NEW BOT Телеграм, страница

Server Select Tool for the hide.me Linux CLI client
https://redd.it/1mo0vqe
@r_bash

6 views06:15

timep: a next-gen time-profiler and flamegraph-generator for bash code

`timep` is a **time p**rofiler for bash code that will give you a per-command execution time breakdown of any bash noscript or function.

Unlike other profilers, `timep` records both wall-clock time and cpu time (via a loadable builtin that is base64 encoded in the noscript and automatically sets itself up when you source timep.bash). Also unlike other profilers, `timep also recovers and hierarchially records metadata on subshell and function nesting, allowing it to recreate the full call-stack tree for that bash code.

***

**BASH-NATIVE FLAMEGRAPHS**

If you call `timep` with the `--flame` flag, it will automatically generate a BASH-NATIVE flamegraph .noscript image (where each top-level block represents the wall-clock time spent on a particular command, and all the lower level blocks represent the combined time spent in the parent subshells/functions...this is not a perf flamegraph showing syscalls). Furthermore, Ive added a new colorscheme to the flamegraph generation noscript that will:

1. color things that take up more time with hotter colors (normal flamegraph coloring is "random but consistent for a given function name")
2. desaturate commands with low cpu time/ wall time ratio (e.g., wait, sleep, blocking reads, etc)
3. empirically remap the colors using a runtime-weighted CDF so that the colorscale is evenly used in the flamegraph and so extremes dont dominate the coloring
4. multiple flamegraphs are stacked vertically in the same noscript image.

[HERE](https://raw.githubusercontent.com/jkool702/timep/main/TESTS/FORKRUN/flamegraphs/flamegraph.ALL.noscript) is an example of what they look like (details near the bottom of this post).

***

**USAGE**

To use `timep`, download and source the `timep.bash` file from the github repo, then just add `timep` before whatever you want to profile. `timep` handles everything else, including (when needed) redirecting stdin to whatever is being profiled. ZERO changes need to be made to the code you want to profile. Example usage:

. timep.bash
timep someFunc <input_file
timep --flame /path/to/someScript.bash
timep -c 'command1' 'command2'

`timep` will create 2 time profiles for you - one that has every single command and full metadata, and one that combines commands repeated in loops and only shows run count + total runtime for each command. By default the 2nd one is shown, but this is configurable via thge '-o' flag and both profiles are always saved to disk.

For more info refer to the README on github and the comments at the top of timep.bash.

**DEPENDENCIES**: the major dependencies are bash 5+ and a mounted procfs. Various common commandline tools (sed, grep, cat, tail, ...) are required as well. This basically means you have to be running linux for timep to work.

* bash 5+ is required because timep fundamentally works by recording `$EPOCHREALTIME` timestamps. In theory you could probably replace each `${EPOCHREALTIME}` with `$(date +"%s.%6N")` to get it to run at bash 4, but it would be considerably less accurate and less efficient.
* mounted procfs it required to read several things (PPID, PGID, TPID, CTTY, PCOMM) from `/proc/<pid>/stat`. `timep` needs these to correctly re-create the call-stack tree. It *might* be possible to get these things from external tools, which would (at the cost of efficiency) allow `timep` to be used outsude of linux. But this would be a considerable undertaking.

***

**EXAMPLES**

Heres an example of the type of output timep generates.

```
testfunc() { f() { echo "f: $*"; }
g() ( echo "g: $*"; )
h() { echo "h: $*"; ff "$@"; gg "$@"; }
echo 0
{ echo 1; }
( echo 2 )
echo 3 &
{ echo 4; } &
echo 5 | cat | tee
for (( kk=6; kk<10; kk++ )); do
echo $kk
h $kk
for jj in {1..3}; do
f $kk $jj
g $kk $jj
done
done
}
timep testfunc

gives

LINE.DEPTH.CMD NUMBER COMBINED WALL-CLOCK TIME COMBINED CPU TIME COMMAND

4 views07:15