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-rw-r--r--Makefile8
-rw-r--r--tools/Makefile10
-rw-r--r--tools/sched_ext/.gitignore2
-rw-r--r--tools/sched_ext/Makefile246
-rw-r--r--tools/sched_ext/include/bpf-compat/gnu/stubs.h11
-rw-r--r--tools/sched_ext/include/scx/common.bpf.h379
-rw-r--r--tools/sched_ext/include/scx/common.h75
-rw-r--r--tools/sched_ext/include/scx/compat.bpf.h28
-rw-r--r--tools/sched_ext/include/scx/compat.h153
-rw-r--r--tools/sched_ext/include/scx/user_exit_info.h64
-rw-r--r--tools/sched_ext/scx_qmap.bpf.c264
-rw-r--r--tools/sched_ext/scx_qmap.c99
-rw-r--r--tools/sched_ext/scx_simple.bpf.c63
-rw-r--r--tools/sched_ext/scx_simple.c99
14 files changed, 1499 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index 7f921ae547f1..b2e57dfe8c7a 100644
--- a/Makefile
+++ b/Makefile
@@ -1355,6 +1355,12 @@ ifneq ($(wildcard $(resolve_btfids_O)),)
$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
endif
+tools-clean-targets := sched_ext
+PHONY += $(tools-clean-targets)
+$(tools-clean-targets):
+ $(Q)$(MAKE) -sC tools $@_clean
+tools_clean: $(tools-clean-targets)
+
# Clear a bunch of variables before executing the submake
ifeq ($(quiet),silent_)
tools_silent=s
@@ -1527,7 +1533,7 @@ PHONY += $(mrproper-dirs) mrproper
$(mrproper-dirs):
$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
-mrproper: clean $(mrproper-dirs)
+mrproper: clean $(mrproper-dirs) tools_clean
$(call cmd,rmfiles)
@find . $(RCS_FIND_IGNORE) \
\( -name '*.rmeta' \) \
diff --git a/tools/Makefile b/tools/Makefile
index 276f5d0d53a4..278d24723b74 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -28,6 +28,7 @@ help:
@echo ' pci - PCI tools'
@echo ' perf - Linux performance measurement and analysis tool'
@echo ' selftests - various kernel selftests'
+ @echo ' sched_ext - sched_ext example schedulers'
@echo ' bootconfig - boot config tool'
@echo ' spi - spi tools'
@echo ' tmon - thermal monitoring and tuning tool'
@@ -91,6 +92,9 @@ perf: FORCE
$(Q)mkdir -p $(PERF_O) .
$(Q)$(MAKE) --no-print-directory -C perf O=$(PERF_O) subdir=
+sched_ext: FORCE
+ $(call descend,sched_ext)
+
selftests: FORCE
$(call descend,testing/$@)
@@ -184,6 +188,9 @@ perf_clean:
$(Q)mkdir -p $(PERF_O) .
$(Q)$(MAKE) --no-print-directory -C perf O=$(PERF_O) subdir= clean
+sched_ext_clean:
+ $(call descend,sched_ext,clean)
+
selftests_clean:
$(call descend,testing/$(@:_clean=),clean)
@@ -213,6 +220,7 @@ clean: acpi_clean counter_clean cpupower_clean hv_clean firewire_clean \
mm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
freefall_clean build_clean libbpf_clean libsubcmd_clean \
gpio_clean objtool_clean leds_clean wmi_clean pci_clean firmware_clean debugging_clean \
- intel-speed-select_clean tracing_clean thermal_clean thermometer_clean thermal-engine_clean
+ intel-speed-select_clean tracing_clean thermal_clean thermometer_clean thermal-engine_clean \
+ sched_ext_clean
.PHONY: FORCE
diff --git a/tools/sched_ext/.gitignore b/tools/sched_ext/.gitignore
new file mode 100644
index 000000000000..d6264fe1c8cd
--- /dev/null
+++ b/tools/sched_ext/.gitignore
@@ -0,0 +1,2 @@
+tools/
+build/
diff --git a/tools/sched_ext/Makefile b/tools/sched_ext/Makefile
new file mode 100644
index 000000000000..626782a21375
--- /dev/null
+++ b/tools/sched_ext/Makefile
@@ -0,0 +1,246 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+include ../build/Build.include
+include ../scripts/Makefile.arch
+include ../scripts/Makefile.include
+
+all: all_targets
+
+ifneq ($(LLVM),)
+ifneq ($(filter %/,$(LLVM)),)
+LLVM_PREFIX := $(LLVM)
+else ifneq ($(filter -%,$(LLVM)),)
+LLVM_SUFFIX := $(LLVM)
+endif
+
+CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi
+CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu
+CLANG_TARGET_FLAGS_hexagon := hexagon-linux-musl
+CLANG_TARGET_FLAGS_m68k := m68k-linux-gnu
+CLANG_TARGET_FLAGS_mips := mipsel-linux-gnu
+CLANG_TARGET_FLAGS_powerpc := powerpc64le-linux-gnu
+CLANG_TARGET_FLAGS_riscv := riscv64-linux-gnu
+CLANG_TARGET_FLAGS_s390 := s390x-linux-gnu
+CLANG_TARGET_FLAGS_x86 := x86_64-linux-gnu
+CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(ARCH))
+
+ifeq ($(CROSS_COMPILE),)
+ifeq ($(CLANG_TARGET_FLAGS),)
+$(error Specify CROSS_COMPILE or add '--target=' option to lib.mk)
+else
+CLANG_FLAGS += --target=$(CLANG_TARGET_FLAGS)
+endif # CLANG_TARGET_FLAGS
+else
+CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
+endif # CROSS_COMPILE
+
+CC := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) $(CLANG_FLAGS) -fintegrated-as
+else
+CC := $(CROSS_COMPILE)gcc
+endif # LLVM
+
+CURDIR := $(abspath .)
+TOOLSDIR := $(abspath ..)
+LIBDIR := $(TOOLSDIR)/lib
+BPFDIR := $(LIBDIR)/bpf
+TOOLSINCDIR := $(TOOLSDIR)/include
+BPFTOOLDIR := $(TOOLSDIR)/bpf/bpftool
+APIDIR := $(TOOLSINCDIR)/uapi
+GENDIR := $(abspath ../../include/generated)
+GENHDR := $(GENDIR)/autoconf.h
+
+ifeq ($(O),)
+OUTPUT_DIR := $(CURDIR)/build
+else
+OUTPUT_DIR := $(O)/build
+endif # O
+OBJ_DIR := $(OUTPUT_DIR)/obj
+INCLUDE_DIR := $(OUTPUT_DIR)/include
+BPFOBJ_DIR := $(OBJ_DIR)/libbpf
+SCXOBJ_DIR := $(OBJ_DIR)/sched_ext
+BINDIR := $(OUTPUT_DIR)/bin
+BPFOBJ := $(BPFOBJ_DIR)/libbpf.a
+ifneq ($(CROSS_COMPILE),)
+HOST_BUILD_DIR := $(OBJ_DIR)/host
+HOST_OUTPUT_DIR := host-tools
+HOST_INCLUDE_DIR := $(HOST_OUTPUT_DIR)/include
+else
+HOST_BUILD_DIR := $(OBJ_DIR)
+HOST_OUTPUT_DIR := $(OUTPUT_DIR)
+HOST_INCLUDE_DIR := $(INCLUDE_DIR)
+endif
+HOST_BPFOBJ := $(HOST_BUILD_DIR)/libbpf/libbpf.a
+RESOLVE_BTFIDS := $(HOST_BUILD_DIR)/resolve_btfids/resolve_btfids
+DEFAULT_BPFTOOL := $(HOST_OUTPUT_DIR)/sbin/bpftool
+
+VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
+ $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
+ ../../vmlinux \
+ /sys/kernel/btf/vmlinux \
+ /boot/vmlinux-$(shell uname -r)
+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
+ifeq ($(VMLINUX_BTF),)
+$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
+endif
+
+BPFTOOL ?= $(DEFAULT_BPFTOOL)
+
+ifneq ($(wildcard $(GENHDR)),)
+ GENFLAGS := -DHAVE_GENHDR
+endif
+
+CFLAGS += -g -O2 -rdynamic -pthread -Wall -Werror $(GENFLAGS) \
+ -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \
+ -I$(TOOLSINCDIR) -I$(APIDIR) -I$(CURDIR)/include
+
+# Silence some warnings when compiled with clang
+ifneq ($(LLVM),)
+CFLAGS += -Wno-unused-command-line-argument
+endif
+
+LDFLAGS = -lelf -lz -lpthread
+
+IS_LITTLE_ENDIAN = $(shell $(CC) -dM -E - </dev/null | \
+ grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
+
+# Get Clang's default includes on this system, as opposed to those seen by
+# '-target bpf'. This fixes "missing" files on some architectures/distros,
+# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
+#
+# Use '-idirafter': Don't interfere with include mechanics except where the
+# build would have failed anyways.
+define get_sys_includes
+$(shell $(1) -v -E - </dev/null 2>&1 \
+ | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
+$(shell $(1) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
+endef
+
+BPF_CFLAGS = -g -D__TARGET_ARCH_$(SRCARCH) \
+ $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian) \
+ -I$(CURDIR)/include -I$(CURDIR)/include/bpf-compat \
+ -I$(INCLUDE_DIR) -I$(APIDIR) \
+ -I../../include \
+ $(call get_sys_includes,$(CLANG)) \
+ -Wall -Wno-compare-distinct-pointer-types \
+ -O2 -mcpu=v3
+
+# sort removes libbpf duplicates when not cross-building
+MAKE_DIRS := $(sort $(OBJ_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \
+ $(HOST_BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/resolve_btfids \
+ $(INCLUDE_DIR) $(SCXOBJ_DIR) $(BINDIR))
+
+$(MAKE_DIRS):
+ $(call msg,MKDIR,,$@)
+ $(Q)mkdir -p $@
+
+$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \
+ $(APIDIR)/linux/bpf.h \
+ | $(OBJ_DIR)/libbpf
+ $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(OBJ_DIR)/libbpf/ \
+ EXTRA_CFLAGS='-g -O0 -fPIC' \
+ DESTDIR=$(OUTPUT_DIR) prefix= all install_headers
+
+$(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \
+ $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/bpftool
+ $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \
+ ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) \
+ EXTRA_CFLAGS='-g -O0' \
+ OUTPUT=$(HOST_BUILD_DIR)/bpftool/ \
+ LIBBPF_OUTPUT=$(HOST_BUILD_DIR)/libbpf/ \
+ LIBBPF_DESTDIR=$(HOST_OUTPUT_DIR)/ \
+ prefix= DESTDIR=$(HOST_OUTPUT_DIR)/ install-bin
+
+$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) | $(INCLUDE_DIR)
+ifeq ($(VMLINUX_H),)
+ $(call msg,GEN,,$@)
+ $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
+else
+ $(call msg,CP,,$@)
+ $(Q)cp "$(VMLINUX_H)" $@
+endif
+
+$(SCXOBJ_DIR)/%.bpf.o: %.bpf.c $(INCLUDE_DIR)/vmlinux.h include/scx/*.h \
+ | $(BPFOBJ) $(SCXOBJ_DIR)
+ $(call msg,CLNG-BPF,,$(notdir $@))
+ $(Q)$(CLANG) $(BPF_CFLAGS) -target bpf -c $< -o $@
+
+$(INCLUDE_DIR)/%.bpf.skel.h: $(SCXOBJ_DIR)/%.bpf.o $(INCLUDE_DIR)/vmlinux.h $(BPFTOOL)
+ $(eval sched=$(notdir $@))
+ $(call msg,GEN-SKEL,,$(sched))
+ $(Q)$(BPFTOOL) gen object $(<:.o=.linked1.o) $<
+ $(Q)$(BPFTOOL) gen object $(<:.o=.linked2.o) $(<:.o=.linked1.o)
+ $(Q)$(BPFTOOL) gen object $(<:.o=.linked3.o) $(<:.o=.linked2.o)
+ $(Q)diff $(<:.o=.linked2.o) $(<:.o=.linked3.o)
+ $(Q)$(BPFTOOL) gen skeleton $(<:.o=.linked3.o) name $(subst .bpf.skel.h,,$(sched)) > $@
+ $(Q)$(BPFTOOL) gen subskeleton $(<:.o=.linked3.o) name $(subst .bpf.skel.h,,$(sched)) > $(@:.skel.h=.subskel.h)
+
+SCX_COMMON_DEPS := include/scx/common.h include/scx/user_exit_info.h | $(BINDIR)
+
+c-sched-targets = scx_simple scx_qmap
+
+$(addprefix $(BINDIR)/,$(c-sched-targets)): \
+ $(BINDIR)/%: \
+ $(filter-out %.bpf.c,%.c) \
+ $(INCLUDE_DIR)/%.bpf.skel.h \
+ $(SCX_COMMON_DEPS)
+ $(eval sched=$(notdir $@))
+ $(CC) $(CFLAGS) -c $(sched).c -o $(SCXOBJ_DIR)/$(sched).o
+ $(CC) -o $@ $(SCXOBJ_DIR)/$(sched).o $(HOST_BPFOBJ) $(LDFLAGS)
+
+$(c-sched-targets): %: $(BINDIR)/%
+
+install: all
+ $(Q)mkdir -p $(DESTDIR)/usr/local/bin/
+ $(Q)cp $(BINDIR)/* $(DESTDIR)/usr/local/bin/
+
+clean:
+ rm -rf $(OUTPUT_DIR) $(HOST_OUTPUT_DIR)
+ rm -f *.o *.bpf.o *.bpf.skel.h *.bpf.subskel.h
+ rm -f $(c-sched-targets)
+
+help:
+ @echo 'Building targets'
+ @echo '================'
+ @echo ''
+ @echo ' all - Compile all schedulers'
+ @echo ''
+ @echo 'Alternatively, you may compile individual schedulers:'
+ @echo ''
+ @printf ' %s\n' $(c-sched-targets)
+ @echo ''
+ @echo 'For any scheduler build target, you may specify an alternative'
+ @echo 'build output path with the O= environment variable. For example:'
+ @echo ''
+ @echo ' O=/tmp/sched_ext make all'
+ @echo ''
+ @echo 'will compile all schedulers, and emit the build artifacts to'
+ @echo '/tmp/sched_ext/build.'
+ @echo ''
+ @echo ''
+ @echo 'Installing targets'
+ @echo '=================='
+ @echo ''
+ @echo ' install - Compile and install all schedulers to /usr/bin.'
+ @echo ' You may specify the DESTDIR= environment variable'
+ @echo ' to indicate a prefix for /usr/bin. For example:'
+ @echo ''
+ @echo ' DESTDIR=/tmp/sched_ext make install'
+ @echo ''
+ @echo ' will build the schedulers in CWD/build, and'
+ @echo ' install the schedulers to /tmp/sched_ext/usr/bin.'
+ @echo ''
+ @echo ''
+ @echo 'Cleaning targets'
+ @echo '================'
+ @echo ''
+ @echo ' clean - Remove all generated files'
+
+all_targets: $(c-sched-targets)
+
+.PHONY: all all_targets $(c-sched-targets) clean help
+
+# delete failed targets
+.DELETE_ON_ERROR:
+
+# keep intermediate (.bpf.skel.h, .bpf.o, etc) targets
+.SECONDARY:
diff --git a/tools/sched_ext/include/bpf-compat/gnu/stubs.h b/tools/sched_ext/include/bpf-compat/gnu/stubs.h
new file mode 100644
index 000000000000..ad7d139ce907
--- /dev/null
+++ b/tools/sched_ext/include/bpf-compat/gnu/stubs.h
@@ -0,0 +1,11 @@
+/*
+ * Dummy gnu/stubs.h. clang can end up including /usr/include/gnu/stubs.h when
+ * compiling BPF files although its content doesn't play any role. The file in
+ * turn includes stubs-64.h or stubs-32.h depending on whether __x86_64__ is
+ * defined. When compiling a BPF source, __x86_64__ isn't set and thus
+ * stubs-32.h is selected. However, the file is not there if the system doesn't
+ * have 32bit glibc devel package installed leading to a build failure.
+ *
+ * The problem is worked around by making this file available in the include
+ * search paths before the system one when building BPF.
+ */
diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h
new file mode 100644
index 000000000000..833fe1bdccf9
--- /dev/null
+++ b/tools/sched_ext/include/scx/common.bpf.h
@@ -0,0 +1,379 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2022 David Vernet <dvernet@meta.com>
+ */
+#ifndef __SCX_COMMON_BPF_H
+#define __SCX_COMMON_BPF_H
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <asm-generic/errno.h>
+#include "user_exit_info.h"
+
+#define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
+#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
+#define PF_EXITING 0x00000004
+#define CLOCK_MONOTONIC 1
+
+/*
+ * Earlier versions of clang/pahole lost upper 32bits in 64bit enums which can
+ * lead to really confusing misbehaviors. Let's trigger a build failure.
+ */
+static inline void ___vmlinux_h_sanity_check___(void)
+{
+ _Static_assert(SCX_DSQ_FLAG_BUILTIN,
+ "bpftool generated vmlinux.h is missing high bits for 64bit enums, upgrade clang and pahole");
+}
+
+s32 scx_bpf_create_dsq(u64 dsq_id, s32 node) __ksym;
+s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool *is_idle) __ksym;
+void scx_bpf_dispatch(struct task_struct *p, u64 dsq_id, u64 slice, u64 enq_flags) __ksym;
+u32 scx_bpf_dispatch_nr_slots(void) __ksym;
+void scx_bpf_dispatch_cancel(void) __ksym;
+bool scx_bpf_consume(u64 dsq_id) __ksym;
+s32 scx_bpf_dsq_nr_queued(u64 dsq_id) __ksym;
+void scx_bpf_destroy_dsq(u64 dsq_id) __ksym;
+void scx_bpf_exit_bstr(s64 exit_code, char *fmt, unsigned long long *data, u32 data__sz) __ksym __weak;
+void scx_bpf_error_bstr(char *fmt, unsigned long long *data, u32 data_len) __ksym;
+u32 scx_bpf_nr_cpu_ids(void) __ksym __weak;
+const struct cpumask *scx_bpf_get_possible_cpumask(void) __ksym __weak;
+const struct cpumask *scx_bpf_get_online_cpumask(void) __ksym __weak;
+void scx_bpf_put_cpumask(const struct cpumask *cpumask) __ksym __weak;
+const struct cpumask *scx_bpf_get_idle_cpumask(void) __ksym;
+const struct cpumask *scx_bpf_get_idle_smtmask(void) __ksym;
+void scx_bpf_put_idle_cpumask(const struct cpumask *cpumask) __ksym;
+bool scx_bpf_test_and_clear_cpu_idle(s32 cpu) __ksym;
+s32 scx_bpf_pick_idle_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;
+s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;
+bool scx_bpf_task_running(const struct task_struct *p) __ksym;
+s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym;
+
+static inline __attribute__((format(printf, 1, 2)))
+void ___scx_bpf_bstr_format_checker(const char *fmt, ...) {}
+
+/*
+ * Helper macro for initializing the fmt and variadic argument inputs to both
+ * bstr exit kfuncs. Callers to this function should use ___fmt and ___param to
+ * refer to the initialized list of inputs to the bstr kfunc.
+ */
+#define scx_bpf_bstr_preamble(fmt, args...) \
+ static char ___fmt[] = fmt; \
+ /* \
+ * Note that __param[] must have at least one \
+ * element to keep the verifier happy. \
+ */ \
+ unsigned long long ___param[___bpf_narg(args) ?: 1] = {}; \
+ \
+ _Pragma("GCC diagnostic push") \
+ _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
+ ___bpf_fill(___param, args); \
+ _Pragma("GCC diagnostic pop") \
+
+/*
+ * scx_bpf_exit() wraps the scx_bpf_exit_bstr() kfunc with variadic arguments
+ * instead of an array of u64. Using this macro will cause the scheduler to
+ * exit cleanly with the specified exit code being passed to user space.
+ */
+#define scx_bpf_exit(code, fmt, args...) \
+({ \
+ scx_bpf_bstr_preamble(fmt, args) \
+ scx_bpf_exit_bstr(code, ___fmt, ___param, sizeof(___param)); \
+ ___scx_bpf_bstr_format_checker(fmt, ##args); \
+})
+
+/*
+ * scx_bpf_error() wraps the scx_bpf_error_bstr() kfunc with variadic arguments
+ * instead of an array of u64. Invoking this macro will cause the scheduler to
+ * exit in an erroneous state, with diagnostic information being passed to the
+ * user.
+ */
+#define scx_bpf_error(fmt, args...) \
+({ \
+ scx_bpf_bstr_preamble(fmt, args) \
+ scx_bpf_error_bstr(___fmt, ___param, sizeof(___param)); \
+ ___scx_bpf_bstr_format_checker(fmt, ##args); \
+})
+
+#define BPF_STRUCT_OPS(name, args...) \
+SEC("struct_ops/"#name) \
+BPF_PROG(name, ##args)
+
+#define BPF_STRUCT_OPS_SLEEPABLE(name, args...) \
+SEC("struct_ops.s/"#name) \
+BPF_PROG(name, ##args)
+
+/**
+ * RESIZABLE_ARRAY - Generates annotations for an array that may be resized
+ * @elfsec: the data section of the BPF program in which to place the array
+ * @arr: the name of the array
+ *
+ * libbpf has an API for setting map value sizes. Since data sections (i.e.
+ * bss, data, rodata) themselves are maps, a data section can be resized. If
+ * a data section has an array as its last element, the BTF info for that
+ * array will be adjusted so that length of the array is extended to meet the
+ * new length of the data section. This macro annotates an array to have an
+ * element count of one with the assumption that this array can be resized
+ * within the userspace program. It also annotates the section specifier so
+ * this array exists in a custom sub data section which can be resized
+ * independently.
+ *
+ * See RESIZE_ARRAY() for the userspace convenience macro for resizing an
+ * array declared with RESIZABLE_ARRAY().
+ */
+#define RESIZABLE_ARRAY(elfsec, arr) arr[1] SEC("."#elfsec"."#arr)
+
+/**
+ * MEMBER_VPTR - Obtain the verified pointer to a struct or array member
+ * @base: struct or array to index
+ * @member: dereferenced member (e.g. .field, [idx0][idx1], .field[idx0] ...)
+ *
+ * The verifier often gets confused by the instruction sequence the compiler
+ * generates for indexing struct fields or arrays. This macro forces the
+ * compiler to generate a code sequence which first calculates the byte offset,
+ * checks it against the struct or array size and add that byte offset to
+ * generate the pointer to the member to help the verifier.
+ *
+ * Ideally, we want to abort if the calculated offset is out-of-bounds. However,
+ * BPF currently doesn't support abort, so evaluate to %NULL instead. The caller
+ * must check for %NULL and take appropriate action to appease the verifier. To
+ * avoid confusing the verifier, it's best to check for %NULL and dereference
+ * immediately.
+ *
+ * vptr = MEMBER_VPTR(my_array, [i][j]);
+ * if (!vptr)
+ * return error;
+ * *vptr = new_value;
+ *
+ * sizeof(@base) should encompass the memory area to be accessed and thus can't
+ * be a pointer to the area. Use `MEMBER_VPTR(*ptr, .member)` instead of
+ * `MEMBER_VPTR(ptr, ->member)`.
+ */
+#define MEMBER_VPTR(base, member) (typeof((base) member) *) \
+({ \
+ u64 __base = (u64)&(base); \
+ u64 __addr = (u64)&((base) member) - __base; \
+ _Static_assert(sizeof(base) >= sizeof((base) member), \
+ "@base is smaller than @member, is @base a pointer?"); \
+ asm volatile ( \
+ "if %0 <= %[max] goto +2\n" \
+ "%0 = 0\n" \
+ "goto +1\n" \
+ "%0 += %1\n" \
+ : "+r"(__addr) \
+ : "r"(__base), \
+ [max]"i"(sizeof(base) - sizeof((base) member))); \
+ __addr; \
+})
+
+/**
+ * ARRAY_ELEM_PTR - Obtain the verified pointer to an array element
+ * @arr: array to index into
+ * @i: array index
+ * @n: number of elements in array
+ *
+ * Similar to MEMBER_VPTR() but is intended for use with arrays where the
+ * element count needs to be explicit.
+ * It can be used in cases where a global array is defined with an initial
+ * size but is intended to be be resized before loading the BPF program.
+ * Without this version of the macro, MEMBER_VPTR() will use the compile time
+ * size of the array to compute the max, which will result in rejection by
+ * the verifier.
+ */
+#define ARRAY_ELEM_PTR(arr, i, n) (typeof(arr[i]) *) \
+({ \
+ u64 __base = (u64)arr; \
+ u64 __addr = (u64)&(arr[i]) - __base; \
+ asm volatile ( \
+ "if %0 <= %[max] goto +2\n" \
+ "%0 = 0\n" \
+ "goto +1\n" \
+ "%0 += %1\n" \
+ : "+r"(__addr) \
+ : "r"(__base), \
+ [max]"r"(sizeof(arr[0]) * ((n) - 1))); \
+ __addr; \
+})
+
+
+/*
+ * BPF declarations and helpers
+ */
+
+/* list and rbtree */
+#define __contains(name, node) __attribute__((btf_decl_tag("contains:" #name ":" #node)))
+#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
+
+void *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym;
+void bpf_obj_drop_impl(void *kptr, void *meta) __ksym;
+
+#define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL))
+#define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL)
+
+void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node) __ksym;
+void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node) __ksym;
+struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head) __ksym;
+struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) __ksym;
+struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root,
+ struct bpf_rb_node *node) __ksym;
+int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node,
+ bool (less)(struct bpf_rb_node *a, const struct bpf_rb_node *b),
+ void *meta, __u64 off) __ksym;
+#define bpf_rbtree_add(head, node, less) bpf_rbtree_add_impl(head, node, less, NULL, 0)
+
+struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root) __ksym;
+
+void *bpf_refcount_acquire_impl(void *kptr, void *meta) __ksym;
+#define bpf_refcount_acquire(kptr) bpf_refcount_acquire_impl(kptr, NULL)
+
+/* task */
+struct task_struct *bpf_task_from_pid(s32 pid) __ksym;
+struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym;
+void bpf_task_release(struct task_struct *p) __ksym;
+
+/* cgroup */
+struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym;
+void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
+struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym;
+
+/* css iteration */
+struct bpf_iter_css;
+struct cgroup_subsys_state;
+extern int bpf_iter_css_new(struct bpf_iter_css *it,
+ struct cgroup_subsys_state *start,
+ unsigned int flags) __weak __ksym;
+extern struct cgroup_subsys_state *
+bpf_iter_css_next(struct bpf_iter_css *it) __weak __ksym;
+extern void bpf_iter_css_destroy(struct bpf_iter_css *it) __weak __ksym;
+
+/* cpumask */
+struct bpf_cpumask *bpf_cpumask_create(void) __ksym;
+struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym;
+void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
+u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym;
+u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym;
+void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
+void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
+bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym;
+bool bpf_cpumask_test_and_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
+bool bpf_cpumask_test_and_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
+void bpf_cpumask_setall(struct bpf_cpumask *cpumask) __ksym;
+void bpf_cpumask_clear(struct bpf_cpumask *cpumask) __ksym;
+bool bpf_cpumask_and(struct bpf_cpumask *dst, const struct cpumask *src1,
+ const struct cpumask *src2) __ksym;
+void bpf_cpumask_or(struct bpf_cpumask *dst, const struct cpumask *src1,
+ const struct cpumask *src2) __ksym;
+void bpf_cpumask_xor(struct bpf_cpumask *dst, const struct cpumask *src1,
+ const struct cpumask *src2) __ksym;
+bool bpf_cpumask_equal(const struct cpumask *src1, const struct cpumask *src2) __ksym;
+bool bpf_cpumask_intersects(const struct cpumask *src1, const struct cpumask *src2) __ksym;
+bool bpf_cpumask_subset(const struct cpumask *src1, const struct cpumask *src2) __ksym;
+bool bpf_cpumask_empty(const struct cpumask *cpumask) __ksym;
+bool bpf_cpumask_full(const struct cpumask *cpumask) __ksym;
+void bpf_cpumask_copy(struct bpf_cpumask *dst, const struct cpumask *src) __ksym;
+u32 bpf_cpumask_any_distribute(const struct cpumask *cpumask) __ksym;
+u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
+ const struct cpumask *src2) __ksym;
+
+/* rcu */
+void bpf_rcu_read_lock(void) __ksym;
+void bpf_rcu_read_unlock(void) __ksym;
+
+
+/*
+ * Other helpers
+ */
+
+/* useful compiler attributes */
+#define likely(x) __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+#define __maybe_unused __attribute__((__unused__))
+
+/*
+ * READ/WRITE_ONCE() are from kernel (include/asm-generic/rwonce.h). They
+ * prevent compiler from caching, redoing or reordering reads or writes.
+ */
+typedef __u8 __attribute__((__may_alias__)) __u8_alias_t;
+typedef __u16 __attribute__((__may_alias__)) __u16_alias_t;
+typedef __u32 __attribute__((__may_alias__)) __u32_alias_t;
+typedef __u64 __attribute__((__may_alias__)) __u64_alias_t;
+
+static __always_inline void __read_once_size(const volatile void *p, void *res, int size)
+{
+ switch (size) {
+ case 1: *(__u8_alias_t *) res = *(volatile __u8_alias_t *) p; break;
+ case 2: *(__u16_alias_t *) res = *(volatile __u16_alias_t *) p; break;
+ case 4: *(__u32_alias_t *) res = *(volatile __u32_alias_t *) p; break;
+ case 8: *(__u64_alias_t *) res = *(volatile __u64_alias_t *) p; break;
+ default:
+ barrier();
+ __builtin_memcpy((void *)res, (const void *)p, size);
+ barrier();
+ }
+}
+
+static __always_inline void __write_once_size(volatile void *p, void *res, int size)
+{
+ switch (size) {
+ case 1: *(volatile __u8_alias_t *) p = *(__u8_alias_t *) res; break;
+ case 2: *(volatile __u16_alias_t *) p = *(__u16_alias_t *) res; break;
+ case 4: *(volatile __u32_alias_t *) p = *(__u32_alias_t *) res; break;
+ case 8: *(volatile __u64_alias_t *) p = *(__u64_alias_t *) res; break;
+ default:
+ barrier();
+ __builtin_memcpy((void *)p, (const void *)res, size);
+ barrier();
+ }
+}
+
+#define READ_ONCE(x) \
+({ \
+ union { typeof(x) __val; char __c[1]; } __u = \
+ { .__c = { 0 } }; \
+ __read_once_size(&(x), __u.__c, sizeof(x)); \
+ __u.__val; \
+})
+
+#define WRITE_ONCE(x, val) \
+({ \
+ union { typeof(x) __val; char __c[1]; } __u = \
+ { .__val = (val) }; \
+ __write_once_size(&(x), __u.__c, sizeof(x)); \
+ __u.__val; \
+})
+
+/*
+ * log2_u32 - Compute the base 2 logarithm of a 32-bit exponential value.
+ * @v: The value for which we're computing the base 2 logarithm.
+ */
+static inline u32 log2_u32(u32 v)
+{
+ u32 r;
+ u32 shift;
+
+ r = (v > 0xFFFF) << 4; v >>= r;
+ shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+ shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+ shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+ r |= (v >> 1);
+ return r;
+}
+
+/*
+ * log2_u64 - Compute the base 2 logarithm of a 64-bit exponential value.
+ * @v: The value for which we're computing the base 2 logarithm.
+ */
+static inline u32 log2_u64(u64 v)
+{
+ u32 hi = v >> 32;
+ if (hi)
+ return log2_u32(hi) + 32 + 1;
+ else
+ return log2_u32(v) + 1;
+}
+
+#include "compat.bpf.h"
+
+#endif /* __SCX_COMMON_BPF_H */
diff --git a/tools/sched_ext/include/scx/common.h b/tools/sched_ext/include/scx/common.h
new file mode 100644
index 000000000000..5b0f90152152
--- /dev/null
+++ b/tools/sched_ext/include/scx/common.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2023 David Vernet <dvernet@meta.com>
+ */
+#ifndef __SCHED_EXT_COMMON_H
+#define __SCHED_EXT_COMMON_H
+
+#ifdef __KERNEL__
+#error "Should not be included by BPF programs"
+#endif
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <errno.h>
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
+
+#define SCX_BUG(__fmt, ...) \
+ do { \
+ fprintf(stderr, "[SCX_BUG] %s:%d", __FILE__, __LINE__); \
+ if (errno) \
+ fprintf(stderr, " (%s)\n", strerror(errno)); \
+ else \
+ fprintf(stderr, "\n"); \
+ fprintf(stderr, __fmt __VA_OPT__(,) __VA_ARGS__); \
+ fprintf(stderr, "\n"); \
+ \
+ exit(EXIT_FAILURE); \
+ } while (0)
+
+#define SCX_BUG_ON(__cond, __fmt, ...) \
+ do { \
+ if (__cond) \
+ SCX_BUG((__fmt) __VA_OPT__(,) __VA_ARGS__); \
+ } while (0)
+
+/**
+ * RESIZE_ARRAY - Convenience macro for resizing a BPF array
+ * @__skel: the skeleton containing the array
+ * @elfsec: the data section of the BPF program in which the array exists
+ * @arr: the name of the array
+ * @n: the desired array element count
+ *
+ * For BPF arrays declared with RESIZABLE_ARRAY(), this macro performs two
+ * operations. It resizes the map which corresponds to the custom data
+ * section that contains the target array. As a side effect, the BTF info for
+ * the array is adjusted so that the array length is sized to cover the new
+ * data section size. The second operation is reassigning the skeleton pointer
+ * for that custom data section so that it points to the newly memory mapped
+ * region.
+ */
+#define RESIZE_ARRAY(__skel, elfsec, arr, n) \
+ do { \
+ size_t __sz; \
+ bpf_map__set_value_size((__skel)->maps.elfsec##_##arr, \
+ sizeof((__skel)->elfsec##_##arr->arr[0]) * (n)); \
+ (__skel)->elfsec##_##arr = \
+ bpf_map__initial_value((__skel)->maps.elfsec##_##arr, &__sz); \
+ } while (0)
+
+#include "user_exit_info.h"
+#include "compat.h"
+
+#endif /* __SCHED_EXT_COMMON_H */
diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h
new file mode 100644
index 000000000000..3d2fe1208900
--- /dev/null
+++ b/tools/sched_ext/include/scx/compat.bpf.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2024 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2024 David Vernet <dvernet@meta.com>
+ */
+#ifndef __SCX_COMPAT_BPF_H
+#define __SCX_COMPAT_BPF_H
+
+#define __COMPAT_ENUM_OR_ZERO(__type, __ent) \
+({ \
+ __type __ret = 0; \
+ if (bpf_core_enum_value_exists(__type, __ent)) \
+ __ret = __ent; \
+ __ret; \
+})
+
+/*
+ * Define sched_ext_ops. This may be expanded to define multiple variants for
+ * backward compatibility. See compat.h::SCX_OPS_LOAD/ATTACH().
+ */
+#define SCX_OPS_DEFINE(__name, ...) \
+ SEC(".struct_ops.link") \
+ struct sched_ext_ops __name = { \
+ __VA_ARGS__, \
+ };
+
+#endif /* __SCX_COMPAT_BPF_H */
diff --git a/tools/sched_ext/include/scx/compat.h b/tools/sched_ext/include/scx/compat.h
new file mode 100644
index 000000000000..a7fdaf8a858e
--- /dev/null
+++ b/tools/sched_ext/include/scx/compat.h
@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2024 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2024 David Vernet <dvernet@meta.com>
+ */
+#ifndef __SCX_COMPAT_H
+#define __SCX_COMPAT_H
+
+#include <bpf/btf.h>
+
+struct btf *__COMPAT_vmlinux_btf __attribute__((weak));
+
+static inline void __COMPAT_load_vmlinux_btf(void)
+{
+ if (!__COMPAT_vmlinux_btf) {
+ __COMPAT_vmlinux_btf = btf__load_vmlinux_btf();
+ SCX_BUG_ON(!__COMPAT_vmlinux_btf, "btf__load_vmlinux_btf()");
+ }
+}
+
+static inline bool __COMPAT_read_enum(const char *type, const char *name, u64 *v)
+{
+ const struct btf_type *t;
+ const char *n;
+ s32 tid;
+ int i;
+
+ __COMPAT_load_vmlinux_btf();
+
+ tid = btf__find_by_name(__COMPAT_vmlinux_btf, type);
+ if (tid < 0)
+ return false;
+
+ t = btf__type_by_id(__COMPAT_vmlinux_btf, tid);
+ SCX_BUG_ON(!t, "btf__type_by_id(%d)", tid);
+
+ if (btf_is_enum(t)) {
+ struct btf_enum *e = btf_enum(t);
+
+ for (i = 0; i < BTF_INFO_VLEN(t->info); i++) {
+ n = btf__name_by_offset(__COMPAT_vmlinux_btf, e[i].name_off);
+ SCX_BUG_ON(!n, "btf__name_by_offset()");
+ if (!strcmp(n, name)) {
+ *v = e[i].val;
+ return true;
+ }
+ }
+ } else if (btf_is_enum64(t)) {
+ struct btf_enum64 *e = btf_enum64(t);
+
+ for (i = 0; i < BTF_INFO_VLEN(t->info); i++) {
+ n = btf__name_by_offset(__COMPAT_vmlinux_btf, e[i].name_off);
+ SCX_BUG_ON(!n, "btf__name_by_offset()");
+ if (!strcmp(n, name)) {
+ *v = btf_enum64_value(&e[i]);
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+#define __COMPAT_ENUM_OR_ZERO(__type, __ent) \
+({ \
+ u64 __val = 0; \
+ __COMPAT_read_enum(__type, __ent, &__val); \
+ __val; \
+})
+
+static inline bool __COMPAT_has_ksym(const char *ksym)
+{
+ __COMPAT_load_vmlinux_btf();
+ return btf__find_by_name(__COMPAT_vmlinux_btf, ksym) >= 0;
+}
+
+static inline bool __COMPAT_struct_has_field(const char *type, const char *field)
+{
+ const struct btf_type *t;
+ const struct btf_member *m;
+ const char *n;
+ s32 tid;
+ int i;
+
+ __COMPAT_load_vmlinux_btf();
+ tid = btf__find_by_name_kind(__COMPAT_vmlinux_btf, type, BTF_KIND_STRUCT);
+ if (tid < 0)
+ return false;
+
+ t = btf__type_by_id(__COMPAT_vmlinux_btf, tid);
+ SCX_BUG_ON(!t, "btf__type_by_id(%d)", tid);
+
+ m = btf_members(t);
+
+ for (i = 0; i < BTF_INFO_VLEN(t->info); i++) {
+ n = btf__name_by_offset(__COMPAT_vmlinux_btf, m[i].name_off);
+ SCX_BUG_ON(!n, "btf__name_by_offset()");
+ if (!strcmp(n, field))
+ return true;
+ }
+
+ return false;
+}
+
+#define SCX_OPS_SWITCH_PARTIAL \
+ __COMPAT_ENUM_OR_ZERO("scx_ops_flags", "SCX_OPS_SWITCH_PARTIAL")
+
+/*
+ * struct sched_ext_ops can change over time. If compat.bpf.h::SCX_OPS_DEFINE()
+ * is used to define ops and compat.h::SCX_OPS_LOAD/ATTACH() are used to load
+ * and attach it, backward compatibility is automatically maintained where
+ * reasonable.
+ */
+#define SCX_OPS_OPEN(__ops_name, __scx_name) ({ \
+ struct __scx_name *__skel; \
+ \
+ __skel = __scx_name##__open(); \
+ SCX_BUG_ON(!__skel, "Could not open " #__scx_name); \
+ __skel; \
+})
+
+#define SCX_OPS_LOAD(__skel, __ops_name, __scx_name) ({ \
+ SCX_BUG_ON(__scx_name##__load((__skel)), "Failed to load skel"); \
+})
+
+/*
+ * New versions of bpftool now emit additional link placeholders for BPF maps,
+ * and set up BPF skeleton in such a way that libbpf will auto-attach BPF maps
+ * automatically, assumming libbpf is recent enough (v1.5+). Old libbpf will do
+ * nothing with those links and won't attempt to auto-attach maps.
+ *
+ * To maintain compatibility with older libbpf while avoiding trying to attach
+ * twice, disable the autoattach feature on newer libbpf.
+ */
+#if LIBBPF_MAJOR_VERSION > 1 || \
+ (LIBBPF_MAJOR_VERSION == 1 && LIBBPF_MINOR_VERSION >= 5)
+#define __SCX_OPS_DISABLE_AUTOATTACH(__skel, __ops_name) \
+ bpf_map__set_autoattach((__skel)->maps.__ops_name, false)
+#else
+#define __SCX_OPS_DISABLE_AUTOATTACH(__skel, __ops_name) do {} while (0)
+#endif
+
+#define SCX_OPS_ATTACH(__skel, __ops_name, __scx_name) ({ \
+ struct bpf_link *__link; \
+ __SCX_OPS_DISABLE_AUTOATTACH(__skel, __ops_name); \
+ SCX_BUG_ON(__scx_name##__attach((__skel)), "Failed to attach skel"); \
+ __link = bpf_map__attach_struct_ops((__skel)->maps.__ops_name); \
+ SCX_BUG_ON(!__link, "Failed to attach struct_ops"); \
+ __link; \
+})
+
+#endif /* __SCX_COMPAT_H */
diff --git a/tools/sched_ext/include/scx/user_exit_info.h b/tools/sched_ext/include/scx/user_exit_info.h
new file mode 100644
index 000000000000..8c3b7fac4d05
--- /dev/null
+++ b/tools/sched_ext/include/scx/user_exit_info.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Define struct user_exit_info which is shared between BPF and userspace parts
+ * to communicate exit status and other information.
+ *
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2022 David Vernet <dvernet@meta.com>
+ */
+#ifndef __USER_EXIT_INFO_H
+#define __USER_EXIT_INFO_H
+
+enum uei_sizes {
+ UEI_REASON_LEN = 128,
+ UEI_MSG_LEN = 1024,
+};
+
+struct user_exit_info {
+ int kind;
+ s64 exit_code;
+ char reason[UEI_REASON_LEN];
+ char msg[UEI_MSG_LEN];
+};
+
+#ifdef __bpf__
+
+#include "vmlinux.h"
+#include <bpf/bpf_core_read.h>
+
+#define UEI_DEFINE(__name) \
+ struct user_exit_info __name SEC(".data")
+
+#define UEI_RECORD(__uei_name, __ei) ({ \
+ bpf_probe_read_kernel_str(__uei_name.reason, \
+ sizeof(__uei_name.reason), (__ei)->reason); \
+ bpf_probe_read_kernel_str(__uei_name.msg, \
+ sizeof(__uei_name.msg), (__ei)->msg); \
+ if (bpf_core_field_exists((__ei)->exit_code)) \
+ __uei_name.exit_code = (__ei)->exit_code; \
+ /* use __sync to force memory barrier */ \
+ __sync_val_compare_and_swap(&__uei_name.kind, __uei_name.kind, \
+ (__ei)->kind); \
+})
+
+#else /* !__bpf__ */
+
+#include <stdio.h>
+#include <stdbool.h>
+
+#define UEI_EXITED(__skel, __uei_name) ({ \
+ /* use __sync to force memory barrier */ \
+ __sync_val_compare_and_swap(&(__skel)->data->__uei_name.kind, -1, -1); \
+})
+
+#define UEI_REPORT(__skel, __uei_name) ({ \
+ struct user_exit_info *__uei = &(__skel)->data->__uei_name; \
+ fprintf(stderr, "EXIT: %s", __uei->reason); \
+ if (__uei->msg[0] != '\0') \
+ fprintf(stderr, " (%s)", __uei->msg); \
+ fputs("\n", stderr); \
+})
+
+#endif /* __bpf__ */
+#endif /* __USER_EXIT_INFO_H */
diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c
new file mode 100644
index 000000000000..976a2693da71
--- /dev/null
+++ b/tools/sched_ext/scx_qmap.bpf.c
@@ -0,0 +1,264 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * A simple five-level FIFO queue scheduler.
+ *
+ * There are five FIFOs implemented using BPF_MAP_TYPE_QUEUE. A task gets
+ * assigned to one depending on its compound weight. Each CPU round robins
+ * through the FIFOs and dispatches more from FIFOs with higher indices - 1 from
+ * queue0, 2 from queue1, 4 from queue2 and so on.
+ *
+ * This scheduler demonstrates:
+ *
+ * - BPF-side queueing using PIDs.
+ * - Sleepable per-task storage allocation using ops.prep_enable().
+ *
+ * This scheduler is primarily for demonstration and testing of sched_ext
+ * features and unlikely to be useful for actual workloads.
+ *
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2022 David Vernet <dvernet@meta.com>
+ */
+#include <scx/common.bpf.h>
+
+enum consts {
+ ONE_SEC_IN_NS = 1000000000,
+ SHARED_DSQ = 0,
+};
+
+char _license[] SEC("license") = "GPL";
+
+const volatile u64 slice_ns = SCX_SLICE_DFL;
+const volatile u32 dsp_batch;
+
+u32 test_error_cnt;
+
+UEI_DEFINE(uei);
+
+struct qmap {
+ __uint(type, BPF_MAP_TYPE_QUEUE);
+ __uint(max_entries, 4096);
+ __type(value, u32);
+} queue0 SEC(".maps"),
+ queue1 SEC(".maps"),
+ queue2 SEC(".maps"),
+ queue3 SEC(".maps"),
+ queue4 SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+ __uint(max_entries, 5);
+ __type(key, int);
+ __array(values, struct qmap);
+} queue_arr SEC(".maps") = {
+ .values = {
+ [0] = &queue0,
+ [1] = &queue1,
+ [2] = &queue2,
+ [3] = &queue3,
+ [4] = &queue4,
+ },
+};
+
+/* Per-task scheduling context */
+struct task_ctx {
+ bool force_local; /* Dispatch directly to local_dsq */
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
+ __uint(map_flags, BPF_F_NO_PREALLOC);
+ __type(key, int);
+ __type(value, struct task_ctx);
+} task_ctx_stor SEC(".maps");
+
+struct cpu_ctx {
+ u64 dsp_idx; /* dispatch index */
+ u64 dsp_cnt; /* remaining count */
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, u32);
+ __type(value, struct cpu_ctx);
+} cpu_ctx_stor SEC(".maps");
+
+/* Statistics */
+u64 nr_enqueued, nr_dispatched, nr_dequeued;
+
+s32 BPF_STRUCT_OPS(qmap_select_cpu, struct task_struct *p,
+ s32 prev_cpu, u64 wake_flags)
+{
+ struct task_ctx *tctx;
+ s32 cpu;
+
+ tctx = bpf_task_storage_get(&task_ctx_stor, p, 0, 0);
+ if (!tctx) {
+ scx_bpf_error("task_ctx lookup failed");
+ return -ESRCH;
+ }
+
+ if (p->nr_cpus_allowed == 1 ||
+ scx_bpf_test_and_clear_cpu_idle(prev_cpu)) {
+ tctx->force_local = true;
+ return prev_cpu;
+ }
+
+ cpu = scx_bpf_pick_idle_cpu(p->cpus_ptr, 0);
+ if (cpu >= 0)
+ return cpu;
+
+ return prev_cpu;
+}
+
+static int weight_to_idx(u32 weight)
+{
+ /* Coarsely map the compound weight to a FIFO. */
+ if (weight <= 25)
+ return 0;
+ else if (weight <= 50)
+ return 1;
+ else if (weight < 200)
+ return 2;
+ else if (weight < 400)
+ return 3;
+ else
+ return 4;
+}
+
+void BPF_STRUCT_OPS(qmap_enqueue, struct task_struct *p, u64 enq_flags)
+{
+ struct task_ctx *tctx;
+ u32 pid = p->pid;
+ int idx = weight_to_idx(p->scx.weight);
+ void *ring;
+
+ if (test_error_cnt && !--test_error_cnt)
+ scx_bpf_error("test triggering error");
+
+ tctx = bpf_task_storage_get(&task_ctx_stor, p, 0, 0);
+ if (!tctx) {
+ scx_bpf_error("task_ctx lookup failed");
+ return;
+ }
+
+ /* Is select_cpu() is telling us to enqueue locally? */
+ if (tctx->force_local) {
+ tctx->force_local = false;
+ scx_bpf_dispatch(p, SCX_DSQ_LOCAL, slice_ns, enq_flags);
+ return;
+ }
+
+ ring = bpf_map_lookup_elem(&queue_arr, &idx);
+ if (!ring) {
+ scx_bpf_error("failed to find ring %d", idx);
+ return;
+ }
+
+ /* Queue on the selected FIFO. If the FIFO overflows, punt to global. */
+ if (bpf_map_push_elem(ring, &pid, 0)) {
+ scx_bpf_dispatch(p, SHARED_DSQ, slice_ns, enq_flags);
+ return;
+ }
+
+ __sync_fetch_and_add(&nr_enqueued, 1);
+}
+
+/*
+ * The BPF queue map doesn't support removal and sched_ext can handle spurious
+ * dispatches. qmap_dequeue() is only used to collect statistics.
+ */
+void BPF_STRUCT_OPS(qmap_dequeue, struct task_struct *p, u64 deq_flags)
+{
+ __sync_fetch_and_add(&nr_dequeued, 1);
+}
+
+void BPF_STRUCT_OPS(qmap_dispatch, s32 cpu, struct task_struct *prev)
+{
+ struct task_struct *p;
+ struct cpu_ctx *cpuc;
+ u32 zero = 0, batch = dsp_batch ?: 1;
+ void *fifo;
+ s32 i, pid;
+
+ if (scx_bpf_consume(SHARED_DSQ))
+ return;
+
+ if (!(cpuc = bpf_map_lookup_elem(&cpu_ctx_stor, &zero))) {
+ scx_bpf_error("failed to look up cpu_ctx");
+ return;
+ }
+
+ for (i = 0; i < 5; i++) {
+ /* Advance the dispatch cursor and pick the fifo. */
+ if (!cpuc->dsp_cnt) {
+ cpuc->dsp_idx = (cpuc->dsp_idx + 1) % 5;
+ cpuc->dsp_cnt = 1 << cpuc->dsp_idx;
+ }
+
+ fifo = bpf_map_lookup_elem(&queue_arr, &cpuc->dsp_idx);
+ if (!fifo) {
+ scx_bpf_error("failed to find ring %llu", cpuc->dsp_idx);
+ return;
+ }
+
+ /* Dispatch or advance. */
+ bpf_repeat(BPF_MAX_LOOPS) {
+ if (bpf_map_pop_elem(fifo, &pid))
+ break;
+
+ p = bpf_task_from_pid(pid);
+ if (!p)
+ continue;
+
+ __sync_fetch_and_add(&nr_dispatched, 1);
+ scx_bpf_dispatch(p, SHARED_DSQ, slice_ns, 0);
+ bpf_task_release(p);
+ batch--;
+ cpuc->dsp_cnt--;
+ if (!batch || !scx_bpf_dispatch_nr_slots()) {
+ scx_bpf_consume(SHARED_DSQ);
+ return;
+ }
+ if (!cpuc->dsp_cnt)
+ break;
+ }
+
+ cpuc->dsp_cnt = 0;
+ }
+}
+
+s32 BPF_STRUCT_OPS(qmap_init_task, struct task_struct *p,
+ struct scx_init_task_args *args)
+{
+ /*
+ * @p is new. Let's ensure that its task_ctx is available. We can sleep
+ * in this function and the following will automatically use GFP_KERNEL.
+ */
+ if (bpf_task_storage_get(&task_ctx_stor, p, 0,
+ BPF_LOCAL_STORAGE_GET_F_CREATE))
+ return 0;
+ else
+ return -ENOMEM;
+}
+
+s32 BPF_STRUCT_OPS_SLEEPABLE(qmap_init)
+{
+ return scx_bpf_create_dsq(SHARED_DSQ, -1);
+}
+
+void BPF_STRUCT_OPS(qmap_exit, struct scx_exit_info *ei)
+{
+ UEI_RECORD(uei, ei);
+}
+
+SCX_OPS_DEFINE(qmap_ops,
+ .select_cpu = (void *)qmap_select_cpu,
+ .enqueue = (void *)qmap_enqueue,
+ .dequeue = (void *)qmap_dequeue,
+ .dispatch = (void *)qmap_dispatch,
+ .init_task = (void *)qmap_init_task,
+ .init = (void *)qmap_init,
+ .exit = (void *)qmap_exit,
+ .name = "qmap");
diff --git a/tools/sched_ext/scx_qmap.c b/tools/sched_ext/scx_qmap.c
new file mode 100644
index 000000000000..7c84ade7ecfb
--- /dev/null
+++ b/tools/sched_ext/scx_qmap.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2022 David Vernet <dvernet@meta.com>
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <libgen.h>
+#include <bpf/bpf.h>
+#include <scx/common.h>
+#include "scx_qmap.bpf.skel.h"
+
+const char help_fmt[] =
+"A simple five-level FIFO queue sched_ext scheduler.\n"
+"\n"
+"See the top-level comment in .bpf.c for more details.\n"
+"\n"
+"Usage: %s [-s SLICE_US] [-e COUNT] [-b COUNT] [-p] [-v]\n"
+"\n"
+" -s SLICE_US Override slice duration\n"
+" -e COUNT Trigger scx_bpf_error() after COUNT enqueues\n"
+" -b COUNT Dispatch upto COUNT tasks together\n"
+" -p Switch only tasks on SCHED_EXT policy intead of all\n"
+" -v Print libbpf debug messages\n"
+" -h Display this help and exit\n";
+
+static bool verbose;
+static volatile int exit_req;
+
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+ if (level == LIBBPF_DEBUG && !verbose)
+ return 0;
+ return vfprintf(stderr, format, args);
+}
+
+static void sigint_handler(int dummy)
+{
+ exit_req = 1;
+}
+
+int main(int argc, char **argv)
+{
+ struct scx_qmap *skel;
+ struct bpf_link *link;
+ int opt;
+
+ libbpf_set_print(libbpf_print_fn);
+ signal(SIGINT, sigint_handler);
+ signal(SIGTERM, sigint_handler);
+
+ skel = SCX_OPS_OPEN(qmap_ops, scx_qmap);
+
+ while ((opt = getopt(argc, argv, "s:e:b:pvh")) != -1) {
+ switch (opt) {
+ case 's':
+ skel->rodata->slice_ns = strtoull(optarg, NULL, 0) * 1000;
+ break;
+ case 'e':
+ skel->bss->test_error_cnt = strtoul(optarg, NULL, 0);
+ break;
+ case 'b':
+ skel->rodata->dsp_batch = strtoul(optarg, NULL, 0);
+ break;
+ case 'p':
+ skel->struct_ops.qmap_ops->flags |= SCX_OPS_SWITCH_PARTIAL;
+ break;
+ case 'v':
+ verbose = true;
+ break;
+ default:
+ fprintf(stderr, help_fmt, basename(argv[0]));
+ return opt != 'h';
+ }
+ }
+
+ SCX_OPS_LOAD(skel, qmap_ops, scx_qmap);
+ link = SCX_OPS_ATTACH(skel, qmap_ops, scx_qmap);
+
+ while (!exit_req && !UEI_EXITED(skel, uei)) {
+ long nr_enqueued = skel->bss->nr_enqueued;
+ long nr_dispatched = skel->bss->nr_dispatched;
+
+ printf("stats : enq=%lu dsp=%lu delta=%ld deq=%"PRIu64"\n",
+ nr_enqueued, nr_dispatched, nr_enqueued - nr_dispatched,
+ skel->bss->nr_dequeued);
+ fflush(stdout);
+ sleep(1);
+ }
+
+ bpf_link__destroy(link);
+ UEI_REPORT(skel, uei);
+ scx_qmap__destroy(skel);
+ return 0;
+}
diff --git a/tools/sched_ext/scx_simple.bpf.c b/tools/sched_ext/scx_simple.bpf.c
new file mode 100644
index 000000000000..6bb13a3c801b
--- /dev/null
+++ b/tools/sched_ext/scx_simple.bpf.c
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * A simple scheduler.
+ *
+ * A simple global FIFO scheduler. It also demonstrates the following niceties.
+ *
+ * - Statistics tracking how many tasks are queued to local and global dsq's.
+ * - Termination notification for userspace.
+ *
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2022 David Vernet <dvernet@meta.com>
+ */
+#include <scx/common.bpf.h>
+
+char _license[] SEC("license") = "GPL";
+
+UEI_DEFINE(uei);
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(u64));
+ __uint(max_entries, 2); /* [local, global] */
+} stats SEC(".maps");
+
+static void stat_inc(u32 idx)
+{
+ u64 *cnt_p = bpf_map_lookup_elem(&stats, &idx);
+ if (cnt_p)
+ (*cnt_p)++;
+}
+
+s32 BPF_STRUCT_OPS(simple_select_cpu, struct task_struct *p, s32 prev_cpu, u64 wake_flags)
+{
+ bool is_idle = false;
+ s32 cpu;
+
+ cpu = scx_bpf_select_cpu_dfl(p, prev_cpu, wake_flags, &is_idle);
+ if (is_idle) {
+ stat_inc(0); /* count local queueing */
+ scx_bpf_dispatch(p, SCX_DSQ_LOCAL, SCX_SLICE_DFL, 0);
+ }
+
+ return cpu;
+}
+
+void BPF_STRUCT_OPS(simple_enqueue, struct task_struct *p, u64 enq_flags)
+{
+ stat_inc(1); /* count global queueing */
+ scx_bpf_dispatch(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
+}
+
+void BPF_STRUCT_OPS(simple_exit, struct scx_exit_info *ei)
+{
+ UEI_RECORD(uei, ei);
+}
+
+SCX_OPS_DEFINE(simple_ops,
+ .select_cpu = (void *)simple_select_cpu,
+ .enqueue = (void *)simple_enqueue,
+ .exit = (void *)simple_exit,
+ .name = "simple");
diff --git a/tools/sched_ext/scx_simple.c b/tools/sched_ext/scx_simple.c
new file mode 100644
index 000000000000..789ac62fea8e
--- /dev/null
+++ b/tools/sched_ext/scx_simple.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
+ * Copyright (c) 2022 David Vernet <dvernet@meta.com>
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <libgen.h>
+#include <bpf/bpf.h>
+#include <scx/common.h>
+#include "scx_simple.bpf.skel.h"
+
+const char help_fmt[] =
+"A simple sched_ext scheduler.\n"
+"\n"
+"See the top-level comment in .bpf.c for more details.\n"
+"\n"
+"Usage: %s [-v]\n"
+"\n"
+" -v Print libbpf debug messages\n"
+" -h Display this help and exit\n";
+
+static bool verbose;
+static volatile int exit_req;
+
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+ if (level == LIBBPF_DEBUG && !verbose)
+ return 0;
+ return vfprintf(stderr, format, args);
+}
+
+static void sigint_handler(int simple)
+{
+ exit_req = 1;
+}
+
+static void read_stats(struct scx_simple *skel, __u64 *stats)
+{
+ int nr_cpus = libbpf_num_possible_cpus();
+ __u64 cnts[2][nr_cpus];
+ __u32 idx;
+
+ memset(stats, 0, sizeof(stats[0]) * 2);
+
+ for (idx = 0; idx < 2; idx++) {
+ int ret, cpu;
+
+ ret = bpf_map_lookup_elem(bpf_map__fd(skel->maps.stats),
+ &idx, cnts[idx]);
+ if (ret < 0)
+ continue;
+ for (cpu = 0; cpu < nr_cpus; cpu++)
+ stats[idx] += cnts[idx][cpu];
+ }
+}
+
+int main(int argc, char **argv)
+{
+ struct scx_simple *skel;
+ struct bpf_link *link;
+ __u32 opt;
+
+ libbpf_set_print(libbpf_print_fn);
+ signal(SIGINT, sigint_handler);
+ signal(SIGTERM, sigint_handler);
+
+ skel = SCX_OPS_OPEN(simple_ops, scx_simple);
+
+ while ((opt = getopt(argc, argv, "vh")) != -1) {
+ switch (opt) {
+ case 'v':
+ verbose = true;
+ break;
+ default:
+ fprintf(stderr, help_fmt, basename(argv[0]));
+ return opt != 'h';
+ }
+ }
+
+ SCX_OPS_LOAD(skel, simple_ops, scx_simple);
+ link = SCX_OPS_ATTACH(skel, simple_ops, scx_simple);
+
+ while (!exit_req && !UEI_EXITED(skel, uei)) {
+ __u64 stats[2];
+
+ read_stats(skel, stats);
+ printf("local=%llu global=%llu\n", stats[0], stats[1]);
+ fflush(stdout);
+ sleep(1);
+ }
+
+ bpf_link__destroy(link);
+ UEI_REPORT(skel, uei);
+ scx_simple__destroy(skel);
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-12 06:20:00 +0000