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Message-ID: <20081225165838.GA31627@elte.hu>
Date: Thu, 25 Dec 2008 17:58:38 +0100
From: Ingo Molnar <mingo@...e.hu>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org,
Andrew Morton <akpm@...ux-foundation.org>,
Robert Richter <robert.richter@....com>,
Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>
Subject: [git pull] OProfile updates for v2.6.29
Linus,
Please pull the latest oprofile-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git oprofile-for-linus
[ it merges without conflicts with the x86 tree and with the tracing tree. ]
Thanks,
Ingo
------------------>
Ingo Molnar (1):
oprofile: select RING_BUFFER
Robert Richter (19):
oprofile: comment cleanup
oprofile: update comment for oprofile_add_sample()
oprofile: whitspace changes only
oprofile: fix typo
x86/oprofile: reordering IBS code in op_model_amd.c
x86/oprofile: cleanup IBS init/exit functions in op_model_amd.c
oprofile: implement switch/case in buffer_sync.c
oprofile: set values to default when creating oprofilefs
ring_buffer: update description for ring_buffer_alloc()
ftrace: remove unused function arg in trace_iterator_increment()
oprofile: adding cpu buffer r/w access functions
oprofile: adding cpu_buffer_write_commit()
oprofile: adding cpu_buffer_entries()
oprofile: moving cpu_buffer_reset() to cpu_buffer.h
ring_buffer: add remaining cpu functions to ring_buffer.h
oprofile: port to the new ring_buffer
oprofile: remove nr_available_slots()
oprofile: fix lost sample counter
ring_buffer: adding EXPORT_SYMBOLs
arch/Kconfig | 2 +
arch/x86/oprofile/op_model_amd.c | 89 +++++++++--------
drivers/oprofile/buffer_sync.c | 117 ++++++++--------------
drivers/oprofile/cpu_buffer.c | 197 +++++++++++++++++++------------------
drivers/oprofile/cpu_buffer.h | 69 +++++++++++++-
drivers/oprofile/oprofile_files.c | 15 +++-
include/linux/oprofile.h | 3 +-
include/linux/ring_buffer.h | 2 +
kernel/trace/ring_buffer.c | 36 +++++++-
kernel/trace/trace.c | 4 +-
10 files changed, 306 insertions(+), 228 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 471e72d..2e13aa2 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -6,6 +6,8 @@ config OPROFILE
tristate "OProfile system profiling (EXPERIMENTAL)"
depends on PROFILING
depends on HAVE_OPROFILE
+ select TRACING
+ select RING_BUFFER
help
OProfile is a profiling system capable of profiling the
whole system, include the kernel, kernel modules, libraries,
diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index 5095137..98658f2 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -65,11 +65,13 @@ static unsigned long reset_value[NUM_COUNTERS];
#define IBS_FETCH_BEGIN 3
#define IBS_OP_BEGIN 4
-/* The function interface needs to be fixed, something like add
- data. Should then be added to linux/oprofile.h. */
+/*
+ * The function interface needs to be fixed, something like add
+ * data. Should then be added to linux/oprofile.h.
+ */
extern void
-oprofile_add_ibs_sample(struct pt_regs *const regs,
- unsigned int *const ibs_sample, int ibs_code);
+oprofile_add_ibs_sample(struct pt_regs * const regs,
+ unsigned int * const ibs_sample, int ibs_code);
struct ibs_fetch_sample {
/* MSRC001_1031 IBS Fetch Linear Address Register */
@@ -104,11 +106,6 @@ struct ibs_op_sample {
unsigned int ibs_dc_phys_high;
};
-/*
- * unitialize the APIC for the IBS interrupts if needed on AMD Family10h+
-*/
-static void clear_ibs_nmi(void);
-
static int ibs_allowed; /* AMD Family10h and later */
struct op_ibs_config {
@@ -223,7 +220,7 @@ op_amd_handle_ibs(struct pt_regs * const regs,
(unsigned int *)&ibs_fetch,
IBS_FETCH_BEGIN);
- /*reenable the IRQ */
+ /* reenable the IRQ */
rdmsr(MSR_AMD64_IBSFETCHCTL, low, high);
high &= ~IBS_FETCH_HIGH_VALID_BIT;
high |= IBS_FETCH_HIGH_ENABLE;
@@ -331,8 +328,10 @@ static void op_amd_stop(struct op_msrs const * const msrs)
unsigned int low, high;
int i;
- /* Subtle: stop on all counters to avoid race with
- * setting our pm callback */
+ /*
+ * Subtle: stop on all counters to avoid race with setting our
+ * pm callback
+ */
for (i = 0 ; i < NUM_COUNTERS ; ++i) {
if (!reset_value[i])
continue;
@@ -343,13 +342,15 @@ static void op_amd_stop(struct op_msrs const * const msrs)
#ifdef CONFIG_OPROFILE_IBS
if (ibs_allowed && ibs_config.fetch_enabled) {
- low = 0; /* clear max count and enable */
+ /* clear max count and enable */
+ low = 0;
high = 0;
wrmsr(MSR_AMD64_IBSFETCHCTL, low, high);
}
if (ibs_allowed && ibs_config.op_enabled) {
- low = 0; /* clear max count and enable */
+ /* clear max count and enable */
+ low = 0;
high = 0;
wrmsr(MSR_AMD64_IBSOPCTL, low, high);
}
@@ -370,18 +371,7 @@ static void op_amd_shutdown(struct op_msrs const * const msrs)
}
}
-#ifndef CONFIG_OPROFILE_IBS
-
-/* no IBS support */
-
-static int op_amd_init(struct oprofile_operations *ops)
-{
- return 0;
-}
-
-static void op_amd_exit(void) {}
-
-#else
+#ifdef CONFIG_OPROFILE_IBS
static u8 ibs_eilvt_off;
@@ -395,7 +385,7 @@ static inline void apic_clear_ibs_nmi_per_cpu(void *arg)
setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_FIX, 1);
}
-static int pfm_amd64_setup_eilvt(void)
+static int init_ibs_nmi(void)
{
#define IBSCTL_LVTOFFSETVAL (1 << 8)
#define IBSCTL 0x1cc
@@ -443,18 +433,22 @@ static int pfm_amd64_setup_eilvt(void)
return 0;
}
-/*
- * initialize the APIC for the IBS interrupts
- * if available (AMD Family10h rev B0 and later)
- */
-static void setup_ibs(void)
+/* uninitialize the APIC for the IBS interrupts if needed */
+static void clear_ibs_nmi(void)
+{
+ if (ibs_allowed)
+ on_each_cpu(apic_clear_ibs_nmi_per_cpu, NULL, 1);
+}
+
+/* initialize the APIC for the IBS interrupts if available */
+static void ibs_init(void)
{
ibs_allowed = boot_cpu_has(X86_FEATURE_IBS);
if (!ibs_allowed)
return;
- if (pfm_amd64_setup_eilvt()) {
+ if (init_ibs_nmi()) {
ibs_allowed = 0;
return;
}
@@ -462,14 +456,12 @@ static void setup_ibs(void)
printk(KERN_INFO "oprofile: AMD IBS detected\n");
}
-
-/*
- * unitialize the APIC for the IBS interrupts if needed on AMD Family10h
- * rev B0 and later */
-static void clear_ibs_nmi(void)
+static void ibs_exit(void)
{
- if (ibs_allowed)
- on_each_cpu(apic_clear_ibs_nmi_per_cpu, NULL, 1);
+ if (!ibs_allowed)
+ return;
+
+ clear_ibs_nmi();
}
static int (*create_arch_files)(struct super_block *sb, struct dentry *root);
@@ -519,7 +511,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root)
static int op_amd_init(struct oprofile_operations *ops)
{
- setup_ibs();
+ ibs_init();
create_arch_files = ops->create_files;
ops->create_files = setup_ibs_files;
return 0;
@@ -527,10 +519,21 @@ static int op_amd_init(struct oprofile_operations *ops)
static void op_amd_exit(void)
{
- clear_ibs_nmi();
+ ibs_exit();
}
-#endif
+#else
+
+/* no IBS support */
+
+static int op_amd_init(struct oprofile_operations *ops)
+{
+ return 0;
+}
+
+static void op_amd_exit(void) {}
+
+#endif /* CONFIG_OPROFILE_IBS */
struct op_x86_model_spec const op_amd_spec = {
.init = op_amd_init,
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index b55cd23..737bd94 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -268,18 +268,6 @@ lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset)
return cookie;
}
-static void increment_tail(struct oprofile_cpu_buffer *b)
-{
- unsigned long new_tail = b->tail_pos + 1;
-
- rmb(); /* be sure fifo pointers are synchromized */
-
- if (new_tail < b->buffer_size)
- b->tail_pos = new_tail;
- else
- b->tail_pos = 0;
-}
-
static unsigned long last_cookie = INVALID_COOKIE;
static void add_cpu_switch(int i)
@@ -331,28 +319,25 @@ static void add_trace_begin(void)
#define IBS_FETCH_CODE_SIZE 2
#define IBS_OP_CODE_SIZE 5
-#define IBS_EIP(offset) \
- (((struct op_sample *)&cpu_buf->buffer[(offset)])->eip)
-#define IBS_EVENT(offset) \
- (((struct op_sample *)&cpu_buf->buffer[(offset)])->event)
/*
* Add IBS fetch and op entries to event buffer
*/
-static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
- struct mm_struct *mm)
+static void add_ibs_begin(int cpu, int code, struct mm_struct *mm)
{
unsigned long rip;
int i, count;
unsigned long ibs_cookie = 0;
off_t offset;
+ struct op_sample *sample;
- increment_tail(cpu_buf); /* move to RIP entry */
-
- rip = IBS_EIP(cpu_buf->tail_pos);
+ sample = cpu_buffer_read_entry(cpu);
+ if (!sample)
+ goto Error;
+ rip = sample->eip;
#ifdef __LP64__
- rip += IBS_EVENT(cpu_buf->tail_pos) << 32;
+ rip += sample->event << 32;
#endif
if (mm) {
@@ -376,8 +361,8 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
add_event_entry(offset); /* Offset from Dcookie */
/* we send the Dcookie offset, but send the raw Linear Add also*/
- add_event_entry(IBS_EIP(cpu_buf->tail_pos));
- add_event_entry(IBS_EVENT(cpu_buf->tail_pos));
+ add_event_entry(sample->eip);
+ add_event_entry(sample->event);
if (code == IBS_FETCH_CODE)
count = IBS_FETCH_CODE_SIZE; /*IBS FETCH is 2 int64s*/
@@ -385,10 +370,17 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
count = IBS_OP_CODE_SIZE; /*IBS OP is 5 int64s*/
for (i = 0; i < count; i++) {
- increment_tail(cpu_buf);
- add_event_entry(IBS_EIP(cpu_buf->tail_pos));
- add_event_entry(IBS_EVENT(cpu_buf->tail_pos));
+ sample = cpu_buffer_read_entry(cpu);
+ if (!sample)
+ goto Error;
+ add_event_entry(sample->eip);
+ add_event_entry(sample->event);
}
+
+ return;
+
+Error:
+ return;
}
#endif
@@ -466,33 +458,6 @@ static inline int is_code(unsigned long val)
}
-/* "acquire" as many cpu buffer slots as we can */
-static unsigned long get_slots(struct oprofile_cpu_buffer *b)
-{
- unsigned long head = b->head_pos;
- unsigned long tail = b->tail_pos;
-
- /*
- * Subtle. This resets the persistent last_task
- * and in_kernel values used for switching notes.
- * BUT, there is a small window between reading
- * head_pos, and this call, that means samples
- * can appear at the new head position, but not
- * be prefixed with the notes for switching
- * kernel mode or a task switch. This small hole
- * can lead to mis-attribution or samples where
- * we don't know if it's in the kernel or not,
- * at the start of an event buffer.
- */
- cpu_buffer_reset(b);
-
- if (head >= tail)
- return head - tail;
-
- return head + (b->buffer_size - tail);
-}
-
-
/* Move tasks along towards death. Any tasks on dead_tasks
* will definitely have no remaining references in any
* CPU buffers at this point, because we use two lists,
@@ -559,61 +524,61 @@ typedef enum {
*/
void sync_buffer(int cpu)
{
- struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
struct mm_struct *mm = NULL;
+ struct mm_struct *oldmm;
struct task_struct *new;
unsigned long cookie = 0;
int in_kernel = 1;
sync_buffer_state state = sb_buffer_start;
-#ifndef CONFIG_OPROFILE_IBS
unsigned int i;
unsigned long available;
-#endif
mutex_lock(&buffer_mutex);
add_cpu_switch(cpu);
- /* Remember, only we can modify tail_pos */
-
-#ifndef CONFIG_OPROFILE_IBS
- available = get_slots(cpu_buf);
+ cpu_buffer_reset(cpu);
+ available = cpu_buffer_entries(cpu);
for (i = 0; i < available; ++i) {
-#else
- while (get_slots(cpu_buf)) {
-#endif
- struct op_sample *s = &cpu_buf->buffer[cpu_buf->tail_pos];
+ struct op_sample *s = cpu_buffer_read_entry(cpu);
+ if (!s)
+ break;
if (is_code(s->eip)) {
- if (s->event <= CPU_IS_KERNEL) {
+ switch (s->event) {
+ case 0:
+ case CPU_IS_KERNEL:
/* kernel/userspace switch */
in_kernel = s->event;
if (state == sb_buffer_start)
state = sb_sample_start;
add_kernel_ctx_switch(s->event);
- } else if (s->event == CPU_TRACE_BEGIN) {
+ break;
+ case CPU_TRACE_BEGIN:
state = sb_bt_start;
add_trace_begin();
+ break;
#ifdef CONFIG_OPROFILE_IBS
- } else if (s->event == IBS_FETCH_BEGIN) {
+ case IBS_FETCH_BEGIN:
state = sb_bt_start;
- add_ibs_begin(cpu_buf, IBS_FETCH_CODE, mm);
- } else if (s->event == IBS_OP_BEGIN) {
+ add_ibs_begin(cpu, IBS_FETCH_CODE, mm);
+ break;
+ case IBS_OP_BEGIN:
state = sb_bt_start;
- add_ibs_begin(cpu_buf, IBS_OP_CODE, mm);
+ add_ibs_begin(cpu, IBS_OP_CODE, mm);
+ break;
#endif
- } else {
- struct mm_struct *oldmm = mm;
-
+ default:
/* userspace context switch */
+ oldmm = mm;
new = (struct task_struct *)s->event;
-
release_mm(oldmm);
mm = take_tasks_mm(new);
if (mm != oldmm)
cookie = get_exec_dcookie(mm);
add_user_ctx_switch(new, cookie);
+ break;
}
} else if (state >= sb_bt_start &&
!add_sample(mm, s, in_kernel)) {
@@ -622,8 +587,6 @@ void sync_buffer(int cpu)
atomic_inc(&oprofile_stats.bt_lost_no_mapping);
}
}
-
- increment_tail(cpu_buf);
}
release_mm(mm);
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 01d38e7..6109096 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -28,6 +28,25 @@
#include "buffer_sync.h"
#include "oprof.h"
+#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.
+ */
+struct ring_buffer *op_ring_buffer_read;
+struct ring_buffer *op_ring_buffer_write;
DEFINE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);
static void wq_sync_buffer(struct work_struct *work);
@@ -37,12 +56,12 @@ static int work_enabled;
void free_cpu_buffers(void)
{
- int i;
-
- for_each_possible_cpu(i) {
- vfree(per_cpu(cpu_buffer, i).buffer);
- per_cpu(cpu_buffer, i).buffer = NULL;
- }
+ 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;
}
unsigned long oprofile_get_cpu_buffer_size(void)
@@ -64,14 +83,16 @@ int alloc_cpu_buffers(void)
unsigned long buffer_size = fs_cpu_buffer_size;
+ op_ring_buffer_read = ring_buffer_alloc(buffer_size, OP_BUFFER_FLAGS);
+ if (!op_ring_buffer_read)
+ goto fail;
+ op_ring_buffer_write = ring_buffer_alloc(buffer_size, OP_BUFFER_FLAGS);
+ if (!op_ring_buffer_write)
+ goto fail;
+
for_each_possible_cpu(i) {
struct oprofile_cpu_buffer *b = &per_cpu(cpu_buffer, i);
- b->buffer = vmalloc_node(sizeof(struct op_sample) * buffer_size,
- cpu_to_node(i));
- if (!b->buffer)
- goto fail;
-
b->last_task = NULL;
b->last_is_kernel = -1;
b->tracing = 0;
@@ -124,57 +145,31 @@ void end_cpu_work(void)
flush_scheduled_work();
}
-/* Resets the cpu buffer to a sane state. */
-void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf)
-{
- /* reset these to invalid values; the next sample
- * collected will populate the buffer with proper
- * values to initialize the buffer
- */
- cpu_buf->last_is_kernel = -1;
- cpu_buf->last_task = NULL;
-}
-
-/* compute number of available slots in cpu_buffer queue */
-static unsigned long nr_available_slots(struct oprofile_cpu_buffer const *b)
+static inline int
+add_sample(struct oprofile_cpu_buffer *cpu_buf,
+ unsigned long pc, unsigned long event)
{
- unsigned long head = b->head_pos;
- unsigned long tail = b->tail_pos;
+ struct op_entry entry;
+ int ret;
- if (tail > head)
- return (tail - head) - 1;
+ ret = cpu_buffer_write_entry(&entry);
+ if (ret)
+ return ret;
- return tail + (b->buffer_size - head) - 1;
-}
+ entry.sample->eip = pc;
+ entry.sample->event = event;
-static void increment_head(struct oprofile_cpu_buffer *b)
-{
- unsigned long new_head = b->head_pos + 1;
-
- /* Ensure anything written to the slot before we
- * increment is visible */
- wmb();
-
- if (new_head < b->buffer_size)
- b->head_pos = new_head;
- else
- b->head_pos = 0;
-}
+ ret = cpu_buffer_write_commit(&entry);
+ if (ret)
+ return ret;
-static inline void
-add_sample(struct oprofile_cpu_buffer *cpu_buf,
- unsigned long pc, unsigned long event)
-{
- struct op_sample *entry = &cpu_buf->buffer[cpu_buf->head_pos];
- entry->eip = pc;
- entry->event = event;
- increment_head(cpu_buf);
+ return 0;
}
-static inline void
+static inline int
add_code(struct oprofile_cpu_buffer *buffer, unsigned long value)
{
- add_sample(buffer, ESCAPE_CODE, value);
+ return add_sample(buffer, ESCAPE_CODE, value);
}
/* This must be safe from any context. It's safe writing here
@@ -198,11 +193,6 @@ static int log_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc,
return 0;
}
- if (nr_available_slots(cpu_buf) < 3) {
- cpu_buf->sample_lost_overflow++;
- return 0;
- }
-
is_kernel = !!is_kernel;
task = current;
@@ -210,26 +200,29 @@ static int log_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc,
/* notice a switch from user->kernel or vice versa */
if (cpu_buf->last_is_kernel != is_kernel) {
cpu_buf->last_is_kernel = is_kernel;
- add_code(cpu_buf, is_kernel);
+ if (add_code(cpu_buf, is_kernel))
+ goto fail;
}
/* notice a task switch */
if (cpu_buf->last_task != task) {
cpu_buf->last_task = task;
- add_code(cpu_buf, (unsigned long)task);
+ if (add_code(cpu_buf, (unsigned long)task))
+ goto fail;
}
- add_sample(cpu_buf, pc, event);
+ if (add_sample(cpu_buf, pc, event))
+ goto fail;
+
return 1;
+
+fail:
+ cpu_buf->sample_lost_overflow++;
+ return 0;
}
static int oprofile_begin_trace(struct oprofile_cpu_buffer *cpu_buf)
{
- if (nr_available_slots(cpu_buf) < 4) {
- cpu_buf->sample_lost_overflow++;
- return 0;
- }
-
add_code(cpu_buf, CPU_TRACE_BEGIN);
cpu_buf->tracing = 1;
return 1;
@@ -253,8 +246,10 @@ void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
if (!oprofile_begin_trace(cpu_buf))
return;
- /* if log_sample() fail we can't backtrace since we lost the source
- * of this event */
+ /*
+ * if log_sample() fail we can't backtrace since we lost the
+ * source of this event
+ */
if (log_sample(cpu_buf, pc, is_kernel, event))
oprofile_ops.backtrace(regs, backtrace_depth);
oprofile_end_trace(cpu_buf);
@@ -272,49 +267,55 @@ void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
#define MAX_IBS_SAMPLE_SIZE 14
-void oprofile_add_ibs_sample(struct pt_regs *const regs,
- unsigned int *const ibs_sample, int ibs_code)
+void oprofile_add_ibs_sample(struct pt_regs * const regs,
+ unsigned int * const ibs_sample, int ibs_code)
{
int is_kernel = !user_mode(regs);
struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(cpu_buffer);
struct task_struct *task;
+ int fail = 0;
cpu_buf->sample_received++;
- if (nr_available_slots(cpu_buf) < MAX_IBS_SAMPLE_SIZE) {
- /* we can't backtrace since we lost the source of this event */
- cpu_buf->sample_lost_overflow++;
- return;
- }
-
/* notice a switch from user->kernel or vice versa */
if (cpu_buf->last_is_kernel != is_kernel) {
+ if (add_code(cpu_buf, is_kernel))
+ goto fail;
cpu_buf->last_is_kernel = is_kernel;
- add_code(cpu_buf, is_kernel);
}
/* notice a task switch */
if (!is_kernel) {
task = current;
if (cpu_buf->last_task != task) {
+ if (add_code(cpu_buf, (unsigned long)task))
+ goto fail;
cpu_buf->last_task = task;
- add_code(cpu_buf, (unsigned long)task);
}
}
- add_code(cpu_buf, ibs_code);
- add_sample(cpu_buf, ibs_sample[0], ibs_sample[1]);
- add_sample(cpu_buf, ibs_sample[2], ibs_sample[3]);
- add_sample(cpu_buf, ibs_sample[4], ibs_sample[5]);
+ fail = fail || add_code(cpu_buf, ibs_code);
+ fail = fail || add_sample(cpu_buf, ibs_sample[0], ibs_sample[1]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[2], ibs_sample[3]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[4], ibs_sample[5]);
if (ibs_code == IBS_OP_BEGIN) {
- add_sample(cpu_buf, ibs_sample[6], ibs_sample[7]);
- add_sample(cpu_buf, ibs_sample[8], ibs_sample[9]);
- add_sample(cpu_buf, ibs_sample[10], ibs_sample[11]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[6], ibs_sample[7]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[8], ibs_sample[9]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[10], ibs_sample[11]);
}
+ if (fail)
+ goto fail;
+
if (backtrace_depth)
oprofile_ops.backtrace(regs, backtrace_depth);
+
+ return;
+
+fail:
+ cpu_buf->sample_lost_overflow++;
+ return;
}
#endif
@@ -332,21 +333,21 @@ void oprofile_add_trace(unsigned long pc)
if (!cpu_buf->tracing)
return;
- if (nr_available_slots(cpu_buf) < 1) {
- cpu_buf->tracing = 0;
- cpu_buf->sample_lost_overflow++;
- return;
- }
+ /*
+ * broken frame can give an eip with the same value as an
+ * escape code, abort the trace if we get it
+ */
+ if (pc == ESCAPE_CODE)
+ goto fail;
- /* broken frame can give an eip with the same value as an escape code,
- * abort the trace if we get it */
- if (pc == ESCAPE_CODE) {
- cpu_buf->tracing = 0;
- cpu_buf->backtrace_aborted++;
- return;
- }
+ if (add_sample(cpu_buf, pc, 0))
+ goto fail;
- add_sample(cpu_buf, pc, 0);
+ return;
+fail:
+ cpu_buf->tracing = 0;
+ cpu_buf->backtrace_aborted++;
+ return;
}
/*
diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h
index d3cc262..aacb0f0 100644
--- a/drivers/oprofile/cpu_buffer.h
+++ b/drivers/oprofile/cpu_buffer.h
@@ -15,6 +15,7 @@
#include <linux/workqueue.h>
#include <linux/cache.h>
#include <linux/sched.h>
+#include <linux/ring_buffer.h>
struct task_struct;
@@ -32,6 +33,12 @@ struct op_sample {
unsigned long event;
};
+struct op_entry {
+ struct ring_buffer_event *event;
+ struct op_sample *sample;
+ unsigned long irq_flags;
+};
+
struct oprofile_cpu_buffer {
volatile unsigned long head_pos;
volatile unsigned long tail_pos;
@@ -39,7 +46,6 @@ struct oprofile_cpu_buffer {
struct task_struct *last_task;
int last_is_kernel;
int tracing;
- struct op_sample *buffer;
unsigned long sample_received;
unsigned long sample_lost_overflow;
unsigned long backtrace_aborted;
@@ -48,9 +54,68 @@ struct oprofile_cpu_buffer {
struct delayed_work work;
};
+extern struct ring_buffer *op_ring_buffer_read;
+extern struct ring_buffer *op_ring_buffer_write;
DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);
-void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf);
+/*
+ * Resets the cpu buffer to a sane state.
+ *
+ * reset these to invalid values; the next sample collected will
+ * populate the buffer with proper values to initialize the buffer
+ */
+static inline void cpu_buffer_reset(int cpu)
+{
+ struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
+
+ cpu_buf->last_is_kernel = -1;
+ cpu_buf->last_task = NULL;
+}
+
+static inline int cpu_buffer_write_entry(struct op_entry *entry)
+{
+ entry->event = ring_buffer_lock_reserve(op_ring_buffer_write,
+ sizeof(struct op_sample),
+ &entry->irq_flags);
+ if (entry->event)
+ entry->sample = ring_buffer_event_data(entry->event);
+ else
+ entry->sample = NULL;
+
+ if (!entry->sample)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static inline int cpu_buffer_write_commit(struct op_entry *entry)
+{
+ return ring_buffer_unlock_commit(op_ring_buffer_write, entry->event,
+ entry->irq_flags);
+}
+
+static inline struct op_sample *cpu_buffer_read_entry(int cpu)
+{
+ struct ring_buffer_event *e;
+ e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL);
+ if (e)
+ return ring_buffer_event_data(e);
+ if (ring_buffer_swap_cpu(op_ring_buffer_read,
+ op_ring_buffer_write,
+ cpu))
+ return NULL;
+ e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL);
+ if (e)
+ return ring_buffer_event_data(e);
+ return NULL;
+}
+
+/* "acquire" as many cpu buffer slots as we can */
+static inline unsigned long cpu_buffer_entries(int cpu)
+{
+ return ring_buffer_entries_cpu(op_ring_buffer_read, cpu)
+ + ring_buffer_entries_cpu(op_ring_buffer_write, cpu);
+}
/* transient events for the CPU buffer -> event buffer */
#define CPU_IS_KERNEL 1
diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c
index cc106d5..d820199 100644
--- a/drivers/oprofile/oprofile_files.c
+++ b/drivers/oprofile/oprofile_files.c
@@ -14,9 +14,13 @@
#include "oprofile_stats.h"
#include "oprof.h"
-unsigned long fs_buffer_size = 131072;
-unsigned long fs_cpu_buffer_size = 8192;
-unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
+#define FS_BUFFER_SIZE_DEFAULT 131072
+#define FS_CPU_BUFFER_SIZE_DEFAULT 8192
+#define FS_BUFFER_WATERSHED_DEFAULT 32768 /* FIXME: tune */
+
+unsigned long fs_buffer_size;
+unsigned long fs_cpu_buffer_size;
+unsigned long fs_buffer_watershed;
static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
@@ -120,6 +124,11 @@ static const struct file_operations dump_fops = {
void oprofile_create_files(struct super_block *sb, struct dentry *root)
{
+ /* reinitialize default values */
+ fs_buffer_size = FS_BUFFER_SIZE_DEFAULT;
+ fs_cpu_buffer_size = FS_CPU_BUFFER_SIZE_DEFAULT;
+ fs_buffer_watershed = FS_BUFFER_WATERSHED_DEFAULT;
+
oprofilefs_create_file(sb, root, "enable", &enable_fops);
oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h
index 5231861..1ce9fe5 100644
--- a/include/linux/oprofile.h
+++ b/include/linux/oprofile.h
@@ -86,8 +86,7 @@ int oprofile_arch_init(struct oprofile_operations * ops);
void oprofile_arch_exit(void);
/**
- * Add a sample. This may be called from any context. Pass
- * smp_processor_id() as cpu.
+ * Add a sample. This may be called from any context.
*/
void oprofile_add_sample(struct pt_regs * const regs, unsigned long event);
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index e097c2e..de9d8c1 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -116,6 +116,8 @@ void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);
unsigned long ring_buffer_entries(struct ring_buffer *buffer);
unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
+unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu);
+unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu);
u64 ring_buffer_time_stamp(int cpu);
void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 668bbb5..30d57dd 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -31,6 +31,7 @@ void tracing_on(void)
{
ring_buffers_off = 0;
}
+EXPORT_SYMBOL_GPL(tracing_on);
/**
* tracing_off - turn off all tracing buffers
@@ -44,6 +45,7 @@ void tracing_off(void)
{
ring_buffers_off = 1;
}
+EXPORT_SYMBOL_GPL(tracing_off);
/* Up this if you want to test the TIME_EXTENTS and normalization */
#define DEBUG_SHIFT 0
@@ -60,12 +62,14 @@ u64 ring_buffer_time_stamp(int cpu)
return time;
}
+EXPORT_SYMBOL_GPL(ring_buffer_time_stamp);
void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
{
/* Just stupid testing the normalize function and deltas */
*ts >>= DEBUG_SHIFT;
}
+EXPORT_SYMBOL_GPL(ring_buffer_normalize_time_stamp);
#define RB_EVNT_HDR_SIZE (sizeof(struct ring_buffer_event))
#define RB_ALIGNMENT_SHIFT 2
@@ -115,6 +119,7 @@ unsigned ring_buffer_event_length(struct ring_buffer_event *event)
{
return rb_event_length(event);
}
+EXPORT_SYMBOL_GPL(ring_buffer_event_length);
/* inline for ring buffer fast paths */
static inline void *
@@ -136,6 +141,7 @@ void *ring_buffer_event_data(struct ring_buffer_event *event)
{
return rb_event_data(event);
}
+EXPORT_SYMBOL_GPL(ring_buffer_event_data);
#define for_each_buffer_cpu(buffer, cpu) \
for_each_cpu_mask(cpu, buffer->cpumask)
@@ -381,7 +387,7 @@ extern int ring_buffer_page_too_big(void);
/**
* ring_buffer_alloc - allocate a new ring_buffer
- * @size: the size in bytes that is needed.
+ * @size: the size in bytes per cpu that is needed.
* @flags: attributes to set for the ring buffer.
*
* Currently the only flag that is available is the RB_FL_OVERWRITE
@@ -444,6 +450,7 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
kfree(buffer);
return NULL;
}
+EXPORT_SYMBOL_GPL(ring_buffer_alloc);
/**
* ring_buffer_free - free a ring buffer.
@@ -459,6 +466,7 @@ ring_buffer_free(struct ring_buffer *buffer)
kfree(buffer);
}
+EXPORT_SYMBOL_GPL(ring_buffer_free);
static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer);
@@ -620,6 +628,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
mutex_unlock(&buffer->mutex);
return -ENOMEM;
}
+EXPORT_SYMBOL_GPL(ring_buffer_resize);
static inline int rb_null_event(struct ring_buffer_event *event)
{
@@ -1220,6 +1229,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
preempt_enable_notrace();
return NULL;
}
+EXPORT_SYMBOL_GPL(ring_buffer_lock_reserve);
static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event)
@@ -1269,6 +1279,7 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
return 0;
}
+EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
/**
* ring_buffer_write - write data to the buffer without reserving
@@ -1334,6 +1345,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
return ret;
}
+EXPORT_SYMBOL_GPL(ring_buffer_write);
static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
{
@@ -1360,6 +1372,7 @@ void ring_buffer_record_disable(struct ring_buffer *buffer)
{
atomic_inc(&buffer->record_disabled);
}
+EXPORT_SYMBOL_GPL(ring_buffer_record_disable);
/**
* ring_buffer_record_enable - enable writes to the buffer
@@ -1372,6 +1385,7 @@ void ring_buffer_record_enable(struct ring_buffer *buffer)
{
atomic_dec(&buffer->record_disabled);
}
+EXPORT_SYMBOL_GPL(ring_buffer_record_enable);
/**
* ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer
@@ -1393,6 +1407,7 @@ void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
cpu_buffer = buffer->buffers[cpu];
atomic_inc(&cpu_buffer->record_disabled);
}
+EXPORT_SYMBOL_GPL(ring_buffer_record_disable_cpu);
/**
* ring_buffer_record_enable_cpu - enable writes to the buffer
@@ -1412,6 +1427,7 @@ void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
cpu_buffer = buffer->buffers[cpu];
atomic_dec(&cpu_buffer->record_disabled);
}
+EXPORT_SYMBOL_GPL(ring_buffer_record_enable_cpu);
/**
* ring_buffer_entries_cpu - get the number of entries in a cpu buffer
@@ -1428,6 +1444,7 @@ unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
cpu_buffer = buffer->buffers[cpu];
return cpu_buffer->entries;
}
+EXPORT_SYMBOL_GPL(ring_buffer_entries_cpu);
/**
* ring_buffer_overrun_cpu - get the number of overruns in a cpu_buffer
@@ -1444,6 +1461,7 @@ unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
cpu_buffer = buffer->buffers[cpu];
return cpu_buffer->overrun;
}
+EXPORT_SYMBOL_GPL(ring_buffer_overrun_cpu);
/**
* ring_buffer_entries - get the number of entries in a buffer
@@ -1466,6 +1484,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer)
return entries;
}
+EXPORT_SYMBOL_GPL(ring_buffer_entries);
/**
* ring_buffer_overrun_cpu - get the number of overruns in buffer
@@ -1488,6 +1507,7 @@ unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
return overruns;
}
+EXPORT_SYMBOL_GPL(ring_buffer_overruns);
/**
* ring_buffer_iter_reset - reset an iterator
@@ -1513,6 +1533,7 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter)
else
iter->read_stamp = iter->head_page->time_stamp;
}
+EXPORT_SYMBOL_GPL(ring_buffer_iter_reset);
/**
* ring_buffer_iter_empty - check if an iterator has no more to read
@@ -1527,6 +1548,7 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
return iter->head_page == cpu_buffer->commit_page &&
iter->head == rb_commit_index(cpu_buffer);
}
+EXPORT_SYMBOL_GPL(ring_buffer_iter_empty);
static void
rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer,
@@ -1797,6 +1819,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
return NULL;
}
+EXPORT_SYMBOL_GPL(ring_buffer_peek);
/**
* ring_buffer_iter_peek - peek at the next event to be read
@@ -1867,6 +1890,7 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
return NULL;
}
+EXPORT_SYMBOL_GPL(ring_buffer_iter_peek);
/**
* ring_buffer_consume - return an event and consume it
@@ -1894,6 +1918,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts)
return event;
}
+EXPORT_SYMBOL_GPL(ring_buffer_consume);
/**
* ring_buffer_read_start - start a non consuming read of the buffer
@@ -1934,6 +1959,7 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
return iter;
}
+EXPORT_SYMBOL_GPL(ring_buffer_read_start);
/**
* ring_buffer_finish - finish reading the iterator of the buffer
@@ -1950,6 +1976,7 @@ ring_buffer_read_finish(struct ring_buffer_iter *iter)
atomic_dec(&cpu_buffer->record_disabled);
kfree(iter);
}
+EXPORT_SYMBOL_GPL(ring_buffer_read_finish);
/**
* ring_buffer_read - read the next item in the ring buffer by the iterator
@@ -1971,6 +1998,7 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
return event;
}
+EXPORT_SYMBOL_GPL(ring_buffer_read);
/**
* ring_buffer_size - return the size of the ring buffer (in bytes)
@@ -1980,6 +2008,7 @@ unsigned long ring_buffer_size(struct ring_buffer *buffer)
{
return BUF_PAGE_SIZE * buffer->pages;
}
+EXPORT_SYMBOL_GPL(ring_buffer_size);
static void
rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
@@ -2022,6 +2051,7 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
spin_unlock_irqrestore(&cpu_buffer->lock, flags);
}
+EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
/**
* ring_buffer_reset - reset a ring buffer
@@ -2034,6 +2064,7 @@ void ring_buffer_reset(struct ring_buffer *buffer)
for_each_buffer_cpu(buffer, cpu)
ring_buffer_reset_cpu(buffer, cpu);
}
+EXPORT_SYMBOL_GPL(ring_buffer_reset);
/**
* rind_buffer_empty - is the ring buffer empty?
@@ -2052,6 +2083,7 @@ int ring_buffer_empty(struct ring_buffer *buffer)
}
return 1;
}
+EXPORT_SYMBOL_GPL(ring_buffer_empty);
/**
* ring_buffer_empty_cpu - is a cpu buffer of a ring buffer empty?
@@ -2068,6 +2100,7 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
cpu_buffer = buffer->buffers[cpu];
return rb_per_cpu_empty(cpu_buffer);
}
+EXPORT_SYMBOL_GPL(ring_buffer_empty_cpu);
/**
* ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers
@@ -2117,6 +2150,7 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
return 0;
}
+EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
static ssize_t
rb_simple_read(struct file *filp, char __user *ubuf,
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d86e325..a96b335 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -914,7 +914,7 @@ enum trace_file_type {
TRACE_FILE_LAT_FMT = 1,
};
-static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
+static void trace_iterator_increment(struct trace_iterator *iter)
{
/* Don't allow ftrace to trace into the ring buffers */
ftrace_disable_cpu();
@@ -993,7 +993,7 @@ static void *find_next_entry_inc(struct trace_iterator *iter)
iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
if (iter->ent)
- trace_iterator_increment(iter, iter->cpu);
+ trace_iterator_increment(iter);
return iter->ent ? iter : NULL;
}
--
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