From 71bc71a7dc2601b1d9beb73ee1f178da1733788e Mon Sep 17 00:00:00 2001 From: Bernhard Reutner-Fischer Date: Fri, 9 Mar 2007 16:56:38 +0000 Subject: [PATCH] - add chrt applet. text data bss dec hex filename 769 0 0 769 301 miscutils/chrt.o and could use some further shrinkage --- include/applets.h | 1 + include/usage.h | 16 ++++++ miscutils/Config.in | 7 +++ miscutils/Kbuild | 1 + miscutils/chrt.c | 124 ++++++++++++++++++++++++++++++++++++++++++++ scripts/defconfig | 1 + 6 files changed, 150 insertions(+) create mode 100644 miscutils/chrt.c diff --git a/include/applets.h b/include/applets.h index d1bf0f36b..214e63aa2 100644 --- a/include/applets.h +++ b/include/applets.h @@ -74,6 +74,7 @@ USE_CHMOD(APPLET(chmod, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_CHOWN(APPLET(chown, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_CHPST(APPLET(chpst, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_CHROOT(APPLET(chroot, _BB_DIR_USR_SBIN, _BB_SUID_NEVER)) +USE_CHRT(APPLET(chrt, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_CHVT(APPLET(chvt, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_CKSUM(APPLET(cksum, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_CLEAR(APPLET(clear, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) diff --git a/include/usage.h b/include/usage.h index d8faa4f12..4d1ecb8f5 100644 --- a/include/usage.h +++ b/include/usage.h @@ -382,6 +382,22 @@ #define bbsh_full_usage \ "The bbsh shell (command interpreter)" +#define chrt_trivial_usage \ + "[OPTION]... [prio] [pid | command [arg]...]" +#define chrt_full_usage \ + "manipulate real-time attributes of a process" \ + "\n\nOptions:\n" \ + " -p operate on pid\n" \ + " -r set scheduling policy to SCHED_RR\n" \ + " -f set scheduling policy to SCHED_FIFO\n" \ + " -o set scheduling policy to SCHED_OTHER\n" \ + " -m show min and max priorities" + +#define chrt_example_usage \ + "$ chrt -r 4 sleep 900 ; x=$!\n" \ + "$ chrt -f -p 3 $x\n" \ + "You need CAP_SYS_NICE privileges to set scheduling attributes of a process" + #define cp_trivial_usage \ "[OPTION]... SOURCE DEST" #define cp_full_usage \ diff --git a/miscutils/Config.in b/miscutils/Config.in index 5afeb2a7e..a1ed24368 100644 --- a/miscutils/Config.in +++ b/miscutils/Config.in @@ -19,6 +19,13 @@ config BBCONFIG The bbconfig applet will print the config file with which busybox was built. +config CHRT + bool "chrt" + default n + help + manipulate real-time attributes of a process. + This requires sched_{g,s}etparam support in your libc. + config CROND bool "crond" default n diff --git a/miscutils/Kbuild b/miscutils/Kbuild index fe147d884..455113764 100644 --- a/miscutils/Kbuild +++ b/miscutils/Kbuild @@ -7,6 +7,7 @@ lib-y:= lib-$(CONFIG_ADJTIMEX) += adjtimex.o lib-$(CONFIG_BBCONFIG) += bbconfig.o +lib-$(CONFIG_CHRT) += chrt.o lib-$(CONFIG_CROND) += crond.o lib-$(CONFIG_CRONTAB) += crontab.o lib-$(CONFIG_DC) += dc.o diff --git a/miscutils/chrt.c b/miscutils/chrt.c new file mode 100644 index 000000000..75d77d536 --- /dev/null +++ b/miscutils/chrt.c @@ -0,0 +1,124 @@ +/* vi: set sw=4 ts=4: */ +/* + * chrt - manipulate real-time attributes of a process + * Copyright (c) 2006-2007 Bernhard Fischer + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include "busybox.h" +#include +#include +#include /* optind */ +#ifndef _POSIX_PRIORITY_SCHEDULING +#warning your system may be foobared +#endif +static const struct { + const int policy; + const char const name[12]; +} policies[] = { + {SCHED_OTHER, "SCHED_OTHER"}, + {SCHED_FIFO, "SCHED_FIFO"}, + {SCHED_RR, "SCHED_RR"} +}; + +static void show_min_max(int pol) { + const char *fmt = "%s min/max priority\t: %d/%d\n\0%s not supported?\n"; + int max, min; + max = sched_get_priority_max(pol); + min = sched_get_priority_min(pol); + if (max >= 0 && min >= 0) + printf(fmt, policies[pol].name, min, max); + else { + fmt += 29; + printf(fmt, policies[pol].name); + } +} + +#define OPT_m (1<<0) +#define OPT_p (1<<1) +#define OPT_r (1<<2) +#define OPT_f (1<<3) +#define OPT_o (1<<4) + +int chrt_main(int argc, char** argv); +int chrt_main(int argc, char** argv) +{ + pid_t pid = 0; + unsigned opt; + struct sched_param sp; + char *p_opt = NULL, *priority = NULL; + const char *state = "current\0new"; + int prio = 0, policy = SCHED_RR; + + opt_complementary = "r--fo:f--ro:r--fo"; /* only one policy accepted */ + opt = getopt32(argc, argv, "+mp:rfo", &p_opt); + if (opt & OPT_r) + policy = SCHED_RR; + if (opt & OPT_f) + policy = SCHED_FIFO; + if (opt & OPT_o) + policy = SCHED_OTHER; + + if (opt & OPT_m) { /* print min/max */ + show_min_max(SCHED_FIFO); + show_min_max(SCHED_RR); + show_min_max(SCHED_OTHER); + fflush_stdout_and_exit(EXIT_SUCCESS); + } + if (opt & OPT_p) { + if (argc == optind+1) { /* -p */ + priority = p_opt; + p_opt = argv[optind]; + } + argv += optind; /* me -p */ + pid = xatoul_range(p_opt, 1, ULONG_MAX); /* -p */ + } else { + argv += optind; /* me -p */ + priority = *argv; + } + if (priority) { + /* from the manpage of sched_getscheduler: + [...] sched_priority can have a value + in the range 0 to 99. + [...] SCHED_OTHER or SCHED_BATCH must be assigned + the static priority 0. [...] SCHED_FIFO or + SCHED_RR can have a static priority in the range 1 to 99. + */ + prio = xstrtol_range(priority, 0, policy == SCHED_OTHER + ? 0 : 1, 99); + } + + if (opt & OPT_p) { + int pol = 0; +print_rt_info: + pol = sched_getscheduler(pid); + if (pol < 0) + bb_perror_msg_and_die("failed to %cet pid %d's policy", 'g', pid); + printf("pid %d's %s scheduling policy: %s\n", + pid, state, policies[pol].name); + if (sched_getparam(pid, &sp)) + bb_perror_msg_and_die("failed to get pid %d's attributes", pid); + printf("pid %d's %s scheduling priority: %d\n", + pid, state, sp.sched_priority); + if (!*argv) /* no new prio given or we did print already, done. */ + return EXIT_SUCCESS; + } + + sp.sched_priority = prio; + if (sched_setscheduler(pid, policy, &sp) < 0) + bb_perror_msg_and_die("failed to %cet pid %d's policy", 's', pid); + if (opt & OPT_p) { + state += 8; + ++argv; + goto print_rt_info; + } + ++argv; + BB_EXECVP(*argv, argv); + bb_perror_msg_and_die("%s", *argv); +} +#undef OPT_p +#undef OPT_r +#undef OPT_f +#undef OPT_o +#undef OPT_m diff --git a/scripts/defconfig b/scripts/defconfig index a3e59c8aa..178db1d74 100644 --- a/scripts/defconfig +++ b/scripts/defconfig @@ -454,6 +454,7 @@ CONFIG_FEATURE_MOUNT_LOOP=y # CONFIG_ADJTIMEX=y # CONFIG_BBCONFIG is not set +CONFIG_CHRT=y CONFIG_CROND=y # CONFIG_DEBUG_CROND_OPTION is not set CONFIG_FEATURE_CROND_CALL_SENDMAIL=y -- 2.25.1