From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- tools/testing/selftests/sched/.gitignore | 1 + tools/testing/selftests/sched/Makefile | 14 + tools/testing/selftests/sched/config | 1 + tools/testing/selftests/sched/cs_prctl_test.c | 359 ++++++++++++++++++++++++++ 4 files changed, 375 insertions(+) create mode 100644 tools/testing/selftests/sched/.gitignore create mode 100644 tools/testing/selftests/sched/Makefile create mode 100644 tools/testing/selftests/sched/config create mode 100644 tools/testing/selftests/sched/cs_prctl_test.c (limited to 'tools/testing/selftests/sched') diff --git a/tools/testing/selftests/sched/.gitignore b/tools/testing/selftests/sched/.gitignore new file mode 100644 index 000000000..6996d4654 --- /dev/null +++ b/tools/testing/selftests/sched/.gitignore @@ -0,0 +1 @@ +cs_prctl_test diff --git a/tools/testing/selftests/sched/Makefile b/tools/testing/selftests/sched/Makefile new file mode 100644 index 000000000..099ee9213 --- /dev/null +++ b/tools/testing/selftests/sched/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0+ + +ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) +CLANG_FLAGS += -no-integrated-as +endif + +CFLAGS += -O2 -Wall -g -I./ $(KHDR_INCLUDES) -Wl,-rpath=./ \ + $(CLANG_FLAGS) +LDLIBS += -lpthread + +TEST_GEN_FILES := cs_prctl_test +TEST_PROGS := cs_prctl_test + +include ../lib.mk diff --git a/tools/testing/selftests/sched/config b/tools/testing/selftests/sched/config new file mode 100644 index 000000000..1bb8bf6d7 --- /dev/null +++ b/tools/testing/selftests/sched/config @@ -0,0 +1 @@ +# empty diff --git a/tools/testing/selftests/sched/cs_prctl_test.c b/tools/testing/selftests/sched/cs_prctl_test.c new file mode 100644 index 000000000..52d97fae4 --- /dev/null +++ b/tools/testing/selftests/sched/cs_prctl_test.c @@ -0,0 +1,359 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Use the core scheduling prctl() to test core scheduling cookies control. + * + * Copyright (c) 2021 Oracle and/or its affiliates. + * Author: Chris Hyser + * + * + * This library is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License as + * published by the Free Software Foundation. + * + * This library is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License + * for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library; if not, see . + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#if __GLIBC_PREREQ(2, 30) == 0 +#include +static pid_t gettid(void) +{ + return syscall(SYS_gettid); +} +#endif + +#ifndef PR_SCHED_CORE +#define PR_SCHED_CORE 62 +#define PR_SCHED_CORE_GET 0 +#define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ +#define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ +#define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ +#define PR_SCHED_CORE_MAX 4 +#endif + +#define MAX_PROCESSES 128 +#define MAX_THREADS 128 + +static const char USAGE[] = "cs_prctl_test [options]\n" +" options:\n" +" -P : number of processes to create.\n" +" -T : number of threads per process to create.\n" +" -d : delay time to keep tasks alive.\n" +" -k : keep tasks alive until keypress.\n"; + +enum pid_type {PIDTYPE_PID = 0, PIDTYPE_TGID, PIDTYPE_PGID}; + +const int THREAD_CLONE_FLAGS = CLONE_THREAD | CLONE_SIGHAND | CLONE_FS | CLONE_VM | CLONE_FILES; + +struct child_args { + int num_threads; + int pfd[2]; + int cpid; + int thr_tids[MAX_THREADS]; +}; + +static struct child_args procs[MAX_PROCESSES]; +static int num_processes = 2; +static int need_cleanup; + +static int _prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, + unsigned long arg5) +{ + int res; + + res = prctl(option, arg2, arg3, arg4, arg5); + printf("%d = prctl(%d, %ld, %ld, %ld, %lx)\n", res, option, (long)arg2, (long)arg3, + (long)arg4, arg5); + return res; +} + +#define STACK_SIZE (1024 * 1024) + +#define handle_error(msg) __handle_error(__FILE__, __LINE__, msg) +static void __handle_error(char *fn, int ln, char *msg) +{ + int pidx; + printf("(%s:%d) - ", fn, ln); + perror(msg); + if (need_cleanup) { + for (pidx = 0; pidx < num_processes; ++pidx) + kill(procs[pidx].cpid, 15); + need_cleanup = 0; + } + exit(EXIT_FAILURE); +} + +static void handle_usage(int rc, char *msg) +{ + puts(USAGE); + puts(msg); + putchar('\n'); + exit(rc); +} + +static unsigned long get_cs_cookie(int pid) +{ + unsigned long long cookie; + int ret; + + ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, pid, PIDTYPE_PID, + (unsigned long)&cookie); + if (ret) { + printf("Not a core sched system\n"); + return -1UL; + } + + return cookie; +} + +static int child_func_thread(void __attribute__((unused))*arg) +{ + while (1) + usleep(20000); + return 0; +} + +static void create_threads(int num_threads, int thr_tids[]) +{ + void *child_stack; + pid_t tid; + int i; + + for (i = 0; i < num_threads; ++i) { + child_stack = malloc(STACK_SIZE); + if (!child_stack) + handle_error("child stack allocate"); + + tid = clone(child_func_thread, child_stack + STACK_SIZE, THREAD_CLONE_FLAGS, NULL); + if (tid == -1) + handle_error("clone thread"); + thr_tids[i] = tid; + } +} + +static int child_func_process(void *arg) +{ + struct child_args *ca = (struct child_args *)arg; + int ret; + + close(ca->pfd[0]); + + create_threads(ca->num_threads, ca->thr_tids); + + ret = write(ca->pfd[1], &ca->thr_tids, sizeof(int) * ca->num_threads); + if (ret == -1) + printf("write failed on pfd[%d] - error (%s)\n", + ca->pfd[1], strerror(errno)); + + close(ca->pfd[1]); + + while (1) + usleep(20000); + return 0; +} + +static unsigned char child_func_process_stack[STACK_SIZE]; + +void create_processes(int num_processes, int num_threads, struct child_args proc[]) +{ + pid_t cpid; + int i, ret; + + for (i = 0; i < num_processes; ++i) { + proc[i].num_threads = num_threads; + + if (pipe(proc[i].pfd) == -1) + handle_error("pipe() failed"); + + cpid = clone(child_func_process, child_func_process_stack + STACK_SIZE, + SIGCHLD, &proc[i]); + proc[i].cpid = cpid; + close(proc[i].pfd[1]); + } + + for (i = 0; i < num_processes; ++i) { + ret = read(proc[i].pfd[0], &proc[i].thr_tids, sizeof(int) * proc[i].num_threads); + if (ret == -1) + printf("read failed on proc[%d].pfd[0] error (%s)\n", + i, strerror(errno)); + close(proc[i].pfd[0]); + } +} + +void disp_processes(int num_processes, struct child_args proc[]) +{ + int i, j; + + printf("tid=%d, / tgid=%d / pgid=%d: %lx\n", gettid(), getpid(), getpgid(0), + get_cs_cookie(getpid())); + + for (i = 0; i < num_processes; ++i) { + printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].cpid, proc[i].cpid, + getpgid(proc[i].cpid), get_cs_cookie(proc[i].cpid)); + for (j = 0; j < proc[i].num_threads; ++j) { + printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].thr_tids[j], + proc[i].cpid, getpgid(0), get_cs_cookie(proc[i].thr_tids[j])); + } + } + puts("\n"); +} + +static int errors; + +#define validate(v) _validate(__LINE__, v, #v) +void _validate(int line, int val, char *msg) +{ + if (!val) { + ++errors; + printf("(%d) FAILED: %s\n", line, msg); + } else { + printf("(%d) PASSED: %s\n", line, msg); + } +} + +int main(int argc, char *argv[]) +{ + int keypress = 0; + int num_threads = 3; + int delay = 0; + int res = 0; + int pidx; + int pid; + int opt; + + while ((opt = getopt(argc, argv, ":hkT:P:d:")) != -1) { + switch (opt) { + case 'P': + num_processes = (int)strtol(optarg, NULL, 10); + break; + case 'T': + num_threads = (int)strtoul(optarg, NULL, 10); + break; + case 'd': + delay = (int)strtol(optarg, NULL, 10); + break; + case 'k': + keypress = 1; + break; + case 'h': + printf(USAGE); + exit(EXIT_SUCCESS); + default: + handle_usage(20, "unknown option"); + } + } + + if (num_processes < 1 || num_processes > MAX_PROCESSES) + handle_usage(1, "Bad processes value"); + + if (num_threads < 1 || num_threads > MAX_THREADS) + handle_usage(2, "Bad thread value"); + + if (keypress) + delay = -1; + + srand(time(NULL)); + + /* put into separate process group */ + if (setpgid(0, 0) != 0) + handle_error("process group"); + + printf("\n## Create a thread/process/process group hierarchy\n"); + create_processes(num_processes, num_threads, procs); + need_cleanup = 1; + disp_processes(num_processes, procs); + validate(get_cs_cookie(0) == 0); + + printf("\n## Set a cookie on entire process group\n"); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, 0, PIDTYPE_PGID, 0) < 0) + handle_error("core_sched create failed -- PGID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) != 0); + + /* get a random process pid */ + pidx = rand() % num_processes; + pid = procs[pidx].cpid; + + validate(get_cs_cookie(0) == get_cs_cookie(pid)); + validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Set a new cookie on entire process/TGID [%d]\n", pid); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, pid, PIDTYPE_TGID, 0) < 0) + handle_error("core_sched create failed -- TGID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) != get_cs_cookie(pid)); + validate(get_cs_cookie(pid) != 0); + validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Copy the cookie of current/PGID[%d], to pid [%d] as PIDTYPE_PID\n", + getpid(), pid); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, pid, PIDTYPE_PID, 0) < 0) + handle_error("core_sched share to itself failed -- PID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) == get_cs_cookie(pid)); + validate(get_cs_cookie(pid) != 0); + validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Copy cookie from a thread [%d] to current/PGID [%d] as PIDTYPE_PID\n", + procs[pidx].thr_tids[0], getpid()); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, procs[pidx].thr_tids[0], + PIDTYPE_PID, 0) < 0) + handle_error("core_sched share from thread failed -- PID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0])); + validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0])); + + printf("\n## Copy cookie from current [%d] to current as pidtype PGID\n", getpid()); + if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, 0, PIDTYPE_PGID, 0) < 0) + handle_error("core_sched share to self failed -- PGID"); + disp_processes(num_processes, procs); + + validate(get_cs_cookie(0) == get_cs_cookie(pid)); + validate(get_cs_cookie(pid) != 0); + validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0])); + + validate(_prctl(PR_SCHED_CORE, PR_SCHED_CORE_MAX, 0, PIDTYPE_PGID, 0) < 0 + && errno == EINVAL); + + validate(_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, 0, PIDTYPE_PGID, 1) < 0 + && errno == EINVAL); + + if (errors) { + printf("TESTS FAILED. errors: %d\n", errors); + res = 10; + } else { + printf("SUCCESS !!!\n"); + } + + if (keypress) + getchar(); + else + sleep(delay); + + for (pidx = 0; pidx < num_processes; ++pidx) + kill(procs[pidx].cpid, 15); + + return res; +} -- cgit v1.3.1