* @author Barry Kasindorf <barry.kasindorf@amd.com>
* @author Robert Richter <robert.richter@amd.com>
*
- * Modified by Aravind Menon for Xen
- * These modifications are:
- * Copyright (C) 2005 Hewlett-Packard Co.
- *
* Each CPU has a local buffer that stores PC value/event
* pairs. We also log context switches when we notice them.
* Eventually each CPU's buffer is processed into the global
#define OP_BUFFER_FLAGS 0
-/*
- * Read and write access is using spin locking. Thus, writing to the
- * buffer by NMI handler (x86) could occur also during critical
- * sections when reading the buffer. To avoid this, there are 2
- * buffers for independent read and write access. Read access is in
- * process context only, write access only in the NMI handler. If the
- * read buffer runs empty, both buffers are swapped atomically. There
- * is potentially a small window during swapping where the buffers are
- * disabled and samples could be lost.
- *
- * Using 2 buffers is a little bit overhead, but the solution is clear
- * and does not require changes in the ring buffer implementation. It
- * can be changed to a single buffer solution when the ring buffer
- * access is implemented as non-locking atomic code.
- */
-static struct ring_buffer *op_ring_buffer_read;
-static struct ring_buffer *op_ring_buffer_write;
+static struct ring_buffer *op_ring_buffer;
DEFINE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);
static void wq_sync_buffer(struct work_struct *work);
#define DEFAULT_TIMER_EXPIRE (HZ / 10)
static int work_enabled;
-#ifndef CONFIG_XEN
-#define current_domain COORDINATOR_DOMAIN
-#else
-static int32_t current_domain = COORDINATOR_DOMAIN;
-#endif
-
unsigned long oprofile_get_cpu_buffer_size(void)
{
return oprofile_cpu_buffer_size;
void free_cpu_buffers(void)
{
- if (op_ring_buffer_read)
- ring_buffer_free(op_ring_buffer_read);
- op_ring_buffer_read = NULL;
- if (op_ring_buffer_write)
- ring_buffer_free(op_ring_buffer_write);
- op_ring_buffer_write = NULL;
+ if (op_ring_buffer)
+ ring_buffer_free(op_ring_buffer);
+ op_ring_buffer = NULL;
}
#define RB_EVENT_HDR_SIZE 4
unsigned long byte_size = buffer_size * (sizeof(struct op_sample) +
RB_EVENT_HDR_SIZE);
- op_ring_buffer_read = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
- if (!op_ring_buffer_read)
- goto fail;
- op_ring_buffer_write = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
- if (!op_ring_buffer_write)
+ op_ring_buffer = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
+ if (!op_ring_buffer)
goto fail;
for_each_possible_cpu(i) {
struct oprofile_cpu_buffer *b = &per_cpu(op_cpu_buffer, i);
b->last_task = NULL;
- b->last_cpu_mode = -1;
+ b->last_is_kernel = -1;
b->tracing = 0;
b->buffer_size = buffer_size;
b->sample_received = 0;
*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size)
{
entry->event = ring_buffer_lock_reserve
- (op_ring_buffer_write, sizeof(struct op_sample) +
+ (op_ring_buffer, sizeof(struct op_sample) +
size * sizeof(entry->sample->data[0]));
- if (entry->event)
- entry->sample = ring_buffer_event_data(entry->event);
- else
- entry->sample = NULL;
-
- if (!entry->sample)
+ if (!entry->event)
return NULL;
-
+ entry->sample = ring_buffer_event_data(entry->event);
entry->size = size;
entry->data = entry->sample->data;
int op_cpu_buffer_write_commit(struct op_entry *entry)
{
- return ring_buffer_unlock_commit(op_ring_buffer_write, entry->event);
+ return ring_buffer_unlock_commit(op_ring_buffer, entry->event);
}
struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu)
{
struct ring_buffer_event *e;
- e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL);
- if (e)
- goto event;
- if (ring_buffer_swap_cpu(op_ring_buffer_read,
- op_ring_buffer_write,
- cpu))
+ e = ring_buffer_consume(op_ring_buffer, cpu, NULL, NULL);
+ if (!e)
return NULL;
- e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL);
- if (e)
- goto event;
- return NULL;
-event:
entry->event = e;
entry->sample = ring_buffer_event_data(e);
entry->size = (ring_buffer_event_length(e) - sizeof(struct op_sample))
unsigned long op_cpu_buffer_entries(int cpu)
{
- return ring_buffer_entries_cpu(op_ring_buffer_read, cpu)
- + ring_buffer_entries_cpu(op_ring_buffer_write, cpu);
+ return ring_buffer_entries_cpu(op_ring_buffer, cpu);
}
static int
op_add_code(struct oprofile_cpu_buffer *cpu_buf, unsigned long backtrace,
- int cpu_mode, struct task_struct *task)
+ int is_kernel, struct task_struct *task)
{
struct op_entry entry;
struct op_sample *sample;
flags |= TRACE_BEGIN;
/* notice a switch from user->kernel or vice versa */
- if (cpu_buf->last_cpu_mode != cpu_mode) {
- cpu_buf->last_cpu_mode = cpu_mode;
- flags |= KERNEL_CTX_SWITCH | cpu_mode;
+ is_kernel = !!is_kernel;
+ if (cpu_buf->last_is_kernel != is_kernel) {
+ cpu_buf->last_is_kernel = is_kernel;
+ flags |= KERNEL_CTX_SWITCH;
+ if (is_kernel)
+ flags |= IS_KERNEL;
}
/* notice a task switch */
- /* if not processing other domain samples */
- if (cpu_buf->last_task != task &&
- current_domain == COORDINATOR_DOMAIN) {
+ if (cpu_buf->last_task != task) {
cpu_buf->last_task = task;
flags |= USER_CTX_SWITCH;
}
/*
* This must be safe from any context.
*
- * cpu_mode is needed because on some architectures you cannot
+ * is_kernel is needed because on some architectures you cannot
* tell if you are in kernel or user space simply by looking at
- * pc. We tag this in the buffer by generating kernel/user (and
- * xen) enter events whenever cpu_mode changes
+ * 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 cpu_mode, unsigned long event)
+ unsigned long backtrace, int is_kernel, unsigned long event)
{
cpu_buf->sample_received++;
return 0;
}
- if (op_add_code(cpu_buf, backtrace, cpu_mode, current))
+ if (op_add_code(cpu_buf, backtrace, is_kernel, current))
goto fail;
if (op_add_sample(cpu_buf, pc, event))
void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
{
- int is_kernel = !user_mode(regs);
- unsigned long pc = profile_pc(regs);
+ int is_kernel;
+ unsigned long pc;
+
+ if (likely(regs)) {
+ is_kernel = !user_mode(regs);
+ pc = profile_pc(regs);
+ } else {
+ is_kernel = 0; /* This value will not be used */
+ pc = ESCAPE_CODE; /* as this causes an early return. */
+ }
__oprofile_add_ext_sample(pc, regs, event, is_kernel);
}
log_sample(cpu_buf, pc, 0, is_kernel, event);
}
-#ifdef CONFIG_XEN
-/*
- * This is basically log_sample(b, ESCAPE_CODE, 1, cpu_mode, CPU_TRACE_BEGIN),
- * as was previously accessible through oprofile_add_pc().
- */
-void oprofile_add_mode(int cpu_mode)
-{
- struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
-
- if (op_add_code(cpu_buf, 1, cpu_mode, current))
- cpu_buf->sample_lost_overflow++;
-}
-#endif
-
void oprofile_add_trace(unsigned long pc)
{
struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
return;
}
-#ifdef CONFIG_XEN
-int oprofile_add_domain_switch(int32_t domain_id)
-{
- struct op_entry entry;
- struct op_sample *sample;
-
- sample = op_cpu_buffer_write_reserve(&entry, 1);
- if (!sample)
- return 0;
-
- sample->eip = ESCAPE_CODE;
- sample->event = DOMAIN_SWITCH;
-
- op_cpu_buffer_add_data(&entry, domain_id);
- op_cpu_buffer_write_commit(&entry);
-
- current_domain = domain_id;
-
- return 1;
-}
-#endif
-
/*
* This serves to avoid cpu buffer overflow, and makes sure
* the task mortuary progresses
projects / linux-flexiantxendom0-3.2.10.git / blobdiff