v6.10-rc2-scx1

.github/workflows/run-schedulers

@@ -0,0 +1,73 @@
+#!/bin/bash
+#
+# Run sched-ext scheduler for TIMEOUT seconds inside virtme-ng and catch
+# potential errors, then unload the scheduler and return the exit status.
+
+# Maximum time for each scheduler run.
+TEST_TIMEOUT=30
+
+# Maximum timeout for the guest used for each scheduler run (this is used to
+# hard-shutdown the guest in case of system hangs).
+GUEST_TIMEOUT=60
+
+# Check if virtme-ng is available.
+if [ ! -x `which vng` ]; then
+    echo "vng not found, please install virtme-ng to enable testing"
+    exit 1
+fi
+
+function runtest() {
+    local bin="${1}"
+
+    if [ -z "${bin}" ]; then
+        echo "No binary passed to runtest"
+        exit 1
+    fi
+
+    if ! [ -f "${bin}" ]; then
+        echo "Binary ${bin} was not a regular file"
+        exit 1
+    fi
+
+    rm -f /tmp/output
+    (timeout --foreground --preserve-status ${GUEST_TIMEOUT} \
+        vng --force-9p --verbose -- \
+            "timeout --foreground --preserve-status ${TEST_TIMEOUT} ${bin}" \
+                2>&1 </dev/null || true) | tee /tmp/output
+}
+
+# Test all the available schedulers.
+#
+# NOTE: virtme-ng automatically runs the kernel from the current working
+# directory by default.
+#
+# Each scheduler will be tested in a separate instance booted from scratch, to
+# ensure that each run does not impact the others.
+#
+for sched in $(find tools/sched_ext/build/bin -type f -executable); do
+    runtest "${sched}"
+    grep -v " Speculative Return Stack Overflow" /tmp/output | \
+        sed -n -e '/\bBUG:/q1' \
+            -e '/\bWARNING:/q1' \
+            -e '/\berror\b/Iq1' \
+            -e '/\bstall/Iq1' \
+            -e '/\btimeout\b/Iq1'
+    res=$?
+    if [ ${res} -ne 0 ]; then
+        echo "FAIL: ${sched}"
+        exit 1
+    else
+        echo "OK: ${sched}"
+    fi
+done
+
+# Run the selftests suite
+runtest "tools/testing/selftests/sched_ext/runner"
+sed -n -e '/not ok/q1' /tmp/output
+res=$?
+if [ ${res} -ne 0 ]; then
+	echo "FAIL: selftests"
+	echo "output: $(cat /tmp/output)"
+else
+	echo "OK: selftests"
+fi

.github/workflows/sched-ext.config

@@ -0,0 +1,34 @@
+# sched-ext mandatory options
+#
+CONFIG_BPF=y
+CONFIG_BPF_SYSCALL=y
+CONFIG_BPF_JIT=y
+CONFIG_DEBUG_INFO_BTF=y
+CONFIG_BPF_JIT_ALWAYS_ON=y
+CONFIG_BPF_JIT_DEFAULT_ON=y
+CONFIG_SCHED_CLASS_EXT=y
+
+# Enable scheduling debugging
+#
+CONFIG_SCHED_DEBUG=y
+
+# Enable extra scheduling features (for a better code coverage while testing
+# the schedulers)
+#
+CONFIG_SCHED_AUTOGROUP=y
+CONFIG_SCHED_CORE=y
+
+# Enable fully preemptible kernel for a better test coverage of the schedulers
+#
+# CONFIG_PREEMPT_NONE is not set
+# CONFIG_PREEMPT_VOLUNTARY is not set
+CONFIG_PREEMPT=y
+CONFIG_PREEMPT_COUNT=y
+CONFIG_PREEMPTION=y
+CONFIG_PREEMPT_DYNAMIC=y
+CONFIG_PREEMPT_RCU=y
+
+# Additional debugging information (useful to catch potential locking issues)
+#
+CONFIG_DEBUG_LOCKDEP=y
+CONFIG_DEBUG_ATOMIC_SLEEP=y

.github/workflows/test-kernel.yml

@@ -0,0 +1,56 @@
+name: test-kernel
+run-name: ${{ github.actor }} PR run
+on: [pull_request]
+jobs:
+  test-schedulers:
+    runs-on: ubuntu-22.04
+    steps:
+      ### OTHER REPOS ####
+
+      # Hard turn-off interactive mode
+      - run: echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
+
+      # Refresh packages list
+      - run: sudo apt update
+
+      ### DOWNLOAD AND INSTALL DEPENDENCIES ###
+
+      # Download dependencies packaged by Ubuntu
+      - run: sudo apt -y install bc gcc make git coreutils cmake elfutils libelf-dev libunwind-dev libzstd-dev linux-headers-generic linux-tools-common linux-tools-generic ninja-build python3-pip python3-requests qemu-kvm udev iproute2 busybox-static libvirt-clients kbd kmod file rsync zstd pahole flex bison cpio libcap-dev libelf-dev python3-dev cargo rustc gcc-multilib
+
+      # clang 17
+      # Use a custom llvm.sh script which includes the -y flag for
+      # add-apt-repository. Otherwise, the CI job will hang. If and when
+      # https://github.com/opencollab/llvm-jenkins.debian.net/pull/26 is
+      # merged, we can go back to using https://apt.llvm.org/llvm.sh.
+      - run: wget https://raw.githubusercontent.com/Byte-Lab/llvm-jenkins.debian.net/fix_llvmsh/llvm.sh
+      - run: chmod +x llvm.sh
+      - run: sudo ./llvm.sh all
+      - run: sudo ln -sf /usr/bin/clang-17 /usr/bin/clang
+      - run: sudo ln -sf /usr/bin/llvm-strip-17 /usr/bin/llvm-strip
+
+      # Checkout repository
+      - uses: actions/checkout@v4
+
+      # Install virtme-ng
+      - run: pip install virtme-ng
+
+      ### END DEPENDENCIES ###
+
+      # Build a minimal kernel (with sched-ext enabled) using virtme-ng
+      - run: vng -v --build --config .github/workflows/sched-ext.config
+
+      # Build the selftests suite
+      - run: make -j $(nproc) -C tools/testing/selftests/sched_ext
+
+      # Build the in-kernel schedulers
+      - run: make -j $(nproc) -C tools/sched_ext
+
+      # Setup KVM support
+      - run: |
+          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
+          sudo udevadm control --reload-rules
+          sudo udevadm trigger --name-match=kvm
+
+      # Test the schedulers inside the recompile kernel
+      - run: .github/workflows/run-schedulers

.gitignore

@@ -171,3 +171,6 @@ sphinx_*/
 
 # Rust analyzer configuration
 /rust-project.json
+
+# Include ".github" directory
+!.github/

Documentation/bpf/libbpf/libbpf_overview.rst

@@ -219,6 +219,14 @@ compilation and skeleton generation. Using Libbpf-rs will make building user
 space part of the BPF application easier. Note that the BPF program themselves
 must still be written in plain C.
 
+libbpf logging
+==============
+
+By default, libbpf logs informational and warning messages to stderr. The
+verbosity of these messages can be controlled by setting the environment
+variable LIBBPF_LOG_LEVEL to either warn, info, or debug. A custom log
+callback can be set using ``libbpf_set_print()``.
+
 Additional Documentation
 ========================
 

Documentation/bpf/standardization/abi.rst

@@ -23,3 +23,6 @@ The BPF calling convention is defined as:
 
 R0 - R5 are scratch registers and BPF programs needs to spill/fill them if
 necessary across calls.
+
+The BPF program needs to store the return value into register R0 before doing an
+``EXIT``.