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 +++++++++++++++++++++++++++++++++++++-- drivers/oprofile/oprof.h | 4 ++- drivers/oprofile/oprofile_files.c | 39 ++++++++++++++++++++++++-- 3 files changed, 95 insertions(+), 6 deletions(-) (limited to 'drivers/oprofile') 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) { diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h index 18323650806..c4406a7366b 100644 --- a/drivers/oprofile/oprof.h +++ b/drivers/oprofile/oprof.h @@ -27,7 +27,8 @@ extern unsigned long fs_buffer_watershed; extern struct oprofile_operations oprofile_ops; extern unsigned long oprofile_started; extern unsigned long backtrace_depth; - +extern unsigned long timeout_jiffies; + struct super_block; struct dentry; @@ -35,5 +36,6 @@ void oprofile_create_files(struct super_block * sb, struct dentry * root); void oprofile_timer_init(struct oprofile_operations * ops); int oprofile_set_backtrace(unsigned long depth); +int oprofile_set_timeout(unsigned long time); #endif /* OPROF_H */ diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c index ef953ba5ab6..cc4f5a1f8ef 100644 --- a/drivers/oprofile/oprofile_files.c +++ b/drivers/oprofile/oprofile_files.c @@ -9,6 +9,7 @@ #include #include +#include #include "event_buffer.h" #include "oprofile_stats.h" @@ -18,6 +19,40 @@ unsigned long fs_buffer_size = 131072; unsigned long fs_cpu_buffer_size = 8192; unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */ +static ssize_t timeout_read(struct file *file, char __user *buf, + size_t count, loff_t *offset) +{ + return oprofilefs_ulong_to_user(jiffies_to_msecs(timeout_jiffies), + buf, count, offset); +} + + +static ssize_t timeout_write(struct file *file, char const __user *buf, + size_t count, loff_t *offset) +{ + unsigned long val; + int retval; + + if (*offset) + return -EINVAL; + + retval = oprofilefs_ulong_from_user(&val, buf, count); + if (retval) + return retval; + + retval = oprofile_set_timeout(val); + + if (retval) + return retval; + return count; +} + +static const struct file_operations timeout_fops = { + .read = timeout_read, + .write = timeout_write, +}; + + static ssize_t depth_read(struct file * file, char __user * buf, size_t count, loff_t * offset) { return oprofilefs_ulong_to_user(backtrace_depth, buf, count, offset); @@ -85,11 +120,10 @@ static ssize_t enable_write(struct file * file, char const __user * buf, size_t if (*offset) return -EINVAL; - retval = oprofilefs_ulong_from_user(&val, buf, count); if (retval) return retval; - + if (val) retval = oprofile_start(); else @@ -129,6 +163,7 @@ void oprofile_create_files(struct super_block * sb, struct dentry * root) oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops); oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops); oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops); + oprofilefs_create_file(sb, root, "timeout_ms", &timeout_fops); oprofile_create_stats_files(sb, root); if (oprofile_ops.create_files) oprofile_ops.create_files(sb, root); -- cgit v1.2.3