Counting Function Calls Made
script examples
tallying function calls
examples of SystemTap scripts
tallying function calls
tallying function calls
examples of SystemTap scripts
counting function calls
examples of SystemTap scripts
function calls, tallying
examples of SystemTap scripts
WAR STORY: Function call count http://sourceware.org/systemtap/wiki/WSFunctionCallCount?highlight=((WarStories))
no script in examples
This section describes how to identify how many times the system called a specific kernel function in a 30-second sample. Depending on your use of wildcards, you can also use this script to target multiple kernel functions.
functioncallcount.stp
takes the targeted kernel function as an argument. The argument supports wildcards, which enables you to target multiple kernel functions up to a certain extent.
script examples
timer.ms(), sample usage
examples of SystemTap scripts
timer.ms(), sample usage
timer.ms(), sample usage
examples of SystemTap scripts
You can increase the sample time by editing the timer in the second probe (timer.ms()). The output of contains the name of the function called and how many times it was called during the sample time (in alphabetical order). contains an excerpt from the output of stap countcalls.stp "*@mm/*.c":
Sample Output
[...]
__vma_link 97
__vma_link_file 66
__vma_link_list 97
__vma_link_rb 97
__xchg 103
add_page_to_active_list 102
add_page_to_inactive_list 19
add_to_page_cache 19
add_to_page_cache_lru 7
all_vm_events 6
alloc_pages_node 4630
alloc_slabmgmt 67
anon_vma_alloc 62
anon_vma_free 62
anon_vma_lock 66
anon_vma_prepare 98
anon_vma_unlink 97
anon_vma_unlock 66
arch_get_unmapped_area_topdown 94
arch_get_unmapped_exec_area 3
arch_unmap_area_topdown 97
atomic_add 2
atomic_add_negative 97
atomic_dec_and_test 5153
atomic_inc 470
atomic_inc_and_test 1
[...]