Hi Thijs,
On Wed, Mar 27, 2024 at 01:43:21PM +0100 Thijs Raymakers wrote:
> Signed-off-by: Thijs Raymakers <thijs@xxxxxxxxxxxx>
> Thanks: Phil Auld for the valuable feedback
> ---
> .gitignore | 1 +
> bash-completion/coresched | 0
> configure.ac | 12 +-
> meson.build | 16 +-
> meson_options.txt | 2 +-
> schedutils/Makemodule.am | 8 +
> schedutils/coresched.1.adoc | 16 ++
> schedutils/coresched.c | 363 ++++++++++++++++++++++++++++++++++++
> 8 files changed, 412 insertions(+), 6 deletions(-)
> create mode 100644 bash-completion/coresched
> create mode 100644 schedutils/coresched.1.adoc
> create mode 100644 schedutils/coresched.c
>
> diff --git a/.gitignore b/.gitignore
> index 6ecbfa7fe..316f3cdcc 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -94,6 +94,7 @@ ylwrap
> /colcrt
> /colrm
> /column
> +/coresched
> /ctrlaltdel
> /delpart
> /dmesg
> diff --git a/bash-completion/coresched b/bash-completion/coresched
> new file mode 100644
> index 000000000..e69de29bb
> diff --git a/configure.ac b/configure.ac
> index ab7c98636..3a189a075 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -2500,9 +2500,9 @@ UL_REQUIRES_HAVE([setterm], [ncursesw, ncurses], [ncursesw or ncurses library])
> AM_CONDITIONAL([BUILD_SETTERM], [test "x$build_setterm" = xyes])
>
> # build_schedutils= is just configure-only variable to control
> -# ionice, taskset and chrt
> +# ionice, taskset, coresched and chrt
> AC_ARG_ENABLE([schedutils],
> - AS_HELP_STRING([--disable-schedutils], [do not build chrt, ionice, taskset]),
> + AS_HELP_STRING([--disable-schedutils], [do not build chrt, ionice, taskset, coresched]),
> [], [UL_DEFAULT_ENABLE([schedutils], [check])]
> )
>
> @@ -2545,6 +2545,14 @@ UL_REQUIRES_SYSCALL_CHECK([taskset],
> AM_CONDITIONAL([BUILD_TASKSET], [test "x$build_taskset" = xyes])
>
>
> +UL_ENABLE_ALIAS([coresched], [schedutils])
> +UL_BUILD_INIT([coresched])
> +UL_REQUIRES_SYSCALL_CHECK([coresched],
> + [UL_CHECK_SYSCALL([prctl])],
> + [prctl])
> +AM_CONDITIONAL([BUILD_CORESCHED], [test "x$build_coresched" = xyes])
> +
> +
> have_schedsetter=no
> AS_IF([test "x$ac_cv_func_sched_setscheduler" = xyes], [have_schedsetter=yes],
> [test "x$ac_cv_func_sched_setattr" = xyes], [have_schedsetter=yes])
> diff --git a/meson.build b/meson.build
> index 9600ce49f..9a2c04e8f 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -3111,13 +3111,23 @@ exe4 = executable(
> install : opt,
> build_by_default : opt)
>
> +exe5 = executable(
> + 'coresched',
> + 'schedutils/coresched.c',
> + include_directories : includes,
> + link_with : lib_common,
> + install_dir : usrbin_exec_dir,
> + install : opt,
> + build_by_default : opt)
> +
> if opt and not is_disabler(exe)
> - exes += [exe, exe2, exe3, exe4]
> + exes += [exe, exe2, exe3, exe4, exe5]
> manadocs += ['schedutils/chrt.1.adoc',
> 'schedutils/ionice.1.adoc',
> 'schedutils/taskset.1.adoc',
> - 'schedutils/uclampset.1.adoc']
> - bashcompletions += ['chrt', 'ionice', 'taskset', 'uclampset']
> + 'schedutils/uclampset.1.adoc',
> + 'schedutils/coresched.1.adoc']
> + bashcompletions += ['chrt', 'ionice', 'taskset', 'uclampset', 'coresched']
> endif
>
> ############################################################
> diff --git a/meson_options.txt b/meson_options.txt
> index 7b8cf3f35..3405c1b73 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -162,7 +162,7 @@ option('build-pipesz', type : 'feature',
> option('build-setterm', type : 'feature',
> description : 'build setterm')
> option('build-schedutils', type : 'feature',
> - description : 'build chrt, ionice, taskset')
> + description : 'build chrt, ionice, taskset, coresched')
> option('build-wall', type : 'feature',
> description : 'build wall')
> option('build-write', type : 'feature',
> diff --git a/schedutils/Makemodule.am b/schedutils/Makemodule.am
> index 1040da85f..0cb655401 100644
> --- a/schedutils/Makemodule.am
> +++ b/schedutils/Makemodule.am
> @@ -29,3 +29,11 @@ dist_noinst_DATA += schedutils/uclampset.1.adoc
> uclampset_SOURCES = schedutils/uclampset.c schedutils/sched_attr.h
> uclampset_LDADD = $(LDADD) libcommon.la
> endif
> +
> +if BUILD_CORESCHED
> +usrbin_exec_PROGRAMS += coresched
> +MANPAGES += schedutils/coresched.1
> +dist_noinst_DATA += schedutils/coresched.1.adoc
> +coresched_SOURCES = schedutils/coresched.c
> +coresched_LDADD = $(LDADD) libcommon.la
> +endif
> diff --git a/schedutils/coresched.1.adoc b/schedutils/coresched.1.adoc
> new file mode 100644
> index 000000000..60a21cd01
> --- /dev/null
> +++ b/schedutils/coresched.1.adoc
> @@ -0,0 +1,16 @@
> +//po4a: entry man manual
> +////
> +coresched(1) manpage
> +////
> += coresched(1)
> +:doctype: manpage
> +:man manual: User Commands
> +:man source: util-linux {release-version}
> +:page-layout: base
> +:command: coresched
> +:colon: :
> +:copyright: ©
> +
> +== NAME
> +
> +coresched - manage core scheduling cookies for tasks
> diff --git a/schedutils/coresched.c b/schedutils/coresched.c
> new file mode 100644
> index 000000000..537281fdb
> --- /dev/null
> +++ b/schedutils/coresched.c
> @@ -0,0 +1,363 @@
> +/**
> + * SPDX-License-Identifier: EUPL-1.2
> + *
> + * coresched.c - manage core scheduling cookies for tasks
> + *
> + * Copyright (C) 2024 Thijs Raymakers
> + * Licensed under the EUPL v1.2
> + */
> +
> +#include <getopt.h>
> +#include <stdbool.h>
> +#include <stdio.h>
> +#include <sys/prctl.h>
> +#include <sys/wait.h>
> +#include <unistd.h>
> +
> +#include "c.h"
> +#include "closestream.h"
> +#include "nls.h"
> +#include "optutils.h"
> +#include "strutils.h"
> +
I think you need to do a similar #ifdef game
as below, with all the PR_SCHED_CORE* macros as well.
On a system with an older prctl.h this just fails to build.
There is no reason it needs to though since these
are just numbers.
Alternatively the configure system needs to check and disable
the program but that does not seem necessary to me.
Cheers,
Phil
> +// These definitions might not be defined, even if the
> +// prctl interface accepts them.
> +#ifndef PR_SCHED_CORE_SCOPE_THREAD
> +#define PR_SCHED_CORE_SCOPE_THREAD 0
> +#endif
> +#ifndef PR_SCHED_CORE_SCOPE_THREAD_GROUP
> +#define PR_SCHED_CORE_SCOPE_THREAD_GROUP 1
> +#endif
> +
> +#ifndef PR_SCHED_CORE_SCOPE_PROCESS_GROUP
> +#define PR_SCHED_CORE_SCOPE_PROCESS_GROUP 2
> +#endif
> +
> +typedef int core_sched_type_t;
> +typedef unsigned long cookie_t;
> +typedef enum {
> + SCHED_CORE_CMD_GET,
> + SCHED_CORE_CMD_NEW,
> + SCHED_CORE_CMD_COPY,
> +} core_sched_cmd_t;
> +
> +struct args {
> + pid_t pid;
> + pid_t dest;
> + core_sched_type_t type;
> + core_sched_cmd_t cmd;
> + int exec_argv_offset;
> +};
> +
> +cookie_t core_sched_get_cookie(pid_t pid);
> +void core_sched_create_cookie(pid_t pid, core_sched_type_t type);
> +void core_sched_pull_cookie(pid_t from);
> +void core_sched_push_cookie(pid_t to, core_sched_type_t type);
> +void core_sched_copy_cookie(pid_t from, pid_t to, core_sched_type_t to_type);
> +void core_sched_exec_with_cookie(struct args *args, char **argv);
> +void core_sched_get_and_print_cookie(pid_t pid);
> +
> +core_sched_type_t parse_core_sched_type(char *str);
> +bool verify_arguments(struct args *args);
> +void parse_arguments(int argc, char **argv, struct args *args);
> +void set_pid_or_err(pid_t *dest, pid_t src, const char *err_msg);
> +static void __attribute__((__noreturn__)) usage(void);
> +
> +#define bad_usage(FMT...) \
> + warnx(FMT); \
> + errtryhelp(EINVAL);
> +
> +#define check_coresched_in_kernel(errno) \
> + if (errno == EINVAL) { \
> + warnx("Does your kernel support CONFIG_SCHED_CORE?"); \
> + }
> +
> +cookie_t core_sched_get_cookie(pid_t pid)
> +{
> + cookie_t cookie = 0;
> + if (prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, pid,
> + PR_SCHED_CORE_SCOPE_THREAD, &cookie)) {
> + check_coresched_in_kernel(errno);
> + err(errno, "Failed to get cookie from PID %d", pid);
> + }
> + return cookie;
> +}
> +
> +void core_sched_create_cookie(pid_t pid, core_sched_type_t type)
> +{
> + if (prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, pid, type, 0)) {
> + check_coresched_in_kernel(errno);
> + err(errno, "Failed to create cookie for PID %d", pid);
> + }
> +}
> +
> +void core_sched_pull_cookie(pid_t from)
> +{
> + if (prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, from,
> + PR_SCHED_CORE_SCOPE_THREAD, 0)) {
> + check_coresched_in_kernel(errno);
> + err(errno, "Failed to pull cookie from PID %d", from);
> + }
> +}
> +
> +void core_sched_push_cookie(pid_t to, core_sched_type_t type)
> +{
> + if (prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, to, type, 0)) {
> + check_coresched_in_kernel(errno);
> + err(errno, "Failed to push cookie to PID %d", to);
> + }
> +}
> +
> +void core_sched_copy_cookie(pid_t from, pid_t to, core_sched_type_t to_type)
> +{
> + core_sched_pull_cookie(from);
> + cookie_t before = core_sched_get_cookie(from);
> + core_sched_push_cookie(to, to_type);
> + printf("%s: copied cookie 0x%lx from PID %d to PID %d\n",
> + program_invocation_short_name, before, from, to);
> +}
> +
> +void core_sched_exec_with_cookie(struct args *args, char **argv)
> +{
> + if (!args->exec_argv_offset) {
> + usage();
> + }
> +
> + // Move the argument list to the first argument of the program
> + argv = &argv[args->exec_argv_offset];
> +
> + // If a source PID is provided, try to copy the cookie from
> + // that PID. Otherwise, create a brand new cookie with the
> + // provided type.
> + if (args->pid) {
> + core_sched_pull_cookie(args->pid);
> + core_sched_get_and_print_cookie(args->pid);
> + } else {
> + pid_t pid = getpid();
> + core_sched_create_cookie(pid, args->type);
> + cookie_t after = core_sched_get_cookie(pid);
> + printf("%s: set cookie of PID %d to 0x%lx\n",
> + program_invocation_short_name, pid, after);
> + }
> +
> + if (execvp(argv[0], argv)) {
> + errexec(argv[0]);
> + }
> +}
> +
> +void core_sched_get_and_print_cookie(pid_t pid)
> +{
> + cookie_t after = core_sched_get_cookie(pid);
> + printf("%s: set cookie of PID %d to 0x%lx\n",
> + program_invocation_short_name, pid, after);
> +}
> +
> +core_sched_type_t parse_core_sched_type(char *str)
> +{
> + if (!strncmp(str, "pid\0", 4)) {
> + return PR_SCHED_CORE_SCOPE_THREAD;
> + } else if (!strncmp(str, "tgid\0", 5)) {
> + return PR_SCHED_CORE_SCOPE_THREAD_GROUP;
> + } else if (!strncmp(str, "pgid\0", 5)) {
> + return PR_SCHED_CORE_SCOPE_PROCESS_GROUP;
> + }
> +
> + bad_usage("'%s' is an invalid option. Must be one of pid/tgid/pgid",
> + str);
> + __builtin_unreachable();
> +}
> +
> +static void __attribute__((__noreturn__)) usage(void)
> +{
> + fputs(USAGE_HEADER, stdout);
> + fprintf(stdout, _(" %s [-p PID]\n"), program_invocation_short_name);
> + fprintf(stdout, _(" %s --new [-t <TYPE>] -p <PID>\n"),
> + program_invocation_short_name);
> + fprintf(stdout, _(" %s --new [-t <TYPE>] -- PROGRAM [ARGS...]\n"),
> + program_invocation_short_name);
> + fprintf(stdout, _(" %s --copy -p <PID> [-t <TYPE>] -d <PID>\n"),
> + program_invocation_short_name);
> + fprintf(stdout,
> + _(" %s --copy -p <PID> [-t <TYPE>] -- PROGRAM [ARGS...]\n"),
> + program_invocation_short_name);
> +
> + fputs(USAGE_SEPARATOR, stdout);
> + fputsln(_("Manage core scheduling cookies for tasks."), stdout);
> +
> + fputs(USAGE_FUNCTIONS, stdout);
> + fputsln(_(" -n, --new assign a new core scheduling cookie to an existing PID or\n"
> + " execute a program with a new cookie."),
> + stdout);
> + fputsln(_(" -c, --copy copy the core scheduling cookie from an existing PID to\n"
> + " either another PID, or copy it to a new program"),
> + stdout);
> + fputsln(_("\n If no function is provided, it will retrieve and print the cookie from\n"
> + " the PID provided via --pid.\n"),
> + stdout);
> +
> + fputs(USAGE_OPTIONS, stdout);
> + fputsln(_(" -p, --pid <PID> operate on an existing PID"), stdout);
> + fputsln(_(" -d, --dest <PID> when copying a cookie from an existing PID, --dest is\n"
> + " the destination PID where to copy the cookie to."),
> + stdout);
> + fputsln(_(" -t, --type <TYPE> type of the destination PID, or the type of the PID\n"
> + " when a new core scheduling cookie is created.\n"
> + " Can be one of the following: pid, tgid or pgid.\n"
> + " The default is tgid."),
> + stdout);
> + fputs(USAGE_SEPARATOR, stdout);
> + fprintf(stdout,
> + USAGE_HELP_OPTIONS(
> + 20)); /* char offset to align option descriptions */
> + fprintf(stdout, USAGE_MAN_TAIL("coresched(1)"));
> + exit(EXIT_SUCCESS);
> +}
> +
> +void parse_arguments(int argc, char **argv, struct args *args)
> +{
> + int c;
> +
> + static const struct option longopts[] = {
> + { "new", no_argument, NULL, 'n' },
> + { "copy", no_argument, NULL, 'c' },
> + { "pid", required_argument, NULL, 'p' },
> + { "dest", required_argument, NULL, 'd' },
> + { "type", required_argument, NULL, 't' },
> + { "version", no_argument, NULL, 'V' },
> + { "help", no_argument, NULL, 'h' },
> + { NULL, 0, NULL, 0 }
> + };
> + static const ul_excl_t excl[] = {
> + { 'c', 'n' }, // Cannot do both --new and --copy
> + { 'd', 'n' }, // Cannot have both --new and --dest
> + { 0 }
> + };
> +
> + int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
> +
> + while ((c = getopt_long(argc, argv, "ncp:d:t:Vh", longopts, NULL)) !=
> + -1) {
> + err_exclusive_options(c, longopts, excl, excl_st);
> + switch (c) {
> + case 'n':
> + args->cmd = SCHED_CORE_CMD_NEW;
> + break;
> + case 'c':
> + args->cmd = SCHED_CORE_CMD_COPY;
> + break;
> + case 'p':
> + args->pid = strtopid_or_err(
> + optarg, "Failed to parse PID for -p/--pid");
> + break;
> + case 'd':
> + args->dest = strtopid_or_err(
> + optarg, "Failed to parse PID for -d/--dest");
> + break;
> + case 't':
> + args->type = parse_core_sched_type(optarg);
> + break;
> + case 'V':
> + print_version(EXIT_SUCCESS);
> + case 'h':
> + usage();
> + default:
> + errtryhelp(EXIT_FAILURE);
> + }
> + }
> +
> + if (args->cmd == SCHED_CORE_CMD_COPY && !args->pid) {
> + bad_usage("--copy: requires a -p/--pid");
> + }
> +
> + // More arguments have been passed, which means that the user wants to run
> + // another program with a core scheduling cookie.
> + if (argc > optind) {
> + switch (args->cmd) {
> + case SCHED_CORE_CMD_GET:
> + bad_usage("Unknown command");
> + break;
> + case SCHED_CORE_CMD_NEW:
> + if (args->pid) {
> + bad_usage(
> + "--new: cannot accept both a -p/--pid and a command");
> + } else {
> + args->exec_argv_offset = optind;
> + }
> + break;
> + case SCHED_CORE_CMD_COPY:
> + if (args->dest) {
> + bad_usage(
> + "--copy: cannot accept both a destination PID "
> + "-d/--dest and a command")
> + } else {
> + args->exec_argv_offset = optind;
> + }
> + break;
> + }
> + }
> +
> + if (argc <= optind) {
> + if (args->cmd == SCHED_CORE_CMD_NEW && !args->pid) {
> + bad_usage(
> + "--new: requires either a -p/--pid or a command");
> + }
> + if (args->cmd == SCHED_CORE_CMD_COPY && !args->dest) {
> + bad_usage(
> + "--copy: requires either a -d/--dest or a command");
> + }
> + }
> +}
> +
> +int main(int argc, char **argv)
> +{
> + struct args args = { 0 };
> + args.cmd = SCHED_CORE_CMD_GET;
> + args.type = PR_SCHED_CORE_SCOPE_THREAD_GROUP;
> +
> + setlocale(LC_ALL, "");
> + bindtextdomain(PACKAGE, LOCALEDIR);
> + textdomain(PACKAGE);
> + close_stdout_atexit();
> +
> + parse_arguments(argc, argv, &args);
> +
> + cookie_t cookie = 0;
> +
> + switch (args.cmd) {
> + case SCHED_CORE_CMD_GET:
> + if (args.pid) {
> + cookie = core_sched_get_cookie(args.pid);
> + if (cookie) {
> + printf("%s: cookie of pid %d is 0x%lx\n",
> + program_invocation_short_name, args.pid,
> + cookie);
> + } else {
> + errx(ENODATA,
> + "pid %d doesn't have a core scheduling cookie",
> + args.pid);
> + }
> + } else {
> + usage();
> + exit(0);
> + }
> + break;
> + case SCHED_CORE_CMD_NEW:
> + if (args.pid) {
> + core_sched_create_cookie(args.pid, args.type);
> + core_sched_get_and_print_cookie(args.pid);
> + } else {
> + core_sched_exec_with_cookie(&args, argv);
> + }
> + break;
> + case SCHED_CORE_CMD_COPY:
> + if (args.dest) {
> + core_sched_copy_cookie(args.pid, args.dest, args.type);
> + } else {
> + core_sched_exec_with_cookie(&args, argv);
> + }
> + break;
> + default:
> + usage();
> + exit(1);
> + }
> +}
> --
> 2.44.0
>
--
