[Cbe-oss-dev] [PATCH, RFC] sputrace: use the generic event tracer

Christoph Hellwig hch at lst.de
Sat Jun 13 00:31:52 EST 2009


[reposted, only change to the RFC a while ago is the field ordering in
 the binary trace record.  Now that all prerequisites are in it applies
 against mainline]


I wrote sputrace before generic tracing infrastrucure was available.
Now that we have the generic event tracer we can convert it over and
remove a lot of code:

  8 files changed, 45 insertions(+), 285 deletions(-)

To use it make sure CONFIG_EVENT_TRACING is enabled and then enable
the spufs trace channel by

  echo 1 > /sys/kernel/debug/tracing/events/spufs/spufs_context

and then read the trace records using e.g.

  cat /sys/kernel/debug/tracing/trace


I don't have any cell hardware anymore so this is only compile tested.


Signed-off-by: Christoph Hellwig <hch at lst.de>


Index: linux-2.6/arch/powerpc/platforms/cell/spufs/sputrace.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/sputrace.h	2009-06-12 16:29:21.295817428 +0200
@@ -0,0 +1,39 @@
+#if !defined(_TRACE_SPUFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SPUFS_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM spufs
+
+TRACE_EVENT(spufs_context,
+	TP_PROTO(struct spu_context *ctx, struct spu *spu, const char *name),
+	TP_ARGS(ctx, spu, name),
+
+	TP_STRUCT__entry(
+		__field(const char *, name)
+		__field(int, owner_tid)
+		__field(int, number)
+	),
+
+	TP_fast_assign(
+		__entry->name = name;
+		__entry->owner_tid = ctx->tid;
+		__entry->number = spu ? spu->number : -1;
+	),
+
+	TP_printk("%s (ctxthread = %d, spu = %d)",
+		__entry->name, __entry->owner_tid, __entry->number)
+);
+
+#define spu_context_trace(name, ctx, spu) \
+	trace_spufs_context(ctx, spu, __stringify(name))
+#define spu_context_nospu_trace(name, ctx) \
+	trace_spufs_context(ctx, NULL, __stringify(name))
+
+#endif /* _TRACE_SPUFS_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE sputrace
+#include <trace/define_trace.h>
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/spufs.h	2009-05-14 18:52:09.661784824 +0200
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h	2009-06-12 16:25:33.796969757 +0200
@@ -373,9 +373,4 @@ extern void spu_free_lscsa(struct spu_st
 extern void spuctx_switch_state(struct spu_context *ctx,
 		enum spu_utilization_state new_state);
 
-#define spu_context_trace(name, ctx, spu) \
-	trace_mark(name, "ctx %p spu %p", ctx, spu);
-#define spu_context_nospu_trace(name, ctx) \
-	trace_mark(name, "ctx %p", ctx);
-
 #endif
Index: linux-2.6/arch/powerpc/platforms/cell/Kconfig
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/Kconfig	2009-05-14 18:52:09.413784729 +0200
+++ linux-2.6/arch/powerpc/platforms/cell/Kconfig	2009-06-12 16:25:33.797967580 +0200
@@ -80,13 +80,6 @@ config SPU_FS_64K_LS
 	  uses 4K pages. This can improve performances of applications
 	  using multiple SPEs by lowering the TLB pressure on them.
 
-config SPU_TRACE
-	tristate "SPU event tracing support"
-	depends on SPU_FS && MARKERS
-	help
-	  This option allows reading a trace of spu-related events through
-	  the sputrace file in procfs.
-
 config SPU_BASE
 	bool
 	default n
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/Makefile
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/Makefile	2009-05-14 18:52:09.608784652 +0200
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/Makefile	2009-06-12 16:25:33.797967580 +0200
@@ -4,7 +4,8 @@ spufs-y += inode.o file.o context.o sysc
 spufs-y += sched.o backing_ops.o hw_ops.o run.o gang.o
 spufs-y += switch.o fault.o lscsa_alloc.o
 
-obj-$(CONFIG_SPU_TRACE)	+= sputrace.o
+# magic for the trace events
+CFLAGS_sched.o := -I$(src)
 
 # Rules to build switch.o with the help of SPU tool chain
 SPU_CROSS	:= spu-
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/sputrace.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/sputrace.c	2009-05-14 18:52:09.663784799 +0200
+++ /dev/null	1970-01-01 00:00:00.000000000 +0000
@@ -1,272 +0,0 @@
-/*
- * Copyright (C) 2007 IBM Deutschland Entwicklung GmbH
- *	Released under GPL v2.
- *
- * Partially based on net/ipv4/tcp_probe.c.
- *
- * Simple tracing facility for spu contexts.
- */
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/marker.h>
-#include <linux/proc_fs.h>
-#include <linux/wait.h>
-#include <asm/atomic.h>
-#include <asm/uaccess.h>
-#include "spufs.h"
-
-struct spu_probe {
-	const char *name;
-	const char *format;
-	marker_probe_func *probe_func;
-};
-
-struct sputrace {
-	ktime_t tstamp;
-	int owner_tid; /* owner */
-	int curr_tid;
-	const char *name;
-	int number;
-};
-
-static int bufsize __read_mostly = 16384;
-MODULE_PARM_DESC(bufsize, "Log buffer size (number of records)");
-module_param(bufsize, int, 0);
-
-
-static DEFINE_SPINLOCK(sputrace_lock);
-static DECLARE_WAIT_QUEUE_HEAD(sputrace_wait);
-static ktime_t sputrace_start;
-static unsigned long sputrace_head, sputrace_tail;
-static struct sputrace *sputrace_log;
-static int sputrace_logging;
-
-static int sputrace_used(void)
-{
-	return (sputrace_head - sputrace_tail) % bufsize;
-}
-
-static inline int sputrace_avail(void)
-{
-	return bufsize - sputrace_used();
-}
-
-static int sputrace_sprint(char *tbuf, int n)
-{
-	const struct sputrace *t = sputrace_log + sputrace_tail % bufsize;
-	struct timespec tv =
-		ktime_to_timespec(ktime_sub(t->tstamp, sputrace_start));
-
-	return snprintf(tbuf, n,
-		"[%lu.%09lu] %d: %s (ctxthread = %d, spu = %d)\n",
-		(unsigned long) tv.tv_sec,
-		(unsigned long) tv.tv_nsec,
-		t->curr_tid,
-		t->name,
-		t->owner_tid,
-		t->number);
-}
-
-static ssize_t sputrace_read(struct file *file, char __user *buf,
-		size_t len, loff_t *ppos)
-{
-	int error = 0, cnt = 0;
-
-	if (!buf || len < 0)
-		return -EINVAL;
-
-	while (cnt < len) {
-		char tbuf[128];
-		int width;
-
-		/* If we have data ready to return, don't block waiting
-		 * for more */
-		if (cnt > 0 && sputrace_used() == 0)
-			break;
-
-		error = wait_event_interruptible(sputrace_wait,
-						 sputrace_used() > 0);
-		if (error)
-			break;
-
-		spin_lock(&sputrace_lock);
-		if (sputrace_head == sputrace_tail) {
-			spin_unlock(&sputrace_lock);
-			continue;
-		}
-
-		width = sputrace_sprint(tbuf, sizeof(tbuf));
-		if (width < len)
-			sputrace_tail = (sputrace_tail + 1) % bufsize;
-		spin_unlock(&sputrace_lock);
-
-		if (width >= len)
-			break;
-
-		error = copy_to_user(buf + cnt, tbuf, width);
-		if (error)
-			break;
-		cnt += width;
-	}
-
-	return cnt == 0 ? error : cnt;
-}
-
-static int sputrace_open(struct inode *inode, struct file *file)
-{
-	int rc;
-
-	spin_lock(&sputrace_lock);
-	if (sputrace_logging) {
-		rc = -EBUSY;
-		goto out;
-	}
-
-	sputrace_logging = 1;
-	sputrace_head = sputrace_tail = 0;
-	sputrace_start = ktime_get();
-	rc = 0;
-
-out:
-	spin_unlock(&sputrace_lock);
-	return rc;
-}
-
-static int sputrace_release(struct inode *inode, struct file *file)
-{
-	spin_lock(&sputrace_lock);
-	sputrace_logging = 0;
-	spin_unlock(&sputrace_lock);
-	return 0;
-}
-
-static const struct file_operations sputrace_fops = {
-	.owner   = THIS_MODULE,
-	.open    = sputrace_open,
-	.read    = sputrace_read,
-	.release = sputrace_release,
-};
-
-static void sputrace_log_item(const char *name, struct spu_context *ctx,
-		struct spu *spu)
-{
-	spin_lock(&sputrace_lock);
-
-	if (!sputrace_logging) {
-		spin_unlock(&sputrace_lock);
-		return;
-	}
-
-	if (sputrace_avail() > 1) {
-		struct sputrace *t = sputrace_log + sputrace_head;
-
-		t->tstamp = ktime_get();
-		t->owner_tid = ctx->tid;
-		t->name = name;
-		t->curr_tid = current->pid;
-		t->number = spu ? spu->number : -1;
-
-		sputrace_head = (sputrace_head + 1) % bufsize;
-	} else {
-		printk(KERN_WARNING
-		       "sputrace: lost samples due to full buffer.\n");
-	}
-	spin_unlock(&sputrace_lock);
-
-	wake_up(&sputrace_wait);
-}
-
-static void spu_context_event(void *probe_private, void *call_data,
-		const char *format, va_list *args)
-{
-	struct spu_probe *p = probe_private;
-	struct spu_context *ctx;
-	struct spu *spu;
-
-	ctx = va_arg(*args, struct spu_context *);
-	spu = va_arg(*args, struct spu *);
-
-	sputrace_log_item(p->name, ctx, spu);
-}
-
-static void spu_context_nospu_event(void *probe_private, void *call_data,
-		const char *format, va_list *args)
-{
-	struct spu_probe *p = probe_private;
-	struct spu_context *ctx;
-
-	ctx = va_arg(*args, struct spu_context *);
-
-	sputrace_log_item(p->name, ctx, NULL);
-}
-
-struct spu_probe spu_probes[] = {
-	{ "spu_bind_context__enter", "ctx %p spu %p", spu_context_event },
-	{ "spu_unbind_context__enter", "ctx %p spu %p", spu_context_event },
-	{ "spu_get_idle__enter", "ctx %p", spu_context_nospu_event },
-	{ "spu_get_idle__found", "ctx %p spu %p", spu_context_event },
-	{ "spu_get_idle__not_found", "ctx %p", spu_context_nospu_event },
-	{ "spu_find_victim__enter", "ctx %p", spu_context_nospu_event },
-	{ "spusched_tick__preempt", "ctx %p spu %p", spu_context_event },
-	{ "spusched_tick__newslice", "ctx %p", spu_context_nospu_event },
-	{ "spu_yield__enter", "ctx %p", spu_context_nospu_event },
-	{ "spu_deactivate__enter", "ctx %p", spu_context_nospu_event },
-	{ "__spu_deactivate__unload", "ctx %p spu %p", spu_context_event },
-	{ "spufs_ps_fault__enter", "ctx %p", spu_context_nospu_event },
-	{ "spufs_ps_fault__sleep", "ctx %p", spu_context_nospu_event },
-	{ "spufs_ps_fault__wake", "ctx %p spu %p", spu_context_event },
-	{ "spufs_ps_fault__insert", "ctx %p spu %p", spu_context_event },
-	{ "spu_acquire_saved__enter", "ctx %p", spu_context_nospu_event },
-	{ "destroy_spu_context__enter", "ctx %p", spu_context_nospu_event },
-	{ "spufs_stop_callback__enter", "ctx %p spu %p", spu_context_event },
-};
-
-static int __init sputrace_init(void)
-{
-	struct proc_dir_entry *entry;
-	int i, error = -ENOMEM;
-
-	sputrace_log = kcalloc(bufsize, sizeof(struct sputrace), GFP_KERNEL);
-	if (!sputrace_log)
-		goto out;
-
-	entry = proc_create("sputrace", S_IRUSR, NULL, &sputrace_fops);
-	if (!entry)
-		goto out_free_log;
-
-	for (i = 0; i < ARRAY_SIZE(spu_probes); i++) {
-		struct spu_probe *p = &spu_probes[i];
-
-		error = marker_probe_register(p->name, p->format,
-					      p->probe_func, p);
-		if (error)
-			printk(KERN_INFO "Unable to register probe %s\n",
-					p->name);
-	}
-
-	return 0;
-
-out_free_log:
-	kfree(sputrace_log);
-out:
-	return -ENOMEM;
-}
-
-static void __exit sputrace_exit(void)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(spu_probes); i++)
-		marker_probe_unregister(spu_probes[i].name,
-			spu_probes[i].probe_func, &spu_probes[i]);
-
-	remove_proc_entry("sputrace", NULL);
-	kfree(sputrace_log);
-	marker_synchronize_unregister();
-}
-
-module_init(sputrace_init);
-module_exit(sputrace_exit);
-
-MODULE_LICENSE("GPL");
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/context.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/context.c	2009-05-14 18:52:09.608784652 +0200
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/context.c	2009-06-12 16:25:33.804963722 +0200
@@ -28,6 +28,7 @@
 #include <asm/spu.h>
 #include <asm/spu_csa.h>
 #include "spufs.h"
+#include "sputrace.h"
 
 
 atomic_t nr_spu_contexts = ATOMIC_INIT(0);
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/file.c	2009-05-14 18:52:09.616784830 +0200
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/file.c	2009-06-12 16:25:33.805963360 +0200
@@ -38,6 +38,7 @@
 #include <asm/uaccess.h>
 
 #include "spufs.h"
+#include "sputrace.h"
 
 #define SPUFS_MMAP_4K (PAGE_SIZE == 0x1000)
 
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/sched.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/sched.c	2009-05-14 18:52:09.659784570 +0200
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/sched.c	2009-06-12 16:25:33.807814224 +0200
@@ -47,6 +47,8 @@
 #include <asm/spu_csa.h>
 #include <asm/spu_priv1.h>
 #include "spufs.h"
+#define CREATE_TRACE_POINTS
+#include "sputrace.h"
 
 struct spu_prio_array {
 	DECLARE_BITMAP(bitmap, MAX_PRIO);



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