delta patch - s390 hw sampling rework on comments as of Feb 14th

Index: s390/drivers/oprofile/cpu_buffer.c
===================================================================
@@ -1,12 +1,13 @@
 /**
  * @file cpu_buffer.c
  *
- * @remark Copyright 2002-2009 OProfile authors
+ * @remark Copyright 2002-2011 OProfile authors
  * @remark Read the file COPYING
  *
  * @author John Levon <[email protected]>
  * @author Barry Kasindorf <[email protected]>
  * @author Robert Richter <[email protected]>
+ * @author Heinz Graalfs <[email protected]>
  *
  * Each CPU has a local buffer that stores PC value/event
  * pairs. We also log context switches when we notice them.

@@ -179,8 +180,8 @@ unsigned long op_cpu_buffer_entries(int
 }
 
 static int
-op_add_code(struct oprofile_cpu_buffer *cpu_buf, unsigned long backtrace,
-	    int is_kernel, struct task_struct *task)
+op_add_code(struct oprofile_cpu_buffer *cpu_buf,
+		    struct oprofile_sample_parms *parms)
 {
 	struct op_entry entry;
 	struct op_sample *sample;

@@ -189,21 +190,21 @@ op_add_code(struct oprofile_cpu_buffer *
 
 	flags = 0;
 
-	if (backtrace)
+	if (parms->backtrace)
 		flags |= TRACE_BEGIN;
 
 	/* notice a switch from user->kernel or vice versa */
-	is_kernel = !!is_kernel;
-	if (cpu_buf->last_is_kernel != is_kernel) {
-		cpu_buf->last_is_kernel = is_kernel;
+	parms->is_kernel = !!parms->is_kernel;
+	if (cpu_buf->last_is_kernel != parms->is_kernel) {
+		cpu_buf->last_is_kernel = parms->is_kernel;
 		flags |= KERNEL_CTX_SWITCH;
-		if (is_kernel)
+		if (parms->is_kernel)
 			flags |= IS_KERNEL;
 	}
 
 	/* notice a task switch */
-	if (cpu_buf->last_task != task) {
-		cpu_buf->last_task = task;
+	if (cpu_buf->last_task != parms->task) {
+		cpu_buf->last_task = parms->task;
 		flags |= USER_CTX_SWITCH;
 	}
 

@@ -224,7 +225,7 @@ op_add_code(struct oprofile_cpu_buffer *
 	sample->event = flags;
 
 	if (size)
-		op_cpu_buffer_add_data(&entry, (unsigned long)task);
+		op_cpu_buffer_add_data(&entry, (unsigned long)parms->task);
 
 	op_cpu_buffer_write_commit(&entry);
 

@@ -233,7 +234,7 @@ op_add_code(struct oprofile_cpu_buffer *
 
 static inline int
 op_add_sample(struct oprofile_cpu_buffer *cpu_buf,
-	      unsigned long pc, unsigned long event)
+		      struct oprofile_sample_parms *parms)
 {
 	struct op_entry entry;
 	struct op_sample *sample;

@@ -242,8 +243,8 @@ op_add_sample(struct oprofile_cpu_buffer
 	if (!sample)
 		return -ENOMEM;
 
-	sample->eip = pc;
-	sample->event = event;
+	sample->eip = parms->pc;
+	sample->event = parms->event;
 
 	return op_cpu_buffer_write_commit(&entry);
 }

@@ -256,23 +257,23 @@ op_add_sample(struct oprofile_cpu_buffer
  * pc. We tag this in the buffer by generating kernel enter/exit
  * events whenever is_kernel changes
  */
+
 static int
-log_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc,
-	   unsigned long backtrace, int is_kernel, unsigned long event,
-	   struct task_struct *task)
+log_sample(struct oprofile_cpu_buffer *cpu_buf,
+	   struct oprofile_sample_parms *parms)
 {
-	struct task_struct *tsk = task ? task : current;
+	parms->task = parms->task ? parms->task : current;
 	cpu_buf->sample_received++;
 
-	if (pc == ESCAPE_CODE) {
+	if (parms->pc == ESCAPE_CODE) {
 		cpu_buf->sample_invalid_eip++;
 		return 0;
 	}
 
-	if (op_add_code(cpu_buf, backtrace, is_kernel, tsk))
+	if (op_add_code(cpu_buf, parms))
 		goto fail;
 
-	if (op_add_sample(cpu_buf, pc, event))
+	if (op_add_sample(cpu_buf, parms))
 		goto fail;
 
 	return 1;

@@ -293,26 +294,24 @@ static inline void oprofile_end_trace(st
 }
 
 static inline void
-__oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
-			  unsigned long event, int is_kernel,
-			  struct task_struct *task)
+__oprofile_add_ext_sample(struct oprofile_sample_parms *parms)
 {
 	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
-	unsigned long backtrace = oprofile_backtrace_depth;
+	parms->backtrace = oprofile_backtrace_depth;
 
 	/*
 	 * if log_sample() fail we can't backtrace since we lost the
 	 * source of this event
 	 */
-	if (!log_sample(cpu_buf, pc, backtrace, is_kernel, event, task))
+	if (!log_sample(cpu_buf, parms))
 		/* failed */
 		return;
 
-	if (!backtrace)
+	if (!parms->backtrace)
 		return;
 
 	oprofile_begin_trace(cpu_buf);
-	oprofile_ops.backtrace(regs, backtrace);
+	oprofile_ops.backtrace(parms->regs, parms->backtrace);
 	oprofile_end_trace(cpu_buf);
 }
 

@@ -320,29 +319,41 @@ void oprofile_add_ext_hw_sample(unsigned
 				unsigned long event, int is_kernel,
 				struct task_struct *task)
 {
-	__oprofile_add_ext_sample(pc, regs, event, is_kernel, task);
+	struct oprofile_sample_parms parms = {
+		.pc = pc, .backtrace = 0, .event = event,
+		.is_kernel = is_kernel, .regs = regs,
+		.task = task ? task : current
+	};
+
+	__oprofile_add_ext_sample(&parms);
 }
 
 void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
 			     unsigned long event, int is_kernel)
 {
-	__oprofile_add_ext_sample(pc, regs, event, is_kernel, NULL);
+	struct oprofile_sample_parms parms = {
+		.pc = pc, .backtrace = 0, .event = event,
+		.is_kernel = is_kernel, .regs = regs, .task = NULL
+	};
+	__oprofile_add_ext_sample(&parms);
 }
 
 void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
 {
-	int is_kernel;
-	unsigned long pc;
+	struct oprofile_sample_parms parms = {
+		.pc = 0, .backtrace = 0, .event = event,
+		.is_kernel = 0, .regs = regs, .task = NULL
+	};
 
 	if (likely(regs)) {
-		is_kernel = !user_mode(regs);
-		pc = profile_pc(regs);
+		parms.is_kernel = !user_mode(regs);
+		parms.pc = profile_pc(regs);
 	} else {
-		is_kernel = 0;    /* This value will not be used */
-		pc = ESCAPE_CODE; /* as this causes an early return. */
+		parms.is_kernel = 0;    /* This value will not be used */
+		parms.pc = ESCAPE_CODE; /* as this causes an early return. */
 	}
 
-	__oprofile_add_ext_sample(pc, regs, event, is_kernel, NULL);
+	__oprofile_add_ext_sample(&parms);
 }
 
 /*

@@ -356,13 +367,17 @@ oprofile_write_reserve(struct op_entry *
 		       unsigned long pc, int code, int size)
 {
 	struct op_sample *sample;
-	int is_kernel = !user_mode(regs);
 	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_sample_parms parms = {
+		.pc = pc, .backtrace = 0, .event = 0,
+		.is_kernel = !user_mode(regs), .task = current,
+		.regs = regs
+	};
 
 	cpu_buf->sample_received++;
 
 	/* no backtraces for samples with data */
-	if (op_add_code(cpu_buf, 0, is_kernel, current))
+	if (op_add_code(cpu_buf, &parms))
 		goto fail;
 
 	sample = op_cpu_buffer_write_reserve(entry, size + 2);

@@ -413,12 +428,20 @@ int oprofile_write_commit(struct op_entr
 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event)
 {
 	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
-	log_sample(cpu_buf, pc, 0, is_kernel, event, NULL);
+	struct oprofile_sample_parms parms = {
+		.pc = pc, .backtrace = 0, .event = event,
+		.is_kernel = is_kernel, .task = NULL, .regs = NULL
+	};
+	log_sample(cpu_buf, &parms);
 }
 
 void oprofile_add_trace(unsigned long pc)
 {
 	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_sample_parms parms = {
+		.pc = pc, .backtrace = 0, .event = 0,
+		.is_kernel = 0, .task = NULL, .regs = NULL
+	};
 
 	if (!cpu_buf->tracing)
 		return;

@@ -430,7 +453,7 @@ void oprofile_add_trace(unsigned long pc
 	if (pc == ESCAPE_CODE)
 		goto fail;
 
-	if (op_add_sample(cpu_buf, pc, 0))
+	if (op_add_sample(cpu_buf, &parms))
 		goto fail;
 
 	return;

Index: s390/drivers/oprofile/cpu_buffer.h
===================================================================
@@ -51,6 +51,15 @@ struct oprofile_cpu_buffer {
 	struct delayed_work work;
 };
 
+struct oprofile_sample_parms {
+	int is_kernel;
+	unsigned long pc;
+	unsigned long backtrace;
+	unsigned long event;
+	struct task_struct *task;
+	struct pt_regs *regs;
+};
+
 DECLARE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);
 
 /*

Index: s390/arch/s390/oprofile/init.c
===================================================================
@@ -4,19 +4,174 @@
  * S390 Version
  *   Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
  *   Author(s): Thomas Spatzier ([email protected])
+ *   Author(s): Mahesh Salgaonkar ([email protected])
+ *   Author(s): Heinz Graalfs ([email protected])
  *
- * @remark Copyright 2002 OProfile authors
+ * @remark Copyright 2002-2011 OProfile authors
  */
 
 #include <linux/oprofile.h>
 #include <linux/init.h>
 #include <linux/errno.h>
+#include <linux/oprofile.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+
+#include "../../../drivers/oprofile/oprof.h"
+#include "hwsampler.h"
+
+#define DEFAULT_INTERVAL	4096
+
+#define DEFAULT_SDBT_BLOCKS	1
+#define DEFAULT_SDB_BLOCKS	511
+
+static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
+static unsigned long oprofile_min_interval;
+static unsigned long oprofile_max_interval;
 
-extern int oprofile_hwsampler_init(struct oprofile_operations* ops);
-extern void oprofile_hwsampler_exit(void);
+static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
+static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
+
+static int hwsampler_file;
+static int hwsampler_running;	/* start_mutex must be held to change */
+
+static struct oprofile_operations timer_ops;
 
 extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
 
+static int oprofile_hwsampler_start(void)
+{
+	int retval;
+
+	hwsampler_running = hwsampler_file;
+
+	if (!hwsampler_running)
+		return timer_ops.start();
+
+	retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
+	if (retval)
+		return retval;
+
+	retval = hwsampler_start_all(oprofile_hw_interval);
+	if (retval)
+		hwsampler_deallocate();
+
+	return retval;
+}
+
+static void oprofile_hwsampler_stop(void)
+{
+	if (!hwsampler_running) {
+		timer_ops.stop();
+		return;
+	}
+
+	hwsampler_stop_all();
+	hwsampler_deallocate();
+	return;
+}
+
+static ssize_t hwsampler_read(struct file *file, char __user *buf,
+		size_t count, loff_t *offset)
+{
+	return oprofilefs_ulong_to_user(hwsampler_file, buf, count, offset);
+}
+
+static ssize_t hwsampler_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;
+
+	if (oprofile_started)
+		/*
+		 * save to do without locking as we set
+		 * hwsampler_running in start() when start_mutex is
+		 * held
+		 */
+		return -EBUSY;
+
+	hwsampler_file = val;
+
+	return count;
+}
+
+static const struct file_operations hwsampler_fops = {
+	.read		= hwsampler_read,
+	.write		= hwsampler_write,
+};
+
+static int oprofile_create_hwsampling_files(struct super_block *sb,
+						struct dentry *root)
+{
+	struct dentry *hw_dir;
+
+	/* reinitialize default values */
+	hwsampler_file = 1;
+
+	hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");
+	if (!hw_dir)
+		return -EINVAL;
+
+	oprofilefs_create_file(sb, hw_dir, "hwsampler", &hwsampler_fops);
+	oprofilefs_create_ulong(sb, hw_dir, "hw_interval",
+				&oprofile_hw_interval);
+	oprofilefs_create_ro_ulong(sb, hw_dir, "hw_min_interval",
+				&oprofile_min_interval);
+	oprofilefs_create_ro_ulong(sb, hw_dir, "hw_max_interval",
+				&oprofile_max_interval);
+	oprofilefs_create_ulong(sb, hw_dir, "hw_sdbt_blocks",
+				&oprofile_sdbt_blocks);
+
+	return 0;
+}
+
+int oprofile_hwsampler_init(struct oprofile_operations* ops)
+{
+	if (hwsampler_setup())
+		return -ENODEV;
+
+	/*
+	 * create hwsampler files only if hwsampler_setup() succeeds.
+	 */
+	oprofile_min_interval = hwsampler_query_min_interval();
+	if (oprofile_min_interval < 0) {
+		oprofile_min_interval = 0;
+		return -ENODEV;
+	}
+	oprofile_max_interval = hwsampler_query_max_interval();
+	if (oprofile_max_interval < 0) {
+		oprofile_max_interval = 0;
+		return -ENODEV;
+	}
+
+	if (oprofile_timer_init(ops))
+		return -ENODEV;
+
+	printk(KERN_INFO "oprofile: using hardware sampling\n");
+
+	memcpy(&timer_ops, ops, sizeof(timer_ops));
+
+	ops->start = oprofile_hwsampler_start;
+	ops->stop = oprofile_hwsampler_stop;
+	ops->create_files = oprofile_create_hwsampling_files;
+
+	return 0;
+}
+
+void oprofile_hwsampler_exit(void)
+{
+	oprofile_timer_exit();
+	hwsampler_shutdown();
+}
+
 int __init oprofile_arch_init(struct oprofile_operations* ops)
 {
 	ops->backtrace = s390_backtrace;

162 lines not on this page · raw message