OProfile is enhanced to export all files for controlling System z's hardware sampling, and to invoke hwsampler exported functions to initialize and use System z's hardware sampling. The patch invokes hwsampler_setup() during oprofile init and exports following hwsampler files under oprofilefs if hwsampler's setup succeeded: A new directory for hardware sampling based files /dev/oprofile/hwsampling/ The userland daemon must explicitly write to the following files to disable (or enable) hardware based sampling /dev/oprofile/hwsampling/hwsampler to modify the actual sampling rate /dev/oprofile/hwsampling/hw_interval to modify the amount of sampling memory (measured in 4K pages) /dev/oprofile/hwsampling/hw_sdbt_blocks The following files are read only and show the possible minimum sampling rate /dev/oprofile/hwsampling/hw_min_interval the possible maximum sampling rate /dev/oprofile/hwsampling/hw_max_interval The patch splits the oprofile_timer_[init/exit] function so that it can be also called through user context (oprofilefs) to avoid kernel oops. Applied with following changes: * whitespace changes in Makefile and timer_int.c Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com> Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
306 lines
5.3 KiB
C
306 lines
5.3 KiB
C
/**
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* @file oprof.c
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*
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* @remark Copyright 2002 OProfile authors
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* @remark Read the file COPYING
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*
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* @author John Levon <levon@movementarian.org>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/oprofile.h>
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#include <linux/moduleparam.h>
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#include <linux/workqueue.h>
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#include <linux/time.h>
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#include <asm/mutex.h>
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#include "oprof.h"
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#include "event_buffer.h"
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#include "cpu_buffer.h"
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#include "buffer_sync.h"
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#include "oprofile_stats.h"
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struct oprofile_operations oprofile_ops;
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unsigned long oprofile_started;
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unsigned long oprofile_backtrace_depth;
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static unsigned long is_setup;
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static DEFINE_MUTEX(start_mutex);
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/* timer
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0 - use performance monitoring hardware if available
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1 - use the timer int mechanism regardless
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*/
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static int timer = 0;
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int oprofile_setup(void)
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{
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int err;
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mutex_lock(&start_mutex);
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if ((err = alloc_cpu_buffers()))
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goto out;
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if ((err = alloc_event_buffer()))
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goto out1;
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if (oprofile_ops.setup && (err = oprofile_ops.setup()))
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goto out2;
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/* Note even though this starts part of the
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* profiling overhead, it's necessary to prevent
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* us missing task deaths and eventually oopsing
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* when trying to process the event buffer.
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*/
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if (oprofile_ops.sync_start) {
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int sync_ret = oprofile_ops.sync_start();
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switch (sync_ret) {
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case 0:
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goto post_sync;
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case 1:
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goto do_generic;
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case -1:
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goto out3;
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default:
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goto out3;
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}
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}
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do_generic:
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if ((err = sync_start()))
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goto out3;
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post_sync:
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is_setup = 1;
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mutex_unlock(&start_mutex);
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return 0;
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out3:
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if (oprofile_ops.shutdown)
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oprofile_ops.shutdown();
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out2:
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free_event_buffer();
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out1:
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free_cpu_buffers();
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
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static void switch_worker(struct work_struct *work);
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static DECLARE_DELAYED_WORK(switch_work, switch_worker);
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static void start_switch_worker(void)
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{
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if (oprofile_ops.switch_events)
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schedule_delayed_work(&switch_work, oprofile_time_slice);
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}
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static void stop_switch_worker(void)
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{
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cancel_delayed_work_sync(&switch_work);
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}
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static void switch_worker(struct work_struct *work)
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{
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if (oprofile_ops.switch_events())
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return;
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atomic_inc(&oprofile_stats.multiplex_counter);
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start_switch_worker();
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}
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/* User inputs in ms, converts to jiffies */
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int oprofile_set_timeout(unsigned long val_msec)
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{
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int err = 0;
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unsigned long time_slice;
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mutex_lock(&start_mutex);
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if (oprofile_started) {
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err = -EBUSY;
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goto out;
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}
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if (!oprofile_ops.switch_events) {
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err = -EINVAL;
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goto out;
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}
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time_slice = msecs_to_jiffies(val_msec);
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if (time_slice == MAX_JIFFY_OFFSET) {
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err = -EINVAL;
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goto out;
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}
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oprofile_time_slice = time_slice;
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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#else
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static inline void start_switch_worker(void) { }
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static inline void stop_switch_worker(void) { }
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#endif
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/* Actually start profiling (echo 1>/dev/oprofile/enable) */
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int oprofile_start(void)
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{
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int err = -EINVAL;
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mutex_lock(&start_mutex);
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if (!is_setup)
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goto out;
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err = 0;
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if (oprofile_started)
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goto out;
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oprofile_reset_stats();
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if ((err = oprofile_ops.start()))
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goto out;
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start_switch_worker();
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oprofile_started = 1;
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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/* echo 0>/dev/oprofile/enable */
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void oprofile_stop(void)
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{
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mutex_lock(&start_mutex);
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if (!oprofile_started)
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goto out;
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oprofile_ops.stop();
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oprofile_started = 0;
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stop_switch_worker();
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/* wake up the daemon to read what remains */
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wake_up_buffer_waiter();
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out:
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mutex_unlock(&start_mutex);
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}
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void oprofile_shutdown(void)
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{
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mutex_lock(&start_mutex);
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if (oprofile_ops.sync_stop) {
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int sync_ret = oprofile_ops.sync_stop();
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switch (sync_ret) {
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case 0:
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goto post_sync;
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case 1:
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goto do_generic;
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default:
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goto post_sync;
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}
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}
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do_generic:
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sync_stop();
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post_sync:
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if (oprofile_ops.shutdown)
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oprofile_ops.shutdown();
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is_setup = 0;
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free_event_buffer();
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free_cpu_buffers();
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mutex_unlock(&start_mutex);
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}
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int oprofile_set_ulong(unsigned long *addr, unsigned long val)
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{
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int err = -EBUSY;
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mutex_lock(&start_mutex);
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if (!oprofile_started) {
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*addr = val;
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err = 0;
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}
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mutex_unlock(&start_mutex);
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return err;
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}
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#ifdef CONFIG_HAVE_HWSAMPLER
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int oprofile_set_hwsampler(unsigned long val)
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{
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int err = 0;
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mutex_lock(&start_mutex);
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if (oprofile_started) {
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err = -EBUSY;
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goto out;
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}
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switch (val) {
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case 1:
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/* Switch to hardware sampling. */
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__oprofile_timer_exit();
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err = oprofile_arch_set_hwsampler(&oprofile_ops);
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break;
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case 0:
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printk(KERN_INFO "oprofile: using timer interrupt.\n");
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err = __oprofile_timer_init(&oprofile_ops);
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break;
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default:
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err = -EINVAL;
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}
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out:
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mutex_unlock(&start_mutex);
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return err;
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}
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#endif /* CONFIG_HAVE_HWSAMPLER */
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static int __init oprofile_init(void)
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{
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int err;
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err = oprofile_arch_init(&oprofile_ops);
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if (err < 0 || timer) {
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printk(KERN_INFO "oprofile: using timer interrupt.\n");
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err = oprofile_timer_init(&oprofile_ops);
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if (err)
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return err;
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}
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return oprofilefs_register();
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}
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static void __exit oprofile_exit(void)
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{
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oprofile_timer_exit();
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oprofilefs_unregister();
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oprofile_arch_exit();
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}
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module_init(oprofile_init);
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module_exit(oprofile_exit);
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module_param_named(timer, timer, int, 0644);
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MODULE_PARM_DESC(timer, "force use of timer interrupt");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("John Levon <levon@movementarian.org>");
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MODULE_DESCRIPTION("OProfile system profiler");
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