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95 lines
2.5 KiB
95 lines
2.5 KiB
/* ionice.c - set or get process I/O scheduling class and priority
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*
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* Copyright 2015 Rob Landley <rob@landley.net>
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*
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* It would be really nice if there was a standard, but no. There is
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* Documentation/block/ioprio.txt in the linux source.
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USE_IONICE(NEWTOY(ionice, "^tc#<0>3=2n#<0>7=5p#", TOYFLAG_USR|TOYFLAG_BIN))
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USE_IORENICE(NEWTOY(iorenice, "?<1>3", TOYFLAG_USR|TOYFLAG_BIN))
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config IONICE
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bool "ionice"
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default y
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help
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usage: ionice [-t] [-c CLASS] [-n LEVEL] [COMMAND...|-p PID]
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Change the I/O scheduling priority of a process. With no arguments
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(or just -p), display process' existing I/O class/priority.
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-c CLASS = 1-3: 1(realtime), 2(best-effort, default), 3(when-idle)
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-n LEVEL = 0-7: (0 is highest priority, default = 5)
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-p Affect existing PID instead of spawning new child
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-t Ignore failure to set I/O priority
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System default iopriority is generally -c 2 -n 4.
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config IORENICE
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bool "iorenice"
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default y
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help
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usage: iorenice PID [CLASS] [PRIORITY]
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Display or change I/O priority of existing process. CLASS can be
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"rt" for realtime, "be" for best effort, "idle" for only when idle, or
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"none" to leave it alone. PRIORITY can be 0-7 (0 is highest, default 4).
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*/
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#define FOR_ionice
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#include "toys.h"
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#include <sys/syscall.h>
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GLOBALS(
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long p, n, c;
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)
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static int ioprio_get(void)
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{
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return syscall(__NR_ioprio_get, 1, (int)TT.p);
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}
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static int ioprio_set(void)
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{
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int prio = ((int)TT.c << 13) | (int)TT.n;
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return syscall(__NR_ioprio_set, 1, (int)TT.p, prio);
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}
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void ionice_main(void)
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{
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if (!TT.p && !toys.optc) error_exit("Need -p or COMMAND");
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if (toys.optflags == FLAG_p) {
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int p = ioprio_get();
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xprintf("%s: prio %d\n",
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(char *[]){"unknown", "Realtime", "Best-effort", "Idle"}[(p>>13)&3],
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p&7);
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} else {
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if (-1 == ioprio_set() && !(toys.optflags&FLAG_t)) perror_exit("set");
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if (!TT.p) xexec(toys.optargs);
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}
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}
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void iorenice_main(void)
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{
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char *classes[] = {"none", "rt", "be", "idle"};
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TT.p = atolx(*toys.optargs);
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if (toys.optc == 1) {
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int p = ioprio_get();
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if (p == -1) perror_exit("read priority");
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TT.c = (p>>13)&3;
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p &= 7;
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xprintf("Pid %ld, class %s (%ld), prio %d\n", TT.p, classes[TT.c], TT.c, p);
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return;
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}
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for (TT.c = 0; TT.c<4; TT.c++)
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if (!strcmp(toys.optargs[toys.optc-1], classes[TT.c])) break;
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if (toys.optc == 3 || TT.c == 4) TT.n = atolx(toys.optargs[1]);
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else TT.n = 4;
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TT.c &= 3;
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if (-1 == ioprio_set()) perror_exit("set");
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}
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