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don't write `rust-prof` bur rather `<toolchain>

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Niko Matsakis 2018-09-07 11:00:09 -04:00 committed by Who? Me?!
parent bb8f906b5d
commit 3d17ee3105
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src/profiling/with_perf.md
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@ -11,7 +11,7 @@ This is a guide for how to profile rustc with [perf](https://perf.wiki.kernel.or
- `use-jemalloc = false` — lets you do memory use profiling with valgrind - `use-jemalloc = false` — lets you do memory use profiling with valgrind
- leave everything else the defaults - leave everything else the defaults
- Run `./x.py build` to get a full build - Run `./x.py build` to get a full build
- Make a rustup toolchain (let's call it `rust-prof`) pointing to that result - Make a rustup toolchain pointing to that result
- see [the "build and run" section for instructions](../how-to-build-and-run.html#toolchain) - see [the "build and run" section for instructions](../how-to-build-and-run.html#toolchain)
## Gathering a perf profile ## Gathering a perf profile
@ -37,10 +37,11 @@ to get call-graph information from debuginfo, which is accurate. The
do: do:
``` ```
perf record -F99 --call-graph dwarf cargo +rust-prof rustc perf record -F99 --call-graph dwarf cargo +<toolchain> rustc
``` ```
to run `cargo`. But there are some things to be aware of: to run `cargo` -- here `<toolchain>` should be the name of the toolchain
you made in the beginning. But there are some things to be aware of:
- You probably don't want to profile the time spend building - You probably don't want to profile the time spend building
dependencies. So something like `cargo build; cargo clean -p $C` may dependencies. So something like `cargo build; cargo clean -p $C` may
@ -77,10 +78,13 @@ build the dependencies:
```bash ```bash
# Setup: first clean out any old results and build the dependencies: # Setup: first clean out any old results and build the dependencies:
> cargo +rust-prof clean > cargo +<toolchain> clean
> CARGO_INCREMENTAL=0 cargo +rust-prof check > CARGO_INCREMENTAL=0 cargo +<toolchain> check
``` ```
(Again, `<toolchain>` should be replaced with the name of the
toolchain we made in the first step.)
Next: we want record the execution time for *just* the clap-rs crate, Next: we want record the execution time for *just* the clap-rs crate,
running cargo check. I tend to use `cargo rustc` for this, since it running cargo check. I tend to use `cargo rustc` for this, since it
also allows me to add explicit flags, which we'll do later on. also allows me to add explicit flags, which we'll do later on.