Linux-kselftest-mirror September 2025

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[PATCH v2] KVM: loongarch: selftests: Remove common tests built by TEST_GEN_PROGS_COMMON

by dayss1224＠gmail.com

From: Dong Yang <dayss1224(a)gmail.com> Remove the common KVM test cases already added to TEST_GEN_PROGS_COMMON as following: demand_paging_test dirty_log_test guest_print_test kvm_binary_stats_test kvm_create_max_vcpus kvm_page_table_test set_memory_region_test Fixes: a867688c8cbb ("KVM: selftests: Add supported test cases for LoongArch") Signed-off-by: Quan Zhou <zhouquan(a)iscas.ac.cn> Signed-off-by: Dong Yang <dayss1224(a)gmail.com> Changes in v2: - Add "TEST_GEN_PROGS_loongarch = $(TEST_GEN_PROGS_COMMON)" to include common tests --- tools/testing/selftests/kvm/Makefile.kvm | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 38b95998e1e6..3fd1c2ae68d0 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -198,18 +198,12 @@ TEST_GEN_PROGS_riscv += coalesced_io_test TEST_GEN_PROGS_riscv += get-reg-list TEST_GEN_PROGS_riscv += steal_time +TEST_GEN_PROGS_loongarch = $(TEST_GEN_PROGS_COMMON) TEST_GEN_PROGS_loongarch += coalesced_io_test -TEST_GEN_PROGS_loongarch += demand_paging_test TEST_GEN_PROGS_loongarch += dirty_log_perf_test -TEST_GEN_PROGS_loongarch += dirty_log_test -TEST_GEN_PROGS_loongarch += guest_print_test TEST_GEN_PROGS_loongarch += hardware_disable_test -TEST_GEN_PROGS_loongarch += kvm_binary_stats_test -TEST_GEN_PROGS_loongarch += kvm_create_max_vcpus -TEST_GEN_PROGS_loongarch += kvm_page_table_test TEST_GEN_PROGS_loongarch += memslot_modification_stress_test TEST_GEN_PROGS_loongarch += memslot_perf_test -TEST_GEN_PROGS_loongarch += set_memory_region_test SPLIT_TESTS += arch_timer SPLIT_TESTS += get-reg-list base-commit: b23ff7e52a79f4fe2382e3564719b97b718166d1 -- 2.34.1

3 months, 3 weeks

[PATCHSET V1 0/2] cpuidle, bpf: Introduce BPF-based extensible cpuidle policy via struct_ops

by Lin Yikai

Summary ---------- Hi, everyone, This patch set introduces an extensible cpuidle governor framework using BPF struct_ops, enabling dynamic implementation of idle-state selection policies via BPF programs. Motivation ---------- As is well-known, CPUs support multiple idle states (e.g., C0, C1, C2, ...), where deeper states reduce power consumption, but results in longer wakeup latency, potentially affecting performance. Existing generic cpuidle governors operate effectively in common scenarios but exhibit suboptimal behavior in specific Android phone's use cases. Our testing reveals that during low-utilization scenarios (e.g., screen-off background tasks like music playback with CPU utilization <10%), the C0 state occupies ~50% of idle time, causing significant energy inefficiency. Reducing C0 to ≤20% could yield ≥5% power savings on mobile phones. To address this, we expect: 1.Dynamic governor switching to power-saved policies for low cpu utilization scenarios (e.g., screen-off mode) 2.Dynamic switching to alternate governors for high-performance scenarios (e.g., gaming) OverView ---------- The BPF cpuidle ext governor registers at postcore_initcall() but remains disabled by default due to its low priority "rating" with value "1". Activation requires adjust higer "rating" than other governors within BPF. Core Components: 1.**struct cpuidle_gov_ext_ops** – BPF-overridable operations: - ops.enable()/ops.disable(): enable or disable callback - ops.select(): cpu Idle-state selection logic - ops.set_stop_tick(): Scheduler tick management after state selection - ops.reflect(): feedback info about previous idle state. - ops.init()/ops.deinit(): Initialization or cleanup. 2.**Critical kfuncs for kernel state access**: - bpf_cpuidle_ext_gov_update_rating(): Activate ext governor by raising rating must be called from "ops.init()" - bpf_cpuidle_ext_gov_latency_req(): get idle-state latency constraints - bpf_tick_nohz_get_sleep_length(): get CPU sleep duration in tickless mode Future work ---------- 1. Scenario detection: Identifying low-utilization states (e.g., screen-off + background music) 2. Policy optimization: Optimizing state-selection algorithms for specific scenarios Lin Yikai (2): Subject: [PATCH v1 1/2] cpuidle: Implement BPF extensible cpuidle class Subject: [PATCH v1 2/2] selftests/bpf: Add selftests drivers/cpuidle/Kconfig | 12 + drivers/cpuidle/governors/Makefile | 1 + drivers/cpuidle/governors/ext.c | 537 ++++++++++++++++++ .../bpf/prog_tests/test_cpuidle_gov_ext.c | 28 + .../selftests/bpf/progs/cpuidle_gov_ext.c | 208 +++++++ 5 files changed, 786 insertions(+) create mode 100644 drivers/cpuidle/governors/ext.c create mode 100644 tools/testing/selftests/bpf/prog_tests/test_cpuidle_gov_ext.c create mode 100644 tools/testing/selftests/bpf/progs/cpuidle_gov_ext.c -- 2.43.0

3 months, 3 weeks

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Linux-kselftest-mirror September 2025