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Diffstat (limited to 'schedutils/ionice.c')
| -rw-r--r-- | schedutils/ionice.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/schedutils/ionice.c b/schedutils/ionice.c new file mode 100644 index 0000000..e25428d --- /dev/null +++ b/schedutils/ionice.c @@ -0,0 +1,238 @@ +/* + * ionice: set or get process io scheduling class and priority + * + * Copyright (C) 2005 Jens Axboe <jens@axboe.dk> + * + * Released under the terms of the GNU General Public License version 2 + * + */ +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <getopt.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <ctype.h> + +#include "nls.h" +#include "strutils.h" +#include "c.h" +#include "closestream.h" + +static int tolerant; + +static inline int ioprio_set(int which, int who, int ioprio) +{ + return syscall(SYS_ioprio_set, which, who, ioprio); +} + +static inline int ioprio_get(int which, int who) +{ + return syscall(SYS_ioprio_get, which, who); +} + +enum { + IOPRIO_CLASS_NONE, + IOPRIO_CLASS_RT, + IOPRIO_CLASS_BE, + IOPRIO_CLASS_IDLE, +}; + +enum { + IOPRIO_WHO_PROCESS = 1, + IOPRIO_WHO_PGRP, + IOPRIO_WHO_USER, +}; + +#define IOPRIO_CLASS_SHIFT (13) +#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1) + +#define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT) +#define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_MASK) +#define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) + +const char *to_prio[] = { + [IOPRIO_CLASS_NONE] = "none", + [IOPRIO_CLASS_RT] = "realtime", + [IOPRIO_CLASS_BE] = "best-effort", + [IOPRIO_CLASS_IDLE] = "idle" +}; + +static int parse_ioclass(const char *str) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(to_prio); i++) + if (!strcasecmp(str, to_prio[i])) + return i; + return -1; +} + +static void ioprio_print(int pid) +{ + int ioprio = ioprio_get(IOPRIO_WHO_PROCESS, pid); + + if (ioprio == -1) + err(EXIT_FAILURE, _("ioprio_get failed")); + else { + int ioclass = IOPRIO_PRIO_CLASS(ioprio); + const char *name = _("unknown"); + + if (ioclass > 0 && (size_t) ioclass < ARRAY_SIZE(to_prio)) + name = to_prio[ioclass]; + + if (ioclass != IOPRIO_CLASS_IDLE) + printf("%s: prio %lu\n", name, + IOPRIO_PRIO_DATA(ioprio)); + else + printf("%s\n", name); + } +} + +static void ioprio_setpid(pid_t pid, int ioclass, int data) +{ + int rc = ioprio_set(IOPRIO_WHO_PROCESS, pid, + IOPRIO_PRIO_VALUE(ioclass, data)); + + if (rc == -1 && !tolerant) + err(EXIT_FAILURE, _("ioprio_set failed")); +} + +static void __attribute__ ((__noreturn__)) usage(FILE * out) +{ + fprintf(out, + _("\n" + "%1$s - sets or gets process io scheduling class and priority.\n" + "\n" + "Usage:\n" + " %1$s [OPTION] -p PID [PID...]\n" + " %1$s [OPTION] COMMAND\n" + "\n" + "Options:\n" + " -c, --class <class> scheduling class name or number\n" + " 0: none, 1: realtime, 2: best-effort, 3: idle\n" + " -n, --classdata <num> scheduling class data\n" + " 0-7 for realtime and best-effort classes\n" + " -p, --pid=PID view or modify already running process\n" + " -t, --ignore ignore failures\n" + " -V, --version output version information and exit\n" + " -h, --help display this help and exit\n\n"), + program_invocation_short_name); + + exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); +} + +int main(int argc, char **argv) +{ + int data = 4, set = 0, ioclass = IOPRIO_CLASS_BE, c; + pid_t pid = 0; + + static const struct option longopts[] = { + { "classdata", required_argument, NULL, 'n' }, + { "class", required_argument, NULL, 'c' }, + { "help", no_argument, NULL, 'h' }, + { "ignore", no_argument, NULL, 't' }, + { "pid", required_argument, NULL, 'p' }, + { "version", no_argument, NULL, 'V' }, + { NULL, 0, NULL, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + atexit(close_stdout); + + while ((c = getopt_long(argc, argv, "+n:c:p:tVh", longopts, NULL)) != EOF) + switch (c) { + case 'n': + data = strtos32_or_err(optarg, _("invalid class data argument")); + set |= 1; + break; + case 'c': + if (isdigit(*optarg)) + ioclass = strtos32_or_err(optarg, + _("invalid class argument")); + else { + ioclass = parse_ioclass(optarg); + if (ioclass < 0) + errx(EXIT_FAILURE, + _("unknown scheduling class: '%s'"), + optarg); + } + set |= 2; + break; + case 'p': + pid = strtos32_or_err(optarg, _("invalid PID argument")); + break; + case 't': + tolerant = 1; + break; + case 'V': + printf(_("%s from %s\n"), + program_invocation_short_name, PACKAGE_STRING); + return EXIT_SUCCESS; + case 'h': + usage(stdout); + default: + usage(stderr); + } + + switch (ioclass) { + case IOPRIO_CLASS_NONE: + if ((set & 1) && !tolerant) + warnx(_("ignoring given class data for none class")); + data = 0; + break; + case IOPRIO_CLASS_RT: + case IOPRIO_CLASS_BE: + break; + case IOPRIO_CLASS_IDLE: + if ((set & 1) && !tolerant) + warnx(_("ignoring given class data for idle class")); + data = 7; + break; + default: + if (!tolerant) + warnx(_("unknown prio class %d"), ioclass); + break; + } + + if (!set && !pid && optind == argc) + /* + * ionice without options, print the current ioprio + */ + ioprio_print(0); + + else if (!set && pid) { + /* + * ionice -p PID [PID ...] + */ + ioprio_print(pid); + + for(; argv[optind]; ++optind) { + pid = strtos32_or_err(argv[optind], _("invalid PID argument")); + ioprio_print(pid); + } + } else if (set && pid) { + /* + * ionice -c CLASS -p PID [PID ...] + */ + ioprio_setpid(pid, ioclass, data); + + for(; argv[optind]; ++optind) { + pid = strtos32_or_err(argv[optind], _("invalid PID argument")); + ioprio_setpid(pid, ioclass, data); + } + } else if (argv[optind]) { + /* + * ionice [-c CLASS] COMMAND + */ + ioprio_setpid(0, ioclass, data); + execvp(argv[optind], &argv[optind]); + err(EXIT_FAILURE, _("executing %s failed"), argv[optind]); + } else + usage(stderr); + + + return EXIT_SUCCESS; +} |