Oprofile分析（android oprofile性能分析）

一、内核支持：
make menuconfig

1、评测菜单中启用 Oprofile ，在 .config 文件中设置?CONFIG_PROFILING=y?和?CONFIG_OPROFILE=y
2、Kernel Feature->[]Enable hardware performance counter support for perf events不要勾选
3、在boot options->console=ttyFIQ0 androidboot.console=ttyFIQ0 init=/init profile=1
二、修改源码 将kernel/arch/arm/oprofile中的common.文件修改

/**                                
 * @file common.c                                
 *                                
 * @remark Copyright 2004 Oprofile Authors                                
 * @remark Copyright 2010 ARM Ltd.                                
 * @remark Read the file COPYING                                
 *                                
 * @author Zwane Mwaikambo                                
 * @author Will Deacon [move to perf]                                
 */                                
                                
#include <linux/cpumask.h>                                
#include <linux/err.h>                                
#include <linux/errno.h>                                
#include <linux/init.h>                                
#include <linux/mutex.h>                                
#include <linux/oprofile.h>                                
#include <linux/perf_event.h>                                
#include <linux/platform_device.h>                                
#include <linux/slab.h>                                
#include <asm/stacktrace.h>                                
#include <linux/uaccess.h>                                
                                
#include <asm/perf_event.h>                                
#include <asm/ptrace.h>                                
                                
#ifdef CONFIG_HW_PERF_EVENTS                                
/*                                
 * Per performance monitor configuration as set via oprofilefs.                                
 */                                
struct op_counter_config {                                
    unsigned long count;                            
    unsigned long enabled;                            
    unsigned long event;                            
    unsigned long unit_mask;                            
    unsigned long kernel;                            
    unsigned long user;                            
    struct perf_event_attr attr;                            
};                                
                                
static int op_arm_enabled;                                
static DEFINE_MUTEX(op_arm_mutex);                                
                                
static struct op_counter_config *counter_config;                                
static struct perf_event **perf_events[nr_cpumask_bits];                                
static int perf_num_counters_bak;                                
                                
/*                                
 * Overflow callback for oprofile.                                
 */                                
static void op_overflow_handler(struct perf_event *event, int unused,                                
            struct perf_sample_data *data, struct pt_regs *regs)                    
{                                
    int id;                            
    u32 cpu = smp_processor_id();                            
                                
    for (id = 0; id < perf_num_counters_bak; ++id)                            
        if (perf_events[cpu][id] == event)                        
            break;                    
                                
    if (id != perf_num_counters_bak)                            
        oprofile_add_sample(regs, id);                        
    else                            
        pr_warning("oprofile: ignoring spurious overflow "                        
                on cpu %u
, cpu);                
}                                
                                
/*                                
 * Called by op_arm_setup to create perf attributes to mirror the oprofile                                
 * settings in counter_config. Attributes are created as `pinned' events and                                
 * so are permanently scheduled on the PMU.                                
 */                                
static void op_perf_setup(void)                                
{                                
    int i;                            
    u32 size = sizeof(struct perf_event_attr);                            
    struct perf_event_attr *attr;                            
                                
    for (i = 0; i < perf_num_counters_bak; ++i) {                            
        attr = &counter_config[i].attr;                        
        memset(attr, 0, size);                        
        attr->type        = PERF_TYPE_RAW;                
        attr->size        = size;                
        attr->config        = counter_config[i].event;                
        attr->sample_period    = counter_config[i].count;                    
        attr->pinned        = 1;                
    }                            
}                                
                                
static int op_create_counter(int cpu, int event)                                
{                                
    int ret = 0;                            
    struct perf_event *pevent;                            
                                
    if (!counter_config[event].enabled || (perf_events[cpu][event] != NULL))                            
        return ret;                        
                                
    pevent = perf_event_create_kernel_counter(&counter_config[event].attr,                            
                          cpu, NULL,        
                          op_overflow_handler);        
                                
    if (IS_ERR(pevent)) {                            
        ret = PTR_ERR(pevent);                        
    } else if (pevent->state != PERF_EVENT_STATE_ACTIVE) {                            
        pr_warning("oprofile: failed to enable event %d "                        
                on CPU %d
, event, cpu);                
        ret = -EBUSY;                        
    } else {                            
        perf_events[cpu][event] = pevent;                        
    }                            
                                
    return ret;                            
}                                
                                
static void op_destroy_counter(int cpu, int event)                                
{                                
    struct perf_event *pevent = perf_events[cpu][event];                            
                                
    if (pevent) {                            
        perf_event_release_kernel(pevent);                        
        perf_events[cpu][event] = NULL;                        
    }                            
}                                
                                
/*                                
 * Called by op_arm_start to create active perf events based on the                                
 * perviously configured attributes.                                
 */                                
static int op_perf_start(void)                                
{                                
    int cpu, event, ret = 0;                            
                                
    for_each_online_cpu(cpu) {                            
        for (event = 0; event < perf_num_counters_bak; ++event) {                        
            ret = op_create_counter(cpu, event);                    
            if (ret)                    
                goto out;                
        }                        
    }                            
                                
out:                                
    return ret;                            
}                                
                                
/*                                
 * Called by op_arm_stop at the end of a profiling run.                                
 */                                
static void op_perf_stop(void)                                
{                                
    int cpu, event;                            
                                
    for_each_online_cpu(cpu)                            
        for (event = 0; event < perf_num_counters_bak; ++event)                        
            op_destroy_counter(cpu, event);                    
}                                
                                
char *op_name_from_perf_id(void)                                
{                                
    enum arm_perf_pmu_ids id = armpmu_get_pmu_id();                            
                                
    switch (id) {                            
    case ARM_PERF_PMU_ID_XSCALE1:                            
        return "arm/xscale1";                        
    case ARM_PERF_PMU_ID_XSCALE2:                            
        return "arm/xscale2";                        
    case ARM_PERF_PMU_ID_V6:                            
        return "arm/armv6";                        
    case ARM_PERF_PMU_ID_V6MP:                            
        return "arm/mpcore";                        
    case ARM_PERF_PMU_ID_CA8:                            
        return "arm/armv7";                        
    case ARM_PERF_PMU_ID_CA9:                            
        return "arm/armv7-ca9";                        
    default:                            
        return NULL;                        
    }                            
}                                
                                
static int op_arm_create_files(struct super_block *sb, struct dentry *root)                                
{                                
    unsigned int i;                            
                                
    for (i = 0; i < perf_num_counters_bak; i++) {                            
        struct dentry *dir;                        
        char buf[4];                        
                                
        snprintf(buf, sizeof buf, "%d", i);                        
        dir = oprofilefs_mkdir(sb, root, buf);                        
        oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);                        
        oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);                        
        oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);                        
        oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);                        
        oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);                        
        oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);                        
    }                            
                                
    return 0;                            
}                                
                                
static int op_arm_setup(void)                                
{                                
    spin_lock(&oprofilefs_lock);                            
    op_perf_setup();                            
    spin_unlock(&oprofilefs_lock);                            
    return 0;                            
}                                
                                
static int op_arm_start(void)                                
{                                
    int ret = -EBUSY;                            
                                
    mutex_lock(&op_arm_mutex);                            
    if (!op_arm_enabled) {                            
        ret = 0;                        
        op_perf_start();                        
        op_arm_enabled = 1;                        
    }                            
    mutex_unlock(&op_arm_mutex);                            
    return ret;                            
}                                
                                
static void op_arm_stop(void)                                
{                                
    mutex_lock(&op_arm_mutex);                            
    if (op_arm_enabled)                            
        op_perf_stop();                        
    op_arm_enabled = 0;                            
    mutex_unlock(&op_arm_mutex);                            
}                                
                                
#ifdef CONFIG_PM                                
static int op_arm_suspend(struct platform_device *dev, pm_message_t state)                                
{                                
    mutex_lock(&op_arm_mutex);                            
    if (op_arm_enabled)                            
        op_perf_stop();                        
    mutex_unlock(&op_arm_mutex);                            
    return 0;                            
}                                
                                
static int op_arm_resume(struct platform_device *dev)                                
{                                
    mutex_lock(&op_arm_mutex);                            
    if (op_arm_enabled && op_perf_start())                            
        op_arm_enabled = 0;                        
    mutex_unlock(&op_arm_mutex);                            
    return 0;                            
}                                
                                
static struct platform_driver oprofile_driver = {                                
    .driver        = {                    
        .name        = "arm-oprofile",                
    },                            
    .resume        = op_arm_resume,                    
    .suspend    = op_arm_suspend,                        
};                                
                                
static struct platform_device *oprofile_pdev;                                
                                
static int __init init_driverfs(void)                                
{                                
    int ret;                            
                                
    ret = platform_driver_register(&oprofile_driver);                            
    if (ret)                            
        goto out;                        
                                
    oprofile_pdev =    platform_device_register_simple(                        
                oprofile_driver.driver.name, 0, NULL, 0);                
    if (IS_ERR(oprofile_pdev)) {                            
        ret = PTR_ERR(oprofile_pdev);                        
        platform_driver_unregister(&oprofile_driver);                        
    }                            
                                
out:                                
    return ret;                            
}                                
                                
static void  exit_driverfs(void)                                
{                                
    platform_device_unregister(oprofile_pdev);                            
    platform_driver_unregister(&oprofile_driver);                            
}                                
#else                                
static int __init init_driverfs(void) { return 0; }                                
#define exit_driverfs() do { } while (0)                                
#endif /* CONFIG_PM */                                
                                
static int report_trace(struct stackframe *frame, void *d)                                
{                                
    unsigned int *depth = d;                            
                                
    if (*depth) {                            
        oprofile_add_trace(frame->pc);                        
        (*depth)--;                        
    }                            
                                
    return *depth == 0;                            
}                                
                                
/*                                
 * The registers we're interested in are at the end of the variable                                
 * length saved register structure. The fp points at the end of this                                
 * structure so the address of this struct is:                                
 * (struct frame_tail *)(xxx->fp)-1                                
 */                                
struct frame_tail {                                
    struct frame_tail *fp;                            
    unsigned long sp;                            
    unsigned long lr;                            
} __attribute__((packed));                                
                                
static struct frame_tail* user_backtrace(struct frame_tail *tail)                                
{                                
    struct frame_tail buftail[2];                            
                                
    /* Also check accessibility of one struct frame_tail beyond */                            
    if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))                            
        return NULL;                        
    if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))                            
        return NULL;                        
                                
    oprofile_add_trace(buftail[0].lr);                            
                                
    /* frame pointers should strictly progress back up the stack                            
     * (towards higher addresses) */                            
    if (tail + 1 >= buftail[0].fp)                            
        return NULL;                        
                                
    return buftail[0].fp-1;                            
}                                
                                
static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)                                
{                                
    struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;                            
                                
    if (!user_mode(regs)) {                            
        struct stackframe frame;                        
        frame.fp = regs->ARM_fp;                        
        frame.sp = regs->ARM_sp;                        
        frame.lr = regs->ARM_lr;                        
        frame.pc = regs->ARM_pc;                        
        walk_stackframe(&frame, report_trace, &depth);                        
        return;                        
    }                            
                                
    while (depth-- && tail && !((unsigned long) tail & 3))                            
        tail = user_backtrace(tail);                        
}                                
                                
int __init oprofile_arch_init(struct oprofile_operations *ops)                                
{                                
    int cpu, ret = 0;                            
                                
    perf_num_counters_bak = armpmu_get_max_events();                            
                                
    counter_config = kcalloc(perf_num_counters_bak,                            
            sizeof(struct op_counter_config), GFP_KERNEL);                    
                                
    if (!counter_config) {                            
        pr_info("oprofile: failed to allocate %d "                        
                counters
, perf_num_counters_bak);                
        return -ENOMEM;                        
    }                            
                                
    ret = init_driverfs();                            
    if (ret) {                            
        kfree(counter_config);                        
        return ret;                        
    }                            
                                
    for_each_possible_cpu(cpu) {                            
        perf_events[cpu] = kcalloc(perf_num_counters_bak,                        
                sizeof(struct perf_event *), GFP_KERNEL);                
        if (!perf_events[cpu]) {                        
            pr_info("oprofile: failed to allocate %d perf events "                    
                    for cpu %d
, perf_num_counters_bak, cpu);            
            while (--cpu >= 0)                    
                kfree(perf_events[cpu]);                
            return -ENOMEM;                    
        }                        
    }                            
                                
    ops->backtrace        = arm_backtrace;                    
    ops->create_files    = op_arm_create_files;                        
    ops->setup        = op_arm_setup;                    
    ops->start        = op_arm_start;                    
    ops->stop        = op_arm_stop;                    
    ops->shutdown        = op_arm_stop;                    
    ops->cpu_type        = op_name_from_perf_id();                    
                                
    if (!ops->cpu_type)                            
        ret = -ENODEV;                        
    else                            
        pr_info("oprofile: using %s
", ops->cpu_type);                        
                                
    return ret;                            
}                                
                                
void oprofile_arch_exit(void)                                
{                                
    int cpu, id;                            
    struct perf_event *event;                            
                                
    if (*perf_events) {                            
        exit_driverfs();                        
        for_each_possible_cpu(cpu) {                        
            for (id = 0; id < perf_num_counters_bak; ++id) {                    
                event = perf_events[cpu][id];                
                if (event != NULL)                
                    perf_event_release_kernel(event);            
            }                    
            kfree(perf_events[cpu]);                    
        }                        
    }                            
                                
    if (counter_config)                            
        kfree(counter_config);                        
}                                
                                
#else                                
int __init oprofile_arch_init(struct oprofile_operations *ops)                                
{                                
    pr_info("oprofile: hardware counters not available
");                            
    return -ENODEV;                            
}                                
void oprofile_arch_exit(void) {}                                
#endif /* CONFIG_HW_PERF_EVENTS */

三、相关
kernel/sched.c--------profile_hit(SCHED_PROFILING, __builtin_return_address(0));
下面是对profile的解释：Linux -- profile内核版本2.6.18-RC7
profile只是内核的一个调试性能的工具，这个可以通过menuconfig中的Instrumentation Support->profile打开。
1. 如何使用profile：
首先确认内核支持profile，然后在内核启动时加入以下参数：profile=1或者其它参数， 新的内核支持profile=schedule 1
2. 内核启动后会创建/proc/profile文件，这个文件可以通过readprofile读取，
如readprofile -m /proc/kallsyms | sort -nr > ~/cur_profile.log,
或者readprofile -r -m /proc/kallsyms |sort -nr,
或者readprofile -r && sleep 1 && readprofile -m /proc/kallsyms |sort -nr >~/cur_profile.log
3. 读取/proc/profile可获得哪些内容？
根据启动配置profile＝？的不同，获取的内容不同：
如果配置成profile=? 可以获得每个函数执行次数，用来调试函数性能很有用
如果设置成profile=schedule ?可以获得每个函数调用schedule的次数，用来调试schedule很有用

四、总结一下：
opcontrol –init 加载模块， mout /dev/oprofile 创建必需的文件和目录
opcontrol --no-vmlinux 或者 opcontrol --vmlinux=/boot/vmlinux-`uname -r` 决定是否对 kernel 进行 profiling
opcontrol --list-events //命令可以查看此结构中支持的事件
opcontrol --event=CPU_CLK_UNHALTED:5000 --event=DATA_CACHE_MISSES:1000 --event=INSTRUCTION_CACHE_MISSES:1000 --event=MEMORY_REQUESTS:1000
opcontrol --reset 清楚当前会话中的数据
opcontrol --start 开始 profiling
./wls 运行应用程序， oprofile 会对它进行 profiling 通过opcontrol --event=L2_CACHE_MISS:500 --event=L1_DTLB_MISS_AND_L2_DTLB_HIT:500
opcontrol --dump 把收集到的数据写入文件 --event=.........命令来进行事件的设置；
opcontrol --stop 停止 profiling 此命令--event参数必须依次给出，无论有多少个，不可分行，切记
opcotrol -h 关闭守护进程 oprofiled
opcontrol --shutdown 停止 oprofiled
opcontrol --deinit 卸载模块

常用的是 3→7 这几个过程，得到性能数据之后，可以使用 opreport, opstack, opgprof, opannotate几个工具进行分析，我常用的是
opreport, opannotate 进行分析。

五、示例与常见问题解诀
Command format :$:tager board, #:Host
1.Extract opf.tar.gz and busybox.tar.gz ($: tar -zxvf ***.tar.gz)
2.Use adb push opf to /data/opf and busybox to /data/busybox
(#: adb push opf /data/opf and #: adb push busybox /data/busybox)
3.Run $:export PATH=$PATH:/data/opf

$: is command to begin
4.Run $:opcontrol --init

Remark: if target board have oprofile,please delete the files(path:/system/xbin)

Question:
grep: /etc/mtab: No such file or directory
grep: /etc/mtab: No such file or directory
Kernel support not available, missing opcontrol --init as root

Answer:
a.$:mount -o remount rw /
b.$:mount -o rw,remount -t yaffs2 /dev/block/mmcblk0p9 /system
c.$:touch /system/etc/mtab or touch /etc/mtab
d.$:echo nodev /dev/oprofile oprofilefs rw 0 0 > /system/etc/mtab or /etc/mtab
e.make sure mtab the nodev $:cat /system/etc/mtab

5.$:opcontrol --init

Question:
cat: can't open '/dev/oprofile/cpu_type': No such file or directory
Unable to open cpu_type file for reading
Make sure you have done opcontrol --init
cpu_type 'unset' is not valid
you should upgrade oprofile or force the use of timer mode

Answer:
a.$:mkdir /dev/oprofile (if not exist)
b.mount -t oprofilefs nodev /dev/oprofile

6.$:opcontrol --session-dir=/data/first --no-vmlinux --callgraph=5

7.$:opcontrol --start

Question:
oprofile: could not open unit mask description file /home/henry/workspace/opf/pc/build/oprofile/share/oprofile//arm/armv7-ca9/unit_masks
Using default event: CPU_CYCLES:100000:0:1:1
oprofile: could not open unit mask description file /home/henry/workspace/opf/pc/build/oprofile/share/oprofile//arm/armv7-ca9/unit_masks

Answer:
a.To target board running $:mkdir -p /home/henry/workspace/opf/pc/build/oprofile
b.Extract share.tar.gz
c.Use ADB push share (#:adb push share /home/henry/workspace/opf/pc/build/oprofile/share)

8.Run App to profile
9.$:opcontrol --dump
10.$:opcontrol --stop
11.$:opreport --session-dir=/data/first -l /data/test/test
$:opreport --session-dir=/data/first -l >log
$:opreport --session-dir=/data/first -l /data/data/Service/lib/libXXX.so >logXXX
$:opreport --session-dir=/data/first -l /data/data/Service/lib/libBBB.so >logBBB
12.$:opcontrol --reset
13.opcontrol --shutdown

Remark: $:opcontrol --shutdown and $:opcontrol --init only execution once