Merge branch 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  oprofile/x86: fix msr access to reserved counters
  oprofile/x86: use kzalloc() instead of kmalloc()
  oprofile/x86: fix perfctr nmi reservation for mulitplexing
  oprofile/x86: add comment to counter-in-use warning
  oprofile/x86: warn user if a counter is already active
  oprofile/x86: implement randomization for IBS periodic op counter
  oprofile/x86: implement lsfr pseudo-random number generator for IBS
  oprofile/x86: implement IBS cpuid feature detection
  oprofile/x86: remove node check in AMD IBS initialization
  oprofile/x86: remove OPROFILE_IBS config option
  oprofile: remove EXPERIMENTAL from the config option description
  oprofile: remove tracing build dependency
This commit is contained in:
Linus Torvalds 2010-02-28 10:15:31 -08:00
commit d25e8dbdab
7 changed files with 203 additions and 127 deletions

View File

@ -3,11 +3,9 @@
#
config OPROFILE
tristate "OProfile system profiling (EXPERIMENTAL)"
tristate "OProfile system profiling"
depends on PROFILING
depends on HAVE_OPROFILE
depends on TRACING_SUPPORT
select TRACING
select RING_BUFFER
select RING_BUFFER_ALLOW_SWAP
help
@ -17,20 +15,6 @@ config OPROFILE
If unsure, say N.
config OPROFILE_IBS
bool "OProfile AMD IBS support (EXPERIMENTAL)"
default n
depends on OPROFILE && SMP && X86
help
Instruction-Based Sampling (IBS) is a new profiling
technique that provides rich, precise program performance
information. IBS is introduced by AMD Family10h processors
(AMD Opteron Quad-Core processor "Barcelona") to overcome
the limitations of conventional performance counter
sampling.
If unsure, say N.
config OPROFILE_EVENT_MULTIPLEX
bool "OProfile multiplexing support (EXPERIMENTAL)"
default n

View File

@ -159,7 +159,7 @@ static int nmi_setup_mux(void)
for_each_possible_cpu(i) {
per_cpu(cpu_msrs, i).multiplex =
kmalloc(multiplex_size, GFP_KERNEL);
kzalloc(multiplex_size, GFP_KERNEL);
if (!per_cpu(cpu_msrs, i).multiplex)
return 0;
}
@ -179,7 +179,6 @@ static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
if (counter_config[i].enabled) {
multiplex[i].saved = -(u64)counter_config[i].count;
} else {
multiplex[i].addr = 0;
multiplex[i].saved = 0;
}
}
@ -189,25 +188,27 @@ static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
{
struct op_msr *counters = msrs->counters;
struct op_msr *multiplex = msrs->multiplex;
int i;
for (i = 0; i < model->num_counters; ++i) {
int virt = op_x86_phys_to_virt(i);
if (multiplex[virt].addr)
rdmsrl(multiplex[virt].addr, multiplex[virt].saved);
if (counters[i].addr)
rdmsrl(counters[i].addr, multiplex[virt].saved);
}
}
static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
{
struct op_msr *counters = msrs->counters;
struct op_msr *multiplex = msrs->multiplex;
int i;
for (i = 0; i < model->num_counters; ++i) {
int virt = op_x86_phys_to_virt(i);
if (multiplex[virt].addr)
wrmsrl(multiplex[virt].addr, multiplex[virt].saved);
if (counters[i].addr)
wrmsrl(counters[i].addr, multiplex[virt].saved);
}
}
@ -303,11 +304,11 @@ static int allocate_msrs(void)
int i;
for_each_possible_cpu(i) {
per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
per_cpu(cpu_msrs, i).counters = kzalloc(counters_size,
GFP_KERNEL);
if (!per_cpu(cpu_msrs, i).counters)
return 0;
per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
per_cpu(cpu_msrs, i).controls = kzalloc(controls_size,
GFP_KERNEL);
if (!per_cpu(cpu_msrs, i).controls)
return 0;

View File

@ -22,6 +22,9 @@
#include <asm/ptrace.h>
#include <asm/msr.h>
#include <asm/nmi.h>
#include <asm/apic.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include "op_x86_model.h"
#include "op_counter.h"
@ -43,15 +46,13 @@
static unsigned long reset_value[NUM_VIRT_COUNTERS];
#ifdef CONFIG_OPROFILE_IBS
/* IbsFetchCtl bits/masks */
#define IBS_FETCH_RAND_EN (1ULL<<57)
#define IBS_FETCH_VAL (1ULL<<49)
#define IBS_FETCH_ENABLE (1ULL<<48)
#define IBS_FETCH_CNT_MASK 0xFFFF0000ULL
/*IbsOpCtl bits */
/* IbsOpCtl bits */
#define IBS_OP_CNT_CTL (1ULL<<19)
#define IBS_OP_VAL (1ULL<<18)
#define IBS_OP_ENABLE (1ULL<<17)
@ -59,7 +60,7 @@ static unsigned long reset_value[NUM_VIRT_COUNTERS];
#define IBS_FETCH_SIZE 6
#define IBS_OP_SIZE 12
static int has_ibs; /* AMD Family10h and later */
static u32 ibs_caps;
struct op_ibs_config {
unsigned long op_enabled;
@ -71,24 +72,52 @@ struct op_ibs_config {
};
static struct op_ibs_config ibs_config;
static u64 ibs_op_ctl;
#endif
/*
* IBS cpuid feature detection
*/
#define IBS_CPUID_FEATURES 0x8000001b
/*
* Same bit mask as for IBS cpuid feature flags (Fn8000_001B_EAX), but
* bit 0 is used to indicate the existence of IBS.
*/
#define IBS_CAPS_AVAIL (1LL<<0)
#define IBS_CAPS_RDWROPCNT (1LL<<3)
#define IBS_CAPS_OPCNT (1LL<<4)
/*
* IBS randomization macros
*/
#define IBS_RANDOM_BITS 12
#define IBS_RANDOM_MASK ((1ULL << IBS_RANDOM_BITS) - 1)
#define IBS_RANDOM_MAXCNT_OFFSET (1ULL << (IBS_RANDOM_BITS - 5))
static u32 get_ibs_caps(void)
{
u32 ibs_caps;
unsigned int max_level;
if (!boot_cpu_has(X86_FEATURE_IBS))
return 0;
/* check IBS cpuid feature flags */
max_level = cpuid_eax(0x80000000);
if (max_level < IBS_CPUID_FEATURES)
return IBS_CAPS_AVAIL;
ibs_caps = cpuid_eax(IBS_CPUID_FEATURES);
if (!(ibs_caps & IBS_CAPS_AVAIL))
/* cpuid flags not valid */
return IBS_CAPS_AVAIL;
return ibs_caps;
}
#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
static void op_mux_fill_in_addresses(struct op_msrs * const msrs)
{
int i;
for (i = 0; i < NUM_VIRT_COUNTERS; i++) {
int hw_counter = op_x86_virt_to_phys(i);
if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
msrs->multiplex[i].addr = MSR_K7_PERFCTR0 + hw_counter;
else
msrs->multiplex[i].addr = 0;
}
}
static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
struct op_msrs const * const msrs)
{
@ -98,7 +127,7 @@ static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
/* enable active counters */
for (i = 0; i < NUM_COUNTERS; ++i) {
int virt = op_x86_phys_to_virt(i);
if (!counter_config[virt].enabled)
if (!reset_value[virt])
continue;
rdmsrl(msrs->controls[i].addr, val);
val &= model->reserved;
@ -107,10 +136,6 @@ static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
}
}
#else
static inline void op_mux_fill_in_addresses(struct op_msrs * const msrs) { }
#endif
/* functions for op_amd_spec */
@ -122,18 +147,12 @@ static void op_amd_fill_in_addresses(struct op_msrs * const msrs)
for (i = 0; i < NUM_COUNTERS; i++) {
if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
msrs->counters[i].addr = MSR_K7_PERFCTR0 + i;
else
msrs->counters[i].addr = 0;
}
for (i = 0; i < NUM_CONTROLS; i++) {
if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i))
msrs->controls[i].addr = MSR_K7_EVNTSEL0 + i;
else
msrs->controls[i].addr = 0;
}
op_mux_fill_in_addresses(msrs);
}
static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
@ -144,7 +163,8 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
/* setup reset_value */
for (i = 0; i < NUM_VIRT_COUNTERS; ++i) {
if (counter_config[i].enabled)
if (counter_config[i].enabled
&& msrs->counters[op_x86_virt_to_phys(i)].addr)
reset_value[i] = counter_config[i].count;
else
reset_value[i] = 0;
@ -152,9 +172,18 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
/* clear all counters */
for (i = 0; i < NUM_CONTROLS; ++i) {
if (unlikely(!msrs->controls[i].addr))
if (unlikely(!msrs->controls[i].addr)) {
if (counter_config[i].enabled && !smp_processor_id())
/*
* counter is reserved, this is on all
* cpus, so report only for cpu #0
*/
op_x86_warn_reserved(i);
continue;
}
rdmsrl(msrs->controls[i].addr, val);
if (val & ARCH_PERFMON_EVENTSEL0_ENABLE)
op_x86_warn_in_use(i);
val &= model->reserved;
wrmsrl(msrs->controls[i].addr, val);
}
@ -169,9 +198,7 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
/* enable active counters */
for (i = 0; i < NUM_COUNTERS; ++i) {
int virt = op_x86_phys_to_virt(i);
if (!counter_config[virt].enabled)
continue;
if (!msrs->counters[i].addr)
if (!reset_value[virt])
continue;
/* setup counter registers */
@ -185,7 +212,60 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
}
}
#ifdef CONFIG_OPROFILE_IBS
/*
* 16-bit Linear Feedback Shift Register (LFSR)
*
* 16 14 13 11
* Feedback polynomial = X + X + X + X + 1
*/
static unsigned int lfsr_random(void)
{
static unsigned int lfsr_value = 0xF00D;
unsigned int bit;
/* Compute next bit to shift in */
bit = ((lfsr_value >> 0) ^
(lfsr_value >> 2) ^
(lfsr_value >> 3) ^
(lfsr_value >> 5)) & 0x0001;
/* Advance to next register value */
lfsr_value = (lfsr_value >> 1) | (bit << 15);
return lfsr_value;
}
/*
* IBS software randomization
*
* The IBS periodic op counter is randomized in software. The lower 12
* bits of the 20 bit counter are randomized. IbsOpCurCnt is
* initialized with a 12 bit random value.
*/
static inline u64 op_amd_randomize_ibs_op(u64 val)
{
unsigned int random = lfsr_random();
if (!(ibs_caps & IBS_CAPS_RDWROPCNT))
/*
* Work around if the hw can not write to IbsOpCurCnt
*
* Randomize the lower 8 bits of the 16 bit
* IbsOpMaxCnt [15:0] value in the range of -128 to
* +127 by adding/subtracting an offset to the
* maximum count (IbsOpMaxCnt).
*
* To avoid over or underflows and protect upper bits
* starting at bit 16, the initial value for
* IbsOpMaxCnt must fit in the range from 0x0081 to
* 0xff80.
*/
val += (s8)(random >> 4);
else
val |= (u64)(random & IBS_RANDOM_MASK) << 32;
return val;
}
static inline void
op_amd_handle_ibs(struct pt_regs * const regs,
@ -194,7 +274,7 @@ op_amd_handle_ibs(struct pt_regs * const regs,
u64 val, ctl;
struct op_entry entry;
if (!has_ibs)
if (!ibs_caps)
return;
if (ibs_config.fetch_enabled) {
@ -236,8 +316,7 @@ op_amd_handle_ibs(struct pt_regs * const regs,
oprofile_write_commit(&entry);
/* reenable the IRQ */
ctl &= ~IBS_OP_VAL & 0xFFFFFFFF;
ctl |= IBS_OP_ENABLE;
ctl = op_amd_randomize_ibs_op(ibs_op_ctl);
wrmsrl(MSR_AMD64_IBSOPCTL, ctl);
}
}
@ -246,41 +325,57 @@ op_amd_handle_ibs(struct pt_regs * const regs,
static inline void op_amd_start_ibs(void)
{
u64 val;
if (has_ibs && ibs_config.fetch_enabled) {
if (!ibs_caps)
return;
if (ibs_config.fetch_enabled) {
val = (ibs_config.max_cnt_fetch >> 4) & 0xFFFF;
val |= ibs_config.rand_en ? IBS_FETCH_RAND_EN : 0;
val |= IBS_FETCH_ENABLE;
wrmsrl(MSR_AMD64_IBSFETCHCTL, val);
}
if (has_ibs && ibs_config.op_enabled) {
val = (ibs_config.max_cnt_op >> 4) & 0xFFFF;
val |= ibs_config.dispatched_ops ? IBS_OP_CNT_CTL : 0;
val |= IBS_OP_ENABLE;
if (ibs_config.op_enabled) {
ibs_op_ctl = ibs_config.max_cnt_op >> 4;
if (!(ibs_caps & IBS_CAPS_RDWROPCNT)) {
/*
* IbsOpCurCnt not supported. See
* op_amd_randomize_ibs_op() for details.
*/
ibs_op_ctl = clamp(ibs_op_ctl, 0x0081ULL, 0xFF80ULL);
} else {
/*
* The start value is randomized with a
* positive offset, we need to compensate it
* with the half of the randomized range. Also
* avoid underflows.
*/
ibs_op_ctl = min(ibs_op_ctl + IBS_RANDOM_MAXCNT_OFFSET,
0xFFFFULL);
}
if (ibs_caps & IBS_CAPS_OPCNT && ibs_config.dispatched_ops)
ibs_op_ctl |= IBS_OP_CNT_CTL;
ibs_op_ctl |= IBS_OP_ENABLE;
val = op_amd_randomize_ibs_op(ibs_op_ctl);
wrmsrl(MSR_AMD64_IBSOPCTL, val);
}
}
static void op_amd_stop_ibs(void)
{
if (has_ibs && ibs_config.fetch_enabled)
if (!ibs_caps)
return;
if (ibs_config.fetch_enabled)
/* clear max count and enable */
wrmsrl(MSR_AMD64_IBSFETCHCTL, 0);
if (has_ibs && ibs_config.op_enabled)
if (ibs_config.op_enabled)
/* clear max count and enable */
wrmsrl(MSR_AMD64_IBSOPCTL, 0);
}
#else
static inline void op_amd_handle_ibs(struct pt_regs * const regs,
struct op_msrs const * const msrs) { }
static inline void op_amd_start_ibs(void) { }
static inline void op_amd_stop_ibs(void) { }
#endif
static int op_amd_check_ctrs(struct pt_regs * const regs,
struct op_msrs const * const msrs)
{
@ -355,8 +450,6 @@ static void op_amd_shutdown(struct op_msrs const * const msrs)
}
}
#ifdef CONFIG_OPROFILE_IBS
static u8 ibs_eilvt_off;
static inline void apic_init_ibs_nmi_per_cpu(void *arg)
@ -405,45 +498,36 @@ static int init_ibs_nmi(void)
return 1;
}
#ifdef CONFIG_NUMA
/* Sanity check */
/* Works only for 64bit with proper numa implementation. */
if (nodes != num_possible_nodes()) {
printk(KERN_DEBUG "Failed to setup CPU node(s) for IBS, "
"found: %d, expected %d",
nodes, num_possible_nodes());
return 1;
}
#endif
return 0;
}
/* uninitialize the APIC for the IBS interrupts if needed */
static void clear_ibs_nmi(void)
{
if (has_ibs)
if (ibs_caps)
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)
{
has_ibs = boot_cpu_has(X86_FEATURE_IBS);
ibs_caps = get_ibs_caps();
if (!has_ibs)
if (!ibs_caps)
return;
if (init_ibs_nmi()) {
has_ibs = 0;
ibs_caps = 0;
return;
}
printk(KERN_INFO "oprofile: AMD IBS detected\n");
printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n",
(unsigned)ibs_caps);
}
static void ibs_exit(void)
{
if (!has_ibs)
if (!ibs_caps)
return;
clear_ibs_nmi();
@ -463,7 +547,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root)
if (ret)
return ret;
if (!has_ibs)
if (!ibs_caps)
return ret;
/* model specific files */
@ -473,7 +557,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root)
ibs_config.fetch_enabled = 0;
ibs_config.max_cnt_op = 250000;
ibs_config.op_enabled = 0;
ibs_config.dispatched_ops = 1;
ibs_config.dispatched_ops = 0;
dir = oprofilefs_mkdir(sb, root, "ibs_fetch");
oprofilefs_create_ulong(sb, dir, "enable",
@ -488,8 +572,9 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root)
&ibs_config.op_enabled);
oprofilefs_create_ulong(sb, dir, "max_count",
&ibs_config.max_cnt_op);
oprofilefs_create_ulong(sb, dir, "dispatched_ops",
&ibs_config.dispatched_ops);
if (ibs_caps & IBS_CAPS_OPCNT)
oprofilefs_create_ulong(sb, dir, "dispatched_ops",
&ibs_config.dispatched_ops);
return 0;
}
@ -507,19 +592,6 @@ static void op_amd_exit(void)
ibs_exit();
}
#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 op_amd_spec = {
.num_counters = NUM_COUNTERS,
.num_controls = NUM_CONTROLS,

View File

@ -394,12 +394,6 @@ static void p4_fill_in_addresses(struct op_msrs * const msrs)
setup_num_counters();
stag = get_stagger();
/* initialize some registers */
for (i = 0; i < num_counters; ++i)
msrs->counters[i].addr = 0;
for (i = 0; i < num_controls; ++i)
msrs->controls[i].addr = 0;
/* the counter & cccr registers we pay attention to */
for (i = 0; i < num_counters; ++i) {
addr = p4_counters[VIRT_CTR(stag, i)].counter_address;

View File

@ -37,15 +37,11 @@ static void ppro_fill_in_addresses(struct op_msrs * const msrs)
for (i = 0; i < num_counters; i++) {
if (reserve_perfctr_nmi(MSR_P6_PERFCTR0 + i))
msrs->counters[i].addr = MSR_P6_PERFCTR0 + i;
else
msrs->counters[i].addr = 0;
}
for (i = 0; i < num_counters; i++) {
if (reserve_evntsel_nmi(MSR_P6_EVNTSEL0 + i))
msrs->controls[i].addr = MSR_P6_EVNTSEL0 + i;
else
msrs->controls[i].addr = 0;
}
}
@ -57,7 +53,7 @@ static void ppro_setup_ctrs(struct op_x86_model_spec const *model,
int i;
if (!reset_value) {
reset_value = kmalloc(sizeof(reset_value[0]) * num_counters,
reset_value = kzalloc(sizeof(reset_value[0]) * num_counters,
GFP_ATOMIC);
if (!reset_value)
return;
@ -82,9 +78,18 @@ static void ppro_setup_ctrs(struct op_x86_model_spec const *model,
/* clear all counters */
for (i = 0; i < num_counters; ++i) {
if (unlikely(!msrs->controls[i].addr))
if (unlikely(!msrs->controls[i].addr)) {
if (counter_config[i].enabled && !smp_processor_id())
/*
* counter is reserved, this is on all
* cpus, so report only for cpu #0
*/
op_x86_warn_reserved(i);
continue;
}
rdmsrl(msrs->controls[i].addr, val);
if (val & ARCH_PERFMON_EVENTSEL0_ENABLE)
op_x86_warn_in_use(i);
val &= model->reserved;
wrmsrl(msrs->controls[i].addr, val);
}

View File

@ -57,6 +57,26 @@ struct op_x86_model_spec {
struct op_counter_config;
static inline void op_x86_warn_in_use(int counter)
{
/*
* The warning indicates an already running counter. If
* oprofile doesn't collect data, then try using a different
* performance counter on your platform to monitor the desired
* event. Delete counter #%d from the desired event by editing
* the /usr/share/oprofile/%s/<cpu>/events file. If the event
* cannot be monitored by any other counter, contact your
* hardware or BIOS vendor.
*/
pr_warning("oprofile: counter #%d on cpu #%d may already be used\n",
counter, smp_processor_id());
}
static inline void op_x86_warn_reserved(int counter)
{
pr_warning("oprofile: counter #%d is already reserved\n", counter);
}
extern u64 op_x86_get_ctrl(struct op_x86_model_spec const *model,
struct op_counter_config *counter_config);
extern int op_x86_phys_to_virt(int phys);

View File

@ -1128,7 +1128,7 @@ config MMAP_ALLOW_UNINITIALIZED
See Documentation/nommu-mmap.txt for more information.
config PROFILING
bool "Profiling support (EXPERIMENTAL)"
bool "Profiling support"
help
Say Y here to enable the extended profiling support mechanisms used
by profilers such as OProfile.