Recommend the extra interface by default

doc/yjit/yjit.md

@@ -479,19 +479,9 @@ perf script --fields +pid > /tmp/test.perf
 
 You can also profile the number of cycles consumed by code generated by each YJIT function.
 
-#### Using perf with Python support
-
-`misc/yjit_perf.py` is a script for `perf script -s` command.
-By default, it doesn't support Python scripts, so you need to build `perf` from source.
-
 ```bash
-# Build perf from source for Python support
-sudo apt-get install libpython3-dev python3-pip flex libtraceevent-dev \
-  libelf-dev libunwind-dev libaudit-dev libslang2-dev libdw-dev
-git clone --depth=1 https://github.com/torvalds/linux
-cd linux/tools/perf
-make
-make install
+# Install perf
+apt-get install linux-tools-common linux-tools-generic linux-tools-`uname -r`
 
 # [Optional] Allow running perf without sudo
 echo 0 | sudo tee /proc/sys/kernel/kptr_restrict
@@ -502,30 +492,24 @@ cd ../yjit-bench
 PERF=record ruby --yjit-perf=codegen -Iharness-perf benchmarks/lobsters/benchmark.rb
 
 # Aggregate results
-perf script -s ../ruby/misc/yjit_perf.py
+perf script > /tmp/perf.txt
+../ruby/misc/yjit_perf.py /tmp/perf.txt
 ```
 
-#### Using perf without Python support
+#### Building perf with Python support
 
-`misc/yjit_perf.py` also has an extra interface to support `perf` without Python support.
-You need to run `perf script` (instead of `perf script -s`) first, and feed the output to `misc/yjit_perf.py`.
-
-This interface exists primarily for production environments. You can run `perf script` in production,
-export the output locally, and run the script using it.
+`misc/yjit_perf.py` was originally created for `perf script -s`.
+You need to build `perf` from source, but it has a handy interface.
 
 ```bash
-# Install perf
-apt-get install linux-tools-common linux-tools-generic linux-tools-`uname -r`
-
-# [Optional] Allow running perf without sudo
-echo 0 | sudo tee /proc/sys/kernel/kptr_restrict
-echo -1 | sudo tee /proc/sys/kernel/perf_event_paranoid
-
-# Profile Ruby with --yjit-perf=codegen
-cd ../yjit-bench
-PERF=record ruby --yjit-perf=codegen -Iharness-perf benchmarks/lobsters/benchmark.rb
+# Build perf from source for Python support
+sudo apt-get install libpython3-dev python3-pip flex libtraceevent-dev \
+  libelf-dev libunwind-dev libaudit-dev libslang2-dev libdw-dev
+git clone --depth=1 https://github.com/torvalds/linux
+cd linux/tools/perf
+make
+make install
 
 # Aggregate results
-perf script > /tmp/perf.txt
-../ruby/misc/yjit_perf.py /tmp/perf.txt
+perf script -s ../ruby/misc/yjit_perf.py
 ```