0200 Subject: Oprofile Multiplexing Patch This patch introduces multiplexing support for the Oprofile kernel module. It basically adds a new function pointer in oprofile_operator allowing each architecture to supply its callback to switch between different sets of event when the timer expires. Userspace tools can modify the time slice through /dev/oprofile/time_slice. It also modifies the number of counters exposed to the userspace through /dev/oprofile. For example, the number of counters for AMD CPUs are changed to 32 and multiplexed in the sets of 4. Signed-off-by: Jason Yeh Signed-off-by: Robert Richter Cc: oprofile-list Signed-off-by: Ingo Molnar --- drivers/oprofile/oprof.c | 58 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 3 deletions(-) (limited to 'drivers/oprofile/oprof.c') diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c index 2c645170f06..b2fa5df64a6 100644 --- a/drivers/oprofile/oprof.c +++ b/drivers/oprofile/oprof.c @@ -12,6 +12,8 @@ #include #include #include +#include +#include #include #include "oprof.h" @@ -19,13 +21,18 @@ #include "cpu_buffer.h" #include "buffer_sync.h" #include "oprofile_stats.h" + +static unsigned long is_setup; +static void switch_worker(struct work_struct *work); +static DECLARE_DELAYED_WORK(switch_work, switch_worker); +static DEFINE_MUTEX(start_mutex); struct oprofile_operations oprofile_ops; +unsigned long timeout_jiffies; unsigned long oprofile_started; unsigned long backtrace_depth; -static unsigned long is_setup; -static DEFINE_MUTEX(start_mutex); +/* Multiplexing defaults at 1 msec*/ /* timer 0 - use performance monitoring hardware if available @@ -87,6 +94,16 @@ out: return err; } +static void start_switch_worker(void) +{ + schedule_delayed_work(&switch_work, timeout_jiffies); +} + +static void switch_worker(struct work_struct *work) +{ + if (!oprofile_ops.switch_events()) + start_switch_worker(); +} /* Actually start profiling (echo 1>/dev/oprofile/enable) */ int oprofile_start(void) @@ -94,7 +111,6 @@ int oprofile_start(void) int err = -EINVAL; mutex_lock(&start_mutex); - if (!is_setup) goto out; @@ -108,6 +124,9 @@ int oprofile_start(void) if ((err = oprofile_ops.start())) goto out; + if (oprofile_ops.switch_events) + start_switch_worker(); + oprofile_started = 1; out: mutex_unlock(&start_mutex); @@ -123,6 +142,7 @@ void oprofile_stop(void) goto out; oprofile_ops.stop(); oprofile_started = 0; + cancel_delayed_work_sync(&switch_work); /* wake up the daemon to read what remains */ wake_up_buffer_waiter(); out: @@ -155,6 +175,32 @@ post_sync: mutex_unlock(&start_mutex); } +/* User inputs in ms, converts to jiffies */ +int oprofile_set_timeout(unsigned long val_msec) +{ + int err = 0; + + mutex_lock(&start_mutex); + + if (oprofile_started) { + err = -EBUSY; + goto out; + } + + if (!oprofile_ops.switch_events) { + err = -EINVAL; + goto out; + } + + timeout_jiffies = msecs_to_jiffies(val_msec); + if (timeout_jiffies == MAX_JIFFY_OFFSET) + timeout_jiffies = msecs_to_jiffies(1); + +out: + mutex_unlock(&start_mutex); + return err; + +} int oprofile_set_backtrace(unsigned long val) { @@ -179,10 +225,16 @@ out: return err; } +static void __init oprofile_switch_timer_init(void) +{ + timeout_jiffies = msecs_to_jiffies(1); +} + static int __init oprofile_init(void) { int err; + oprofile_switch_timer_init(); err = oprofile_arch_init(&oprofile_ops); if (err < 0 || timer) { -- cgit v1.2.3