new(ci): added a perf CI job.

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>

.github/workflows/ci.yml

@@ -341,3 +341,75 @@ jobs:
           cd build && emcmake cmake -DUSE_BUNDLED_DEPS=True ../
           emmake make -j4
           emmake make run-unit-tests -j4
+
+  perf-libs-linux-amd64:
+    runs-on: 'ubuntu-22.04'
+    steps:
+      - name: Checkout Libs ⤵️
+        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        with:
+          fetch-depth: 0
+
+      - name: Install deps ⛓️
+        run: |
+          sudo apt update && sudo apt install -y --no-install-recommends ca-certificates cmake build-essential git clang llvm pkg-config autoconf automake libtool libelf-dev wget libc-ares-dev libcurl4-openssl-dev libssl-dev libtbb-dev libjq-dev libjsoncpp-dev libgrpc++-dev protobuf-compiler-grpc libgtest-dev libprotobuf-dev
+          sudo .github/install-deps.sh
+
+      - name: Build
+        run: |
+          mkdir -p build
+          cd build && cmake -DUSE_BUNDLED_DEPS=False ../
+          make unit-test-libsinsp -j4
+
+      - name: Run Perf
+        run: |
+          cd build
+          sudo perf record --call-graph dwarf ./libsinsp/test/unit-test-libsinsp
+
+      - name: Archive perf report (PR)
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32 # v3.1.3
+        with:
+          name: perf_report
+          retention-days: 1 # just 1 day because they are big and there can be multiple ones (ie: on each push to the PR)
+          path: build/perf.data
+          if-no-files-found: error
+
+      - name: Archive perf report (master)
+        if: github.event_name == 'push'
+        uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32 # v3.1.3
+        with:
+          name: perf_report
+          retention-days: 14 # 14 days because this is the artifact on master; we need to retain it to be able to properly diff it
+          path: build/perf.data
+          if-no-files-found: error
+
+      - name: Download latest master report
+        if: github.event_name == 'pull_request'
+        uses: dawidd6/action-download-artifact@v6
+        with:
+          workflow: ci.yml
+          branch: master
+          event: push
+          name: perf_report
+
+      - name: Diff from master
+        if: github.event_name == 'pull_request'
+        run: |
+          sudo perf diff perf.data build/perf.data -d unit-test-libsinsp -b -o 0 --percentage relative -q &> perf_diff.txt
+
+      - name: Archive perf diff
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32 # v3.1.3
+        with:
+          name: perf_diff
+          path: perf_diff.txt
+          if-no-files-found: error
+
+      - name: Check > 2% threshold
+        if: github.event_name == 'pull_request'
+        run: |
+          awk '{if (substr($2,RSTART+RLENGTH)+0 > 2) print }' perf_diff.txt &> perf_diff_above_thresh.txt
+          if [ "$(wc -l perf_diff_above_thresh.txt | awk '{print $1}')" -ne "0" ]; then
+            exit 1
+          fi