• Steven Rostedt (VMware)'s avatar
    ftrace: Create separate t_func_next() to simplify the function / hash logic · 5bd84629
    Steven Rostedt (VMware) authored
    I noticed that if I use dd to read the set_ftrace_filter file that the first
    hash command is repeated.
    
     # cd /sys/kernel/debug/tracing
     # echo schedule > set_ftrace_filter
     # echo do_IRQ >> set_ftrace_filter
     # echo schedule:traceoff >> set_ftrace_filter
     # echo do_IRQ:traceoff >> set_ftrace_filter
    
     # cat set_ftrace_filter
     schedule
     do_IRQ
     schedule:traceoff:unlimited
     do_IRQ:traceoff:unlimited
    
     # dd if=set_ftrace_filter bs=1
     schedule
     do_IRQ
     schedule:traceoff:unlimited
     schedule:traceoff:unlimited
     do_IRQ:traceoff:unlimited
     98+0 records in
     98+0 records out
     98 bytes copied, 0.00265011 s, 37.0 kB/s
    
    This is due to the way t_start() calls t_next() as well as the seq_file
    calls t_next() and the state is slightly different between the two. Namely,
    t_start() will call t_next() with a local "pos" variable.
    
    By separating out the function listing from t_next() into its own function,
    we can have better control of outputting the functions and the hash of
    triggers. This simplifies the code.
    Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
    5bd84629
ftrace.c 146 KB