how to filter unnecessary info from stap output?

[ch huang]

i want observer ext module action, i write the following script


# cat exec.stp -o file
probe module("ext3").function("*").call {
printf("%s -> %s\n", thread_indent(1), probefunc())
}
probe module("ext3").function("*").return {
printf("%s <- %s\n", thread_indent(-1), probefunc())
}

but i want stap output in file,when i run like 'echo "aaa" > ufile '
command ,not always flood the output file with like
'   10 pdflush(32612): <- ext3_write_super
     0 pdflush(32612): -> ext3_write_inode
     4 pdflush(32612): <- ext3_write_inode
     0 pdflush(32612): -> ext3_write_inode
     3 pdflush(32612): <- ext3_write_inode
     0 pdflush(32612): -> ext3_write_inode
     3 pdflush(32612): <- ext3_write_inode
     0 pdflush(32612): -> ext3_write_inode
     3 pdflush(32612): <- ext3_write_inode ' such unnecessary info ,any help?