When I use this function funcslower found to function funclatency more specific compared to the time when a function for those who want to know the execution time of the distribution,
Using funclatency is a good choice, but for the time when anxious to know the system a function to be executed, and then use funcslower easy enough.
funcslower literally, the function of those slow, in short, to correct the system, those who call execution time exceeds a set value.
This feature may be that you upon a variety of systems analysis tools are ineffective, as the final diagnostic tool for the analysis of system performance issues.
The old way, talking about the help.
usage: funcslower [-hf] [-p PID] [-U | -K] [-m MIN_MS] [-u MIN_US] [-a ARGUMENTS] [-T] [-t] [-v] function [function ...] Trace slow kernel or user function calls. positional arguments: function function(s) to trace optional arguments: -h, --help show this help message and exit -p PID, --pid PID trace this PID only -m MIN_MS, --min-ms MIN_MS # 执行时间低于xx毫秒，作为阈值 minimum duration to trace (ms) -u MIN_US, --min-us MIN_US minimum duration to trace (us) # execution time is longer than xx us, as the threshold value -U, --user- Stack Show User Space # Stacks from user mode stack calls display information -K, --kernel- Stack Show Stacks from Kernel Space # call stack information display kernel mode -f Print Output in Folded stack # think the format can be considered for a flame FIG. -a aRGUMENTS, - arguments aRGUMENTS Print the this entry MANY arguments, parameters input print # AS hex, decimal installation way -T, - Time show HH: MM: SS # display timestamp timestamp -t, --timestamp show timestamp in seconds the AT US Resolution # display a time stamp, in the form of seconds -v, --verbose Print at The BPF Program for the debugging Purposes # display the function call information
./funcslower c:open -u 1
1us delay the operation process open function to perform statistical system
./Funcslower c #: Open -u 1 Tracing function Calls It would help Within last 1 US ... Ctrl + C # to quit. COMM represents instructions executed COMM PID LAT (US) RVAL FUNC less 27074 33.77 3 c: Open less 27074 9.96 C FFFFFFFFFFFFFFFF: Open less 27 074 5.92 FFFFFFFFFFFFFFFF C: Open less 27 074 15.88 FFFFFFFFFFFFFFFF C: Open less 27 074 8.89 . 3 C: Open less 27074 15.89 . 3 C: Open SH 27075 20.97 4 c:open bash 27075 20.14 4 c:open
Note that: fffffff appear above other content was open function returns the value RVAL operation fails, it returns -1;
./funcslower -m 10 vfs_read
Shows only processes vfs_read function call execution time of more than 10ms
Tracing function calls slower than 10 ms... Ctrl+C to quit. COMM PID LAT(ms) RVAL FUNC bash 11527 78.97 1 vfs_read bash 11527 101.26 1 vfs_read bash 11527 1053.60 1 vfs_read bash 11527 44.21 1 vfs_read
./funcslower __kmalloc -a 2 -u 1
Displaying the execution time of the operation process __kmalloc 1us, and prints out the first two parameters of the function passed to each process.
Tracing function calls slower than 1 us... Ctrl+C to quit. COMM PID LAT(us) RVAL FUNC ARGS kworker/0:2 27077 7.46 ffff90054f9f8e40 __kmalloc 0x98 0x1400000 kworker/0:2 27077 6.84 ffff90054f9f8e40 __kmalloc 0x98 0x1400000 bash 11527 6.87 ffff90054f9f8e40 __kmalloc 0x90 0x1408240 bash 11527 1.15 ffff90054f9f8e40 __kmalloc 0x90 0x1408240 bash 11527 1.15 ffff90055a1b8c00 __kmalloc 0x2c 0x1400240 bash 11527 1.18 ffff90054b87d240 __kmalloc 0x1c 0x1400040
./funcslower -U -m 30 '/usr/sbin/nginx:database_write'
A function for tracking a certain type of special case inside the program execution time of more than 30ms process and print their user mode stack information.
Tracing function calls slower than 30 ms... Ctrl+C to quit. COMM PID LAT(ms) RVAL FUNC nginx 1617 30.15 9 /usr/sbin/nginx:database_write DataBaseProvider::setData(std::string const&, record_s&) UserDataProvider::saveRecordData(RecordData const&) RequestProcessor::writeResponse(int) RequestProcessor::processRequest() RequestRouter::processRequest(RequestWrapper*, ResponseWrapper*) ngx_http_core_content_phase ngx_http_core_run_phases ngx_http_process_request ngx_process_events_and_timers ngx_spawn_process ngx_master_process_cycle main __libc_start_main [unknown]