oprofile相关

问题：Make sure you are using the non-compressed imag

问题：Make sure you are using the non-compressed image file

问题现象：

# ./opcontrol --setup --vmlinux=/edwin/kernel/linux-2.6.18_pro500/vmlinux
The specified file /edwin/kernel/linux-2.6.18_pro500/vmlinux does not seem to be valid
Make sure you are using the non-compressed image file (e.g. vmlinux not vmlinuz)


解决方法：

分析：
参看源码，由于在指定内核镜像时，会用到objdump 应用程序检测镜像中的.text段内容,而在JK2410板子上面没有交叉编译的objdump应用程序，所以不能通过判断，以至于，即使指定的是未压缩的内核镜像，也被误认为压缩的了。

动作：
将arm-9tdmi-linu-gnu交叉编译器目录下的objdump 拷贝到 JK2410开发板的/usr/bin目录下

Host:
# cp /work/binutils/binutils-2.17-install-dir/arm-9tdmi-linux-gnu/bin/objdump
/work

Target:
# cp /edwin/objdump /usr/bin

或者直接将 objdump 作到根文件系统里面


Profiling the kernel image "Vmlinux"

步骤：
# ./opcontrol --init

# ./opcontrol --vmlinux=/edwin/kernel/linux-2.6.18_pro500/vmlinux
Using 2.6+ OProfile kernel interface.
Reading module info.
Using log file /var/lib/oprofile/samples/oprofiled.log
Daemon started.
Profiler running.

# ./opcontrol --dump

# ./opreport
./opreport error: No sample file found: try running opcontrol --dump
or specify a session containing sample files
如果打印出上面的信息，并不是说明oprofile没有工作，或者配置有问题，实际上是因为在vmvare machine上，oprofile采用时钟中断的方式采样数据，可以等时间长一点，或者多敲一些命令。然后再执行
# ./opcontrol --dump
# ./opreport

得到如下分析结果：

# ./opreport

CPU: CPU with timer interrupt, speed 0 MHz (estimated)
Profiling through timer interrupt
TIMER:0|
samples|
%|
------------------
33278 99.0535 vmlinux
182    0.5417 ld-linux.so.2
63     0.1875 libc.so.6
57     0.1697 busybox
8      0.0238 libstdc++.so.6.0.1
4      0.0119 opreport
2      0.0060 libgcc_s.so.1
1      0.0030 opgprof
1      0.0030 libcrypt-2.3.3.so



获得更加详细的信息
# ./opreport -l /edwin/kernel/linux-2.6.18_pro500/vmlinux

CPU: CPU with timer interrupt, speed 0 MHz (estimated)
Profiling through timer interrupt
samples
%

symbol name
706796
99.6478
default_idle
276
0.0389
net_interrupt
126
0.0178
arm920_flush_user_cache_range
113
0.0159
__schedule
59
0.0083
update_mmu_cache
45
0.0063
v4wb_copy_user_page
43
0.0061
netif_rx
42
0.0059
__copy_to_user
41
0.0058
__queue_work
37
0.0052
net_send_packet
33
0.0047
__handle_mm_fault
30
0.0042
udp_sendmsg
29
0.0041
flush_dcache_page
27
0.0038
__memzero
27
0.0038
unmap_vmas
23
0.0032
ip_append_data
20
0.0028
__rcu_read_unlock
20
0.0028
handle_IRQ_event
19
0.0027
__rcu_read_lock
19
0.0027
process_backlog
19
0.0027
xdr_decode_fattr
18
0.0025
kmem_cache_free
17
0.0024
__link_path_walk
17
0.0024
kmem_cache_alloc
17
0.0024
ksoftirqd
17
0.0024
local_bh_enable
16
0.0023
__rpc_execute
16
0.0023
arm920_flush_kern_dcache_page
15
0.0021
__kmalloc
15
0.0021
call_transmit
15
0.0021
do_irqd
14
0.0020
__alloc_skb
14
0.0020
__d_lookup
14
0.0020
__dabt_usr
14
0.0020
__udivsi3
14
0.0020
csum_partial_copy_nocheck
14
0.0020
find_get_page
14
0.0020
get_page_from_freelist
14
0.0020
ip_route_input
14
0.0020
memcmp
14
0.0020
nfs_refresh_inode
14
0.0020
notifier_call_chain
14
0.0020
rpc_wake_up_next
13
0.0018
ip_push_pending_frames



……