From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- tools/perf/tests/subcmd-help.c | 134 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 tools/perf/tests/subcmd-help.c (limited to 'tools/perf/tests/subcmd-help.c') diff --git a/tools/perf/tests/subcmd-help.c b/tools/perf/tests/subcmd-help.c new file mode 100644 index 000000000..9da96a16f --- /dev/null +++ b/tools/perf/tests/subcmd-help.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "tests.h" +#include +#include + +static int test__load_cmdnames(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct cmdnames cmds = {}; + + add_cmdname(&cmds, "aaa", 3); + add_cmdname(&cmds, "foo", 3); + add_cmdname(&cmds, "xyz", 3); + + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds, "aaa") == 1); + TEST_ASSERT_VAL("wrong cmd", is_in_cmdlist(&cmds, "bar") == 0); + TEST_ASSERT_VAL("case sensitive", is_in_cmdlist(&cmds, "XYZ") == 0); + + clean_cmdnames(&cmds); + return TEST_OK; +} + +static int test__uniq_cmdnames(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct cmdnames cmds = {}; + + /* uniq() assumes it's sorted */ + add_cmdname(&cmds, "aaa", 3); + add_cmdname(&cmds, "aaa", 3); + add_cmdname(&cmds, "bbb", 3); + + TEST_ASSERT_VAL("invalid original size", cmds.cnt == 3); + /* uniquify command names (to remove second 'aaa') */ + uniq(&cmds); + TEST_ASSERT_VAL("invalid final size", cmds.cnt == 2); + + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds, "aaa") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds, "bbb") == 1); + TEST_ASSERT_VAL("wrong cmd", is_in_cmdlist(&cmds, "ccc") == 0); + + clean_cmdnames(&cmds); + return TEST_OK; +} + +static int test__exclude_cmdnames(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct cmdnames cmds1 = {}; + struct cmdnames cmds2 = {}; + + add_cmdname(&cmds1, "aaa", 3); + add_cmdname(&cmds1, "bbb", 3); + add_cmdname(&cmds1, "ccc", 3); + add_cmdname(&cmds1, "ddd", 3); + add_cmdname(&cmds1, "eee", 3); + add_cmdname(&cmds1, "fff", 3); + add_cmdname(&cmds1, "ggg", 3); + add_cmdname(&cmds1, "hhh", 3); + add_cmdname(&cmds1, "iii", 3); + add_cmdname(&cmds1, "jjj", 3); + + add_cmdname(&cmds2, "bbb", 3); + add_cmdname(&cmds2, "eee", 3); + add_cmdname(&cmds2, "jjj", 3); + + TEST_ASSERT_VAL("invalid original size", cmds1.cnt == 10); + TEST_ASSERT_VAL("invalid original size", cmds2.cnt == 3); + + /* remove duplicate command names in cmds1 */ + exclude_cmds(&cmds1, &cmds2); + + TEST_ASSERT_VAL("invalid excluded size", cmds1.cnt == 7); + TEST_ASSERT_VAL("invalid excluded size", cmds2.cnt == 3); + + /* excluded commands should not belong to cmds1 */ + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "aaa") == 1); + TEST_ASSERT_VAL("wrong cmd", is_in_cmdlist(&cmds1, "bbb") == 0); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "ccc") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "ddd") == 1); + TEST_ASSERT_VAL("wrong cmd", is_in_cmdlist(&cmds1, "eee") == 0); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "fff") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "ggg") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "hhh") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "iii") == 1); + TEST_ASSERT_VAL("wrong cmd", is_in_cmdlist(&cmds1, "jjj") == 0); + + /* they should be only in cmds2 */ + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds2, "bbb") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds2, "eee") == 1); + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds2, "jjj") == 1); + + clean_cmdnames(&cmds1); + clean_cmdnames(&cmds2); + return TEST_OK; +} + +static int test__exclude_cmdnames_no_overlap(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct cmdnames cmds1 = {}; + struct cmdnames cmds2 = {}; + + add_cmdname(&cmds1, "read-vdso32", 11); + add_cmdname(&cmds2, "archive", 7); + + TEST_ASSERT_VAL("invalid original size", cmds1.cnt == 1); + TEST_ASSERT_VAL("invalid original size", cmds2.cnt == 1); + + exclude_cmds(&cmds1, &cmds2); + + TEST_ASSERT_VAL("invalid excluded size", cmds1.cnt == 1); + TEST_ASSERT_VAL("invalid excluded size", cmds2.cnt == 1); + + TEST_ASSERT_VAL("cannot find cmd", is_in_cmdlist(&cmds1, "read-vdso32") == 1); + TEST_ASSERT_VAL("wrong cmd", is_in_cmdlist(&cmds1, "archive") == 0); + + clean_cmdnames(&cmds1); + clean_cmdnames(&cmds2); + return TEST_OK; +} + +static struct test_case tests__subcmd_help[] = { + TEST_CASE("Load subcmd names", load_cmdnames), + TEST_CASE("Uniquify subcmd names", uniq_cmdnames), + TEST_CASE("Exclude duplicate subcmd names", exclude_cmdnames), + TEST_CASE("Exclude disjoint subcmd names", exclude_cmdnames_no_overlap), + { .name = NULL, } +}; + +struct test_suite suite__subcmd_help = { + .desc = "libsubcmd help tests", + .test_cases = tests__subcmd_help, +}; -- cgit v1.3.1