Commit 038200cf authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Paul Mackerras

[POWERPC] spufs: Add marker-based tracing facility

This adds markers two important points in the spufs code and a new
module (sputrace.ko) that allows reading these out through a proc file.

Long-term I'd rather see something like lttng extended to use the spufs
instrumentation, but for now I think this is a good enough quick
solution.  We'll probably want to add various addition event in addition
to that ones I have already.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 551e4fb2
......@@ -54,6 +54,13 @@ 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
......
......@@ -4,6 +4,8 @@ spufs-y += inode.o file.o context.o syscalls.o coredump.o
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
# Rules to build switch.o with the help of SPU tool chain
SPU_CROSS := spu-
SPU_CC := $(SPU_CROSS)gcc
......
......@@ -29,6 +29,7 @@
#include <linux/poll.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>
#include <linux/marker.h>
#include <asm/io.h>
#include <asm/semaphore.h>
......@@ -358,6 +359,8 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
struct spu_context *ctx = vma->vm_file->private_data;
unsigned long area, offset = address - vma->vm_start;
spu_context_nospu_trace(spufs_ps_nopfn__enter, ctx);
offset += vma->vm_pgoff << PAGE_SHIFT;
if (offset >= ps_size)
return NOPFN_SIGBUS;
......@@ -375,11 +378,14 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
if (ctx->state == SPU_STATE_SAVED) {
up_read(&current->mm->mmap_sem);
spu_context_nospu_trace(spufs_ps_nopfn__sleep, ctx);
spufs_wait(ctx->run_wq, ctx->state == SPU_STATE_RUNNABLE);
spu_context_trace(spufs_ps_nopfn__wake, ctx, ctx->spu);
down_read(&current->mm->mmap_sem);
} else {
area = ctx->spu->problem_phys + ps_offs;
vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
spu_context_trace(spufs_ps_nopfn__insert, ctx, ctx->spu);
}
spu_release(ctx);
......
......@@ -39,6 +39,7 @@
#include <linux/pid_namespace.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/marker.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
......@@ -216,8 +217,8 @@ void do_notify_spus_active(void)
*/
static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
{
pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
spu->number, spu->node);
spu_context_trace(spu_bind_context__enter, ctx, spu);
spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
if (ctx->flags & SPU_CREATE_NOSCHED)
......@@ -399,8 +400,8 @@ static int has_affinity(struct spu_context *ctx)
*/
static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
{
pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
spu->pid, spu->number, spu->node);
spu_context_trace(spu_unbind_context__enter, ctx, spu);
spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
if (spu->ctx->flags & SPU_CREATE_NOSCHED)
......@@ -528,6 +529,8 @@ static struct spu *spu_get_idle(struct spu_context *ctx)
struct spu *spu, *aff_ref_spu;
int node, n;
spu_context_nospu_trace(spu_get_idle__enter, ctx);
if (ctx->gang) {
mutex_lock(&ctx->gang->aff_mutex);
if (has_affinity(ctx)) {
......@@ -546,8 +549,7 @@ static struct spu *spu_get_idle(struct spu_context *ctx)
if (atomic_dec_and_test(&ctx->gang->aff_sched_count))
ctx->gang->aff_ref_spu = NULL;
mutex_unlock(&ctx->gang->aff_mutex);
return NULL;
goto not_found;
}
mutex_unlock(&ctx->gang->aff_mutex);
}
......@@ -565,12 +567,14 @@ static struct spu *spu_get_idle(struct spu_context *ctx)
mutex_unlock(&cbe_spu_info[node].list_mutex);
}
not_found:
spu_context_nospu_trace(spu_get_idle__not_found, ctx);
return NULL;
found:
spu->alloc_state = SPU_USED;
mutex_unlock(&cbe_spu_info[node].list_mutex);
pr_debug("Got SPU %d %d\n", spu->number, spu->node);
spu_context_trace(spu_get_idle__found, ctx, spu);
spu_init_channels(spu);
return spu;
}
......@@ -587,6 +591,8 @@ static struct spu *find_victim(struct spu_context *ctx)
struct spu *spu;
int node, n;
spu_context_nospu_trace(spu_find_vitim__enter, ctx);
/*
* Look for a possible preemption candidate on the local node first.
* If there is no candidate look at the other nodes. This isn't
......@@ -640,6 +646,8 @@ static struct spu *find_victim(struct spu_context *ctx)
goto restart;
}
spu_context_trace(__spu_deactivate__unload, ctx, spu);
mutex_lock(&cbe_spu_info[node].list_mutex);
cbe_spu_info[node].nr_active--;
spu_unbind_context(spu, victim);
......@@ -822,6 +830,7 @@ static int __spu_deactivate(struct spu_context *ctx, int force, int max_prio)
*/
void spu_deactivate(struct spu_context *ctx)
{
spu_context_nospu_trace(spu_deactivate__enter, ctx);
__spu_deactivate(ctx, 1, MAX_PRIO);
}
......@@ -835,6 +844,7 @@ void spu_deactivate(struct spu_context *ctx)
*/
void spu_yield(struct spu_context *ctx)
{
spu_context_nospu_trace(spu_yield__enter, ctx);
if (!(ctx->flags & SPU_CREATE_NOSCHED)) {
mutex_lock(&ctx->state_mutex);
__spu_deactivate(ctx, 0, MAX_PRIO);
......@@ -864,11 +874,15 @@ static noinline void spusched_tick(struct spu_context *ctx)
goto out;
spu = ctx->spu;
spu_context_trace(spusched_tick__preempt, ctx, spu);
new = grab_runnable_context(ctx->prio + 1, spu->node);
if (new) {
spu_unschedule(spu, ctx);
spu_add_to_rq(ctx);
} else {
spu_context_nospu_trace(spusched_tick__newslice, ctx);
ctx->time_slice++;
}
out:
......
......@@ -325,4 +325,9 @@ extern void spu_free_lscsa(struct spu_state *csa);
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, "%p %p", ctx, spu);
#define spu_context_nospu_trace(name, ctx) \
trace_mark(name, "%p", ctx);
#endif
/*
* 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_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 (thread = %d, spu = %d)\n",
(unsigned long) tv.tv_sec,
(unsigned long) tv.tv_nsec,
t->owner_tid,
t->name,
t->curr_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;
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)
{
spin_lock(&sputrace_lock);
sputrace_head = sputrace_tail = 0;
sputrace_start = ktime_get();
spin_unlock(&sputrace_lock);
return 0;
}
static const struct file_operations sputrace_fops = {
.owner = THIS_MODULE,
.open = sputrace_open,
.read = sputrace_read,
};
static void sputrace_log_item(const char *name, struct spu_context *ctx,
struct spu *spu)
{
spin_lock(&sputrace_lock);
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(const struct marker *mdata,
void *private, const char *format, ...)
{
struct spu_probe *p = mdata->private;
va_list ap;
struct spu_context *ctx;
struct spu *spu;
va_start(ap, format);
ctx = va_arg(ap, struct spu_context *);
spu = va_arg(ap, struct spu *);
sputrace_log_item(p->name, ctx, spu);
va_end(ap);
}
static void spu_context_nospu_event(const struct marker *mdata,
void *private, const char *format, ...)
{
struct spu_probe *p = mdata->private;
va_list ap;
struct spu_context *ctx;
va_start(ap, format);
ctx = va_arg(ap, struct spu_context *);
sputrace_log_item(p->name, ctx, NULL);
va_end(ap);
}
struct spu_probe spu_probes[] = {
{ "spu_bind_context__enter", "%p %p", spu_context_event },
{ "spu_unbind_context__enter", "%p %p", spu_context_event },
{ "spu_get_idle__enter", "%p", spu_context_nospu_event },
{ "spu_get_idle__found", "%p %p", spu_context_event },
{ "spu_get_idle__not_found", "%p", spu_context_nospu_event },
{ "spu_find_victim__enter", "%p", spu_context_nospu_event },
{ "spusched_tick__preempt", "%p %p", spu_context_event },
{ "spusched_tick__newslice", "%p", spu_context_nospu_event },
{ "spu_yield__enter", "%p", spu_context_nospu_event },
{ "spu_deactivate__enter", "%p", spu_context_nospu_event },
{ "__spu_deactivate__unload", "%p %p", spu_context_event },
{ "spufs_ps_nopfn__enter", "%p", spu_context_nospu_event },
{ "spufs_ps_nopfn__sleep", "%p", spu_context_nospu_event },
{ "spufs_ps_nopfn__wake", "%p %p", spu_context_event },
{ "spufs_ps_nopfn__insert", "%p %p", spu_context_event },
{ "spu_acquire_saved__enter", "%p", spu_context_nospu_event },
{ "destroy_spu_context__enter", "%p", spu_context_nospu_event },
};
static int __init sputrace_init(void)
{
struct proc_dir_entry *entry;
int i, error = -ENOMEM;
sputrace_log = kcalloc(sizeof(struct sputrace),
bufsize, GFP_KERNEL);
if (!sputrace_log)
goto out;
entry = create_proc_entry("sputrace", S_IRUSR, NULL);
if (!entry)
goto out_free_log;
entry->proc_fops = &sputrace_fops;
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);
error = marker_arm(p->name);
if (error)
printk(KERN_INFO "Unable to arm 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);
remove_proc_entry("sputrace", NULL);
kfree(sputrace_log);
}
module_init(sputrace_init);
module_exit(sputrace_exit);
MODULE_LICENSE("GPL");
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