[git commit] taskset: add support for taking/printing CPU list (-c option)
Bernhard Reutner-Fischer
rep.dot.nop at gmail.com
Sat Nov 9 01:08:30 UTC 2019
On 1 November 2019 15:44:49 CET, Denys Vlasenko <vda.linux at googlemail.com> wrote:
>commit:
>https://git.busybox.net/busybox/commit/?id=162ac7f45ed0ffdb2fdb2fc1871557523fd22d98
>branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
>
>function old new
>delta
>taskset_main 511 855
>+344
>
>Based on patch by Fryderyk Wrobel <frd1996 at gmail.com>
>
>Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
>---
>util-linux/taskset.c | 129
>++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 118 insertions(+), 11 deletions(-)
>
>diff --git a/util-linux/taskset.c b/util-linux/taskset.c
>index ed8878ad4..cebc20fea 100644
>--- a/util-linux/taskset.c
>+++ b/util-linux/taskset.c
>@@ -20,6 +20,14 @@
> //config: Needed for machines with more than 32-64 CPUs:
>//config: affinity parameter 0xHHHHHHHHHHHHHHHHHHHH can be arbitrarily
>long
> //config: in this case. Otherwise, it is limited to sizeof(long).
>+//config:
>+//config:config FEATURE_TASKSET_CPULIST
>+//config: bool "CPU list support (-c option)"
>+//config: default y
>+//config: depends on FEATURE_TASKSET_FANCY
>+//config: help
>+//config: Add support for taking/printing affinity as CPU list when
>'-c'
>+//config: option is used. For example, it prints '0-3,7' instead of
>mask '8f'.
>
>//applet:IF_TASKSET(APPLET_NOEXEC(taskset, taskset, BB_DIR_USR_BIN,
>BB_SUID_DROP, taskset))
>
>@@ -108,26 +116,109 @@ static unsigned long *get_aff(int pid, unsigned
>*sz)
> return mask;
> }
>
>+#if ENABLE_FEATURE_TASKSET_CPULIST
>+/*
>+ * Parse the CPU list and set the mask accordingly.
>+ *
>+ * The list element can be either a CPU index or a range of CPU
>indices.
>+ * Example: "1,3,5-7".
>+ *
>+ * note1: pattern specifiers after a range (e.g. 0-255:2/64) are not
>supported
Why's that?
Its late here and I'm probably too tired by now but wouldn't just recursing afterwards allow for that to work naturally?
Thanks for beating it into vague sanity either way ;)
Cheers,
>+ * note2: leading/trailing white-spaces are not allowed
>+ */
>+static void parse_cpulist(ul *mask, unsigned max, char *s)
>+{
>+ char *aff = s;
>+ for (;;) {
>+ unsigned bit, end;
>+
>+ bit = end = bb_strtou(s, &s, 10);
>+ if (*s == '-') {
>+ s++;
>+ end = bb_strtou(s, &s, 10);
>+ }
>+ if ((*s != ',' && *s != '\0')
>+ || bit > end
>+ || end == UINT_MAX /* bb_strtou returns this on malformed / ERANGE
>numbers */
>+ ) {
>+ bb_error_msg_and_die("bad affinity '%s'", aff);
>+ }
>+ while (bit <= end && bit < max) {
>+ mask[bit / BITS_UL] |= (1UL << (bit & MASK_UL));
>+ bit++;
>+ }
>+ if (*s == '\0')
>+ break;
>+ s++;
>+ }
>+}
>+static void print_cpulist(const ul *mask, unsigned mask_size_in_bytes)
>+{
>+ const ul *mask_end;
>+ const char *delim;
>+ unsigned pos;
>+ ul bit;
>+
>+ mask_end = mask + mask_size_in_bytes / sizeof(mask[0]);
>+ delim = "";
>+ pos = 0;
>+ bit = 1;
>+ for (;;) {
>+ if (*mask & bit) {
>+ unsigned onebit = pos + 1;
>+ printf("%s%u", delim, pos);
>+ do {
>+ pos++;
>+ bit <<= 1;
>+ if (bit == 0) {
>+ mask++;
>+ if (mask >= mask_end)
>+ break;
>+ bit = 1;
>+ }
>+ } while (*mask & bit);
>+ if (onebit != pos)
>+ printf("-%u", pos - 1);
>+ delim = ",";
>+ }
>+ pos++;
>+ bit <<= 1;
>+ if (bit == 0) {
>+ mask++;
>+ if (mask >= mask_end)
>+ break;
>+ bit = 1;
>+ }
>+ }
>+ bb_putchar('\n');
>+}
>+#endif
>+
> int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
> int taskset_main(int argc UNUSED_PARAM, char **argv)
> {
> ul *mask;
> unsigned mask_size_in_bytes;
> pid_t pid = 0;
>- unsigned opt_p;
> const char *current_new;
> char *aff;
>+ unsigned opts;
>+ enum {
>+ OPT_p = 1 << 0,
>+ OPT_c = (1 << 1) * ENABLE_FEATURE_TASKSET_CPULIST,
>+ };
>
> /* NB: we mimic util-linux's taskset: -p does not take
> * an argument, i.e., "-pN" is NOT valid, only "-p N"!
> * Indeed, util-linux-2.13-pre7 uses:
> * getopt_long(argc, argv, "+pchV", ...), not "...p:..." */
>
>- opt_p = getopt32(argv, "^+" "p" "\0" "-1" /* at least 1 arg */);
>+ opts = getopt32(argv, "^+" "p"IF_FEATURE_TASKSET_CPULIST("c")
>+ "\0" "-1" /* at least 1 arg */);
> argv += optind;
>
> aff = *argv++;
>- if (opt_p) {
>+ if (opts & OPT_p) {
> char *pid_str = aff;
> if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
> pid_str = *argv; /* NB: *argv != NULL in this case */
>@@ -144,8 +235,14 @@ int taskset_main(int argc UNUSED_PARAM, char
>**argv)
> current_new = "current";
> print_aff:
> mask = get_aff(pid, &mask_size_in_bytes);
>- if (opt_p) {
>- printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
>+ if (opts & OPT_p) {
>+#if ENABLE_FEATURE_TASKSET_CPULIST
>+ if (opts & OPT_c) {
>+ printf("pid %d's %s affinity list: ", pid, current_new);
>+ print_cpulist(mask, mask_size_in_bytes);
>+ } else
>+#endif
>+ printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
> pid, current_new, from_mask(mask, mask_size_in_bytes));
> if (*argv == NULL) {
> /* Either it was just "-p <pid>",
>@@ -158,17 +255,27 @@ int taskset_main(int argc UNUSED_PARAM, char
>**argv)
> }
> memset(mask, 0, mask_size_in_bytes);
>
>- /* Affinity was specified, translate it into mask */
>- /* it is always in hex, skip "0x" if it exists */
>- if (aff[0] == '0' && (aff[1]|0x20) == 'x')
>- aff += 2;
>-
> if (!ENABLE_FEATURE_TASKSET_FANCY) {
>+ /* Affinity was specified, translate it into mask */
>+ /* it is always in hex, skip "0x" if it exists */
>+ if (aff[0] == '0' && (aff[1]|0x20) == 'x')
>+ aff += 2;
> mask[0] = xstrtoul(aff, 16);
>- } else {
>+ }
>+#if ENABLE_FEATURE_TASKSET_CPULIST
>+ else if (opts & OPT_c) {
>+ parse_cpulist(mask, mask_size_in_bytes * 8, aff);
>+ }
>+#endif
>+ else {
> unsigned i;
> char *last_char;
>
>+ /* Affinity was specified, translate it into mask */
>+ /* it is always in hex, skip "0x" if it exists */
>+ if (aff[0] == '0' && (aff[1]|0x20) == 'x')
>+ aff += 2;
>+
> i = 0; /* bit pos in mask[] */
>
> /* aff is ASCII hex string, accept very long masks in this form.
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