1SPANK(8) Slurm Component SPANK(8)
2
6 SPANK - Slurm Plug-in Architecture for Node and job (K)control
7
10 This manual briefly describes the capabilities of the Slurm Plug-in Ar‐
11 chitecture for Node and job Kontrol (SPANK) as well as the SPANK con‐
12 figuration file: (By default: plugstack.conf.)
13 SPANK provides a very generic interface for stackable plug-ins which
15 may be used to dynamically modify the job launch code in Slurm. SPANK
16 plugins may be built without access to Slurm source code. They need
17 only be compiled against Slurm's spank.h header file, added to the
18 SPANK config file plugstack.conf, and they will be loaded at runtime
19 during the next job launch. Thus, the SPANK infrastructure provides ad‐
20 ministrators and other developers a low cost, low effort ability to dy‐
21 namically modify the runtime behavior of Slurm job launch.
22 NOTE: All SPANK plugins should be recompiled when upgrading Slurm to a
24 new major release. The SPANK API is not guaranteed to be ABI compatible
25 between major releases. Any SPANK plugin linking to any of the Slurm
26 libraries should be carefully checked as the Slurm APIs and headers can
27 change between major releases.
28
30 SPANK plugins are loaded in up to five separate contexts during a Slurm
31 job. Briefly, the five contexts are:
32 local In local context, the plugin is loaded by srun. (i.e. the "lo‐
34 cal" part of a parallel job).
35 remote In remote context, the plugin is loaded by slurmstepd. (i.e.
37 the "remote" part of a parallel job).
38 allocator
40 In allocator context, the plugin is loaded in one of the job
41 allocation utilities salloc, sbatch or scrontab.
42 slurmd In slurmd context, the plugin is loaded in the slurmd daemon
44 itself. Note: Plugins loaded in slurmd context persist for the
45 entire time slurmd is running, so if configuration is changed
46 or plugins are updated, slurmd must be restarted for the
47 changes to take effect.
48 job_script
50 In the job_script context, plugins are loaded in the context of
51 the job prolog or epilog. Note: Plugins are loaded in
52 job_script context on each run on the job prolog or epilog, in
53 a separate address space from plugins in slurmd context. This
54 means there is no state shared between this context and other
55 contexts, or even between one call to slurm_spank_job_prolog or
56 slurm_spank_job_epilog and subsequent calls.
57 In local context, only the init, exit, init_post_opt, and lo‐
59 cal_user_init functions are called. In allocator context, only the
60 init, exit, and init_post_opt functions are called. Similarly, in
61 slurmd context, only the init and slurmd_exit callbacks are active, and
62 in the job_script context, only the job_prolog and job_epilog callbacks
63 are used. Plugins may query the context in which they are running with
64 the spank_context and spank_remote functions defined in
65 <slurm/spank.h>.
66 SPANK plugins may be called from multiple points during the Slurm job
68 launch. A plugin may define the following functions:
69 slurm_spank_init
71 Called just after plugins are loaded. In remote context, this is just
72 after job step is initialized. This function is called before any
73 plugin option processing.
74 slurm_spank_job_prolog
76 Called at the same time as the job prolog. If this function returns a
77 non-zero value and the SPANK plugin that contains it is required in
78 the plugstack.conf, the node that this is run on will be drained.
79 slurm_spank_init_post_opt
82 Called at the same point as slurm_spank_init, but after all user op‐
83 tions to the plugin have been processed. The reason that the init and
84 init_post_opt callbacks are separated is so that plugins can process
85 system-wide options specified in plugstack.conf in the init callback,
86 then process user options, and finally take some action in
87 slurm_spank_init_post_opt if necessary. In the case of a heteroge‐
88 neous job, slurm_spank_init is invoked once per job component.
89 slurm_spank_local_user_init
91 Called in local (srun) context only after all options have been pro‐
92 cessed. This is called after the job ID and step IDs are available.
93 This happens in srun after the allocation is made, but before tasks
94 are launched.
95 slurm_spank_user_init
97 Called after privileges are temporarily dropped. (remote context
98 only)
99 slurm_spank_task_init_privileged
101 Called for each task just after fork, but before all elevated privi‐
102 leges are dropped. (remote context only)
103 slurm_spank_task_init
105 Called for each task just before execve (2). If you are restricing
106 memory with cgroups, memory allocated here will be in the job's
107 cgroup. (remote context only)
108 slurm_spank_task_post_fork
110 Called for each task from parent process after fork (2) is complete.
111 Due to the fact that slurmd does not exec any tasks until all tasks
112 have completed fork (2), this call is guaranteed to run before the
113 user task is executed. (remote context only)
114 slurm_spank_task_exit
116 Called for each task as its exit status is collected by Slurm. (re‐
117 mote context only)
118 slurm_spank_exit
120 Called once just before slurmstepd exits in remote context. In local
121 context, called before srun exits.
122 slurm_spank_job_epilog
124 Called at the same time as the job epilog. If this function returns a
125 non-zero value and the SPANK plugin that contains it is required in
126 the plugstack.conf, the node that this is run on will be drained.
127 slurm_spank_slurmd_exit
129 Called in slurmd when the daemon is shut down.
130 All of these functions have the same prototype, for example:
132 int slurm_spank_init (spank_t spank, int ac, char *argv[])
134 Where spank is the SPANK handle which must be passed back to Slurm when
137 the plugin calls functions like spank_get_item and spank_getenv. Con‐
138 figured arguments (See CONFIGURATION below) are passed in the argument
139 vector argv with argument count ac.
140 SPANK plugins can query the current list of supported slurm_spank sym‐
142 bols to determine if the current version supports a given plugin hook.
143 This may be useful because the list of plugin symbols may grow in the
144 future. The query is done using the spank_symbol_supported function,
145 which has the following prototype:
146 int spank_symbol_supported (const char *sym);
148 The return value is 1 if the symbol is supported, 0 if not.
151 SPANK plugins do not have direct access to internally defined Slurm
153 data structures. Instead, information about the currently executing job
154 is obtained via the spank_get_item function call.
155 spank_err_t spank_get_item (spank_t spank, spank_item_t item, ...);
157 The spank_get_item call must be passed the current SPANK handle as well
159 as the item requested, which is defined by the passed spank_item_t. A
160 variable number of pointer arguments are also passed, depending on
161 which item was requested by the plugin. A list of the valid values for
162 item is kept in the spank.h header file. Some examples are:
163 S_JOB_UID
165 User id for running job. (uid_t *) is third arg of spank_get_item
166 S_JOB_STEPID
168 Job step id for running job. (uint32_t *) is third arg of
169 spank_get_item.
170 S_TASK_EXIT_STATUS
172 Exit status for exited task. Only valid from slurm_spank_task_exit.
173 (int *) is third arg of spank_get_item.
174 S_JOB_ARGV
176 Complete job command line. Third and fourth args to spank_get_item
177 are (int *, char ***).
178 See spank.h for more details, and EXAMPLES below for an example of
180 spank_get_item usage.
181 SPANK functions in the local and allocator environment should use the
183 getenv, setenv, and unsetenv functions to view and modify the job's en‐
184 vironment. SPANK functions in the remote environment should use the
185 spank_getenv, spank_setenv, and spank_unsetenv functions to view and
186 modify the job's environment. spank_getenv searches the job's environ‐
187 ment for the environment variable var and copies the current value into
188 a buffer buf of length len. spank_setenv allows a SPANK plugin to set
189 or overwrite a variable in the job's environment, and spank_unsetenv
190 unsets an environment variable in the job's environment. The prototypes
191 are:
192 spank_err_t spank_getenv (spank_t spank, const char *var,
194 char *buf, int len);
195 spank_err_t spank_setenv (spank_t spank, const char *var,
196 const char *val, int overwrite);
197 spank_err_t spank_unsetenv (spank_t spank, const char *var);
198 These are only necessary in remote context since modifications of the
200 standard process environment using setenv (3), getenv (3), and unsetenv
201 (3) may be used in local context.
202 Functions are also available from within the SPANK plugins to establish
204 environment variables to be exported to the Slurm PrologSlurmctld, Pro‐
205 log, Epilog and EpilogSlurmctld programs (the so-called job control en‐
206 vironment). The name of environment variables established by these
207 calls will be prepended with the string SPANK_ in order to avoid any
208 security implications of arbitrary environment variable control. (After
209 all, the job control scripts do run as root or the Slurm user.).
210 These functions are available from local context only.
212 spank_err_t spank_job_control_getenv(spank_t spank, const char *var,
214 char *buf, int len);
215 spank_err_t spank_job_control_setenv(spank_t spank, const char *var,
216 const char *val, int overwrite);
217 spank_err_t spank_job_control_unsetenv(spank_t spank, const char *var);
218 See spank.h for more information, and EXAMPLES below for an example for
220 spank_getenv usage.
221 Many of the described SPANK functions available to plugins return er‐
223 rors via the spank_err_t error type. On success, the return value will
224 be set to ESPANK_SUCCESS, while on failure, the return value will be
225 set to one of many error values defined in slurm/spank.h. The SPANK in‐
226 terface provides a simple function
227 const char * spank_strerror(spank_err_t err);
229 which may be used to translate a spank_err_t value into its string rep‐
231 resentation.
232 The slurm_spank_log function can be used to print messages back to the
235 user at an error level. This is to keep users from having to rely on
236 the slurm_error function, which can be confusing because it prepends
237 "error:" to every message.
238
241 SPANK plugins also have an interface through which they may define and
242 implement extra job options. These options are made available to the
243 user through Slurm commands such as srun(1), salloc(1), and sbatch(1).
244 If the option is specified by the user, its value is forwarded and reg‐
245 istered with the plugin in slurmd when the job is run. In this way,
246 SPANK plugins may dynamically provide new options and functionality to
247 Slurm.
248 Each option registered by a plugin to Slurm takes the form of a struct
250 spank_option which is declared in <slurm/spank.h> as
251 struct spank_option {
253 char * name;
254 char * arginfo;
255 char * usage;
256 int has_arg;
257 int val;
258 spank_opt_cb_f cb;
259 };
260 Where
263 name is the name of the option. Its length is limited to SPANK_OP‐
265 TION_MAXLEN defined in <slurm/spank.h>.
266 arginfo
268 is a description of the argument to the option, if the option
269 does take an argument.
270 usage is a short description of the option suitable for --help output.
272 has_arg
274 0 if option takes no argument, 1 if option takes an argument,
275 and 2 if the option takes an optional argument. (See getopt_long
276 (3)).
277 val A plugin-local value to return to the option callback function.
279 cb A callback function that is invoked when the plugin option is
281 registered with Slurm. spank_opt_cb_f is typedef'd in
282 <slurm/spank.h> as
283 typedef int (*spank_opt_cb_f) (int val, const char *optarg,
285 int remote);
286 Where val is the value of the val field in the spank_option
288 struct, optarg is the supplied argument if applicable, and re‐
289 mote is 0 if the function is being called from the "local" host
290 (e.g. host where srun or sbatch/salloc are invoked) or 1 from
291 the "remote" host (host where slurmd/slurmstepd run) but only
292 executed by slurmstepd (remote context) if the option was regis‐
293 tered for such context.
294 Plugin options may be registered with Slurm using the spank_option_reg‐
296 ister function. This function is only valid when called from the
297 plugin's slurm_spank_init handler, and registers one option at a time.
298 The prototype is
299 spank_err_t spank_option_register (spank_t sp,
301 struct spank_option *opt);
302 This function will return ESPANK_SUCCESS on successful registration of
304 an option, or ESPANK_BAD_ARG for errors including invalid spank_t han‐
305 dle, or when the function is not called from the slurm_spank_init func‐
306 tion. All options need to be registered from all contexts in which they
307 will be used. For instance, if an option is only used in local (srun)
308 and remote (slurmd) contexts, then spank_option_register should only be
309 called from within those contexts. For example:
310 if (spank_context() != S_CTX_ALLOCATOR)
312 spank_option_register (sp, opt);
313 If, however, the option is used in all contexts, the spank_option_reg‐
315 ister needs to be called everywhere.
316 In addition to spank_option_register, plugins may also export options
318 to Slurm by defining a table of struct spank_option with the symbol
319 name spank_options. This method, however, is not supported for use with
320 sbatch and salloc (allocator context), thus the use of spank_op‐
321 tion_register is preferred. When using the spank_options table, the fi‐
322 nal element in the array must be filled with zeros. A SPANK_OPTIONS_TA‐
323 BLE_END macro is provided in <slurm/spank.h> for this purpose.
324 When an option is provided by the user on the local side, either by
326 command line options or by environment variables, Slurm will immedi‐
327 ately invoke the option's callback with remote=0. This is meant for the
328 plugin to do local sanity checking of the option before the value is
329 sent to the remote side during job launch. If the argument the user
330 specified is invalid, the plugin should issue an error and issue a
331 non-zero return code from the callback. The plugin should be able to
332 handle cases where the spank option is set multiple times through envi‐
333 ronment variables and command line options. Environment variables are
334 processed before command line options.
335 On the remote side, options and their arguments are registered just af‐
337 ter SPANK plugins are loaded and before the spank_init handler is
338 called. This allows plugins to modify behavior of all plugin function‐
339 ality based on the value of user-provided options. (See EXAMPLES below
340 for a plugin that registers an option with Slurm).
341 As an alternative to use of an option callback and global variable,
343 plugins can use the spank_option_getopt option to check for supplied
344 options after option processing. This function has the prototype:
345 spank_err_t spank_option_getopt(spank_t sp,
347 struct spank_option *opt, char **optargp);
348 This function returns ESPANK_SUCCESS if the option defined in the
350 struct spank_option opt has been used by the user. If optargp
351 is non-NULL then it is set to any option argument passed (if the option
352 takes an argument). The use of this method is required to process
353 options in job_script context (slurm_spank_job_prolog and
354 slurm_spank_job_epilog). This function is valid in the following contexts:
355 slurm_spank_job_prolog, slurm_spank_local_user_init, slurm_spank_user_init,
356 slurm_spank_task_init_privileged, slurm_spank_task_init, slurm_spank_task_exit,
357 and slurm_spank_job_epilog.
358
361 The default SPANK plug-in stack configuration file is plugstack.conf in
362 the same directory as slurm.conf(5), though this may be changed via the
363 Slurm config parameter PlugStackConfig. Normally the plugstack.conf
364 file should be identical on all nodes of the cluster. The config file
365 lists SPANK plugins, one per line, along with whether the plugin is re‐
366 quired or optional, and any global arguments that are to be passed to
367 the plugin for runtime configuration. Comments are preceded with '#'
368 and extend to the end of the line. If the configuration file is miss‐
369 ing or empty, it will simply be ignored.
370 The format of each non-comment line in the configuration file is:
372 required/optional plugin arguments
374 For example:
376 optional /usr/lib/slurm/test.so
378 Tells slurmd to load the plugin test.so passing no arguments. If a
380 SPANK plugin is required, then failure of any of the plugin's functions
381 will cause slurmd to terminate the job, while optional plugins only
382 cause a warning.
383 If a fully-qualified path is not specified for a plugin, then the cur‐
385 rently configured PluginDir in slurm.conf(5) is searched.
386 SPANK plugins are stackable, meaning that more than one plugin may be
388 placed into the config file. The plugins will simply be called in or‐
389 der, one after the other, and appropriate action taken on failure given
390 that state of the plugin's optional flag.
391 Additional config files or directories of config files may be included
393 in plugstack.conf with the include keyword. The include keyword must
394 appear on its own line, and takes a glob as its parameter, so multiple
395 files may be included from one include line. For example, the following
396 syntax will load all config files in the /etc/slurm/plugstack.conf.d
397 directory, in local collation order:
398 include /etc/slurm/plugstack.conf.d/*
400 which might be considered a more flexible method for building up a
402 spank plugin stack.
403 The SPANK config file is re-read on each job launch, so editing the
405 config file will not affect running jobs. However care should be taken
406 so that a partially edited config file is not read by a launching job.
407
410 When SPANK plugin results in a non-zero result, the following changes
411 will result:
412 ┌──────┬────────────────────────────────┬─────────┬────────┬───────────┬────────┐
415 │Command│Function │Context │Exitcode │Drains Node │Fails job│
416 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
417 │srun │slurm_spank_init │local │1 │no │ yes │
418 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
419 │srun │slurm_spank_init_post_opt │local │1 │no │ yes │
420 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
421 │srun │slurm_spank_local_user_init │local │1 │no │ no │
422 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
423 │srun │slurm_spank_user_init │remote │0 │no │ no │
424 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
425 │srun │slurm_spank_task_init_privileged │remote │1 │no │ yes │
426 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
427 │srun │slurm_spank_task_post_fork │remote │0 │no │ no │
428 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
429 │srun │slurm_spank_task_init │remote │1 │no │ yes │
430 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
431 │srun │slurm_spank_task_exit │remote │0 │no │ no │
432 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
433 │srun │slurm_spank_exit │local │0 │no │ yes │
434 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
435 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
436 │salloc │slurm_spank_init │allocator │1 │no │ yes │
437 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
438 │salloc │slurm_spank_init_post_opt │allocator │1 │no │ yes │
439 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
440 │salloc │slurm_spank_init │local │1 │no │ yes │
441 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
442 │salloc │slurm_spank_init_post_opt │local │1 │no │ yes │
443 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
444 │salloc │slurm_spank_local_user_init │local │1 │no │ yes │
445 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
446 │salloc │slurm_spank_user_init │remote │0 │no │ no │
447 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
448 │salloc │slurm_spank_task_init_privileged │remote │1 │no │ yes │
449 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
450 │salloc │slurm_spank_task_post_fork │remote │0 │no │ no │
451 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
452 │salloc │slurm_spank_task_init │remote │1 │no │ yes │
453 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
454 │salloc │slurm_spank_task_exit │remote │0 │no │ no │
455 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
456 │salloc │slurm_spank_exit │local │0 │no │ yes │
457 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
458 │salloc │slurm_spank_exit │allocator │0 │no │ yes │
459 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
460 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
461 │sbatch │slurm_spank_init │allocator │1 │no │ yes │
462 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
463 │sbatch │slurm_spank_init_post_opt │allocator │1 │no │ yes │
464 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
465 │sbatch │slurm_spank_init │local │1 │no │ yes │
466 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
467 │sbatch │slurm_spank_init_post_opt │local │1 │no │ yes │
468 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
469 │sbatch │slurm_spank_local_user_init │local │1 │no │ yes │
470 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
471 │sbatch │slurm_spank_user_init │remote │0 │yes │ no │
472 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
473 │sbatch │slurm_spank_task_init_privileged │remote │1 │no │ yes │
474 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
475 │sbatch │slurm_spank_task_post_fork │remote │0 │yes │ no │
476 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
477 │sbatch │slurm_spank_task_init │remote │1 │no │ yes │
478 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
479 │sbatch │slurm_spank_task_exit │remote │0 │no │ no │
480 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
481 │sbatch │slurm_spank_exit │local │0 │no │ no │
482 ├──────┼────────────────────────────────┼─────────┼────────┼───────────┼────────┤
483 │sbatch │slurm_spank_exit │allocator │0 │no │ no │
484 └──────┴────────────────────────────────┴─────────┴────────┴───────────┴────────┘
485 NOTE: The behavior for ProctrackType=proctrack/pgid may result in time‐
486 outs for slurm_spank_task_post_fork with remote context on failure.
487
490 /etc/slurm/plugstack.conf:
491 This example plugstack.conf file shows a configuration that ac‐
492 tivates the renice.so SPANK plugin.
493 #
494 # SPANK config file
495 #
496 # required? plugin parameters
497 #
498 optional /usr/lib/SPANK_renice.so min_prio=-10
499 /usr/local/src/renice.c:
501 A sample SPANK plugin to modify the nice value of job tasks.
502 This plugin adds a --renice=[prio] option to srun which users
503 can use to set the priority of all remote tasks. Priority may
504 also be specified via a SLURM_RENICE environment variable. A
505 minimum priority may be established via a "min_prio" parameter
506 in plugstack.conf.
507 #include <sys/types.h>
508 #include <stdio.h>
509 #include <stdlib.h>
510 #include <unistd.h>
511 #include <string.h>
512 #include <sys/resource.h>
513 #include <slurm/spank.h>
515 /*
517 * All spank plugins must define this macro for the
518 * Slurm plugin loader.
519 */
520 SPANK_PLUGIN(renice, 1);
521 #define PRIO_ENV_VAR "SLURM_RENICE"
523 #define PRIO_NOT_SET -1
524 /*
526 * Minimum allowable value for priority. May be
527 * set globally via plugin option min_prio=<prio>
528 */
529 static int min_prio = -20;
530 static int prio = PRIO_NOT_SET;
532 static int _renice_opt_process(int val, const char *optarg, int remote);
534 static int _str2prio(const char *str, int *p2int);
535 /*
537 * Provide a --renice=[prio] option to srun:
538 */
539 struct spank_option spank_options[] =
540 {
541 {
542 "renice",
543 "[prio]",
544 "Re-nice job tasks to priority [prio].",
545 2,
546 0,
547 _renice_opt_process
548 },
549 SPANK_OPTIONS_TABLE_END
550 };
551 /*
553 * Called from both srun and slurmd.
554 */
555 int slurm_spank_init(spank_t sp, int ac, char **av)
556 {
557 int i;
558 /* Don't do anything in sbatch/salloc */
560 if (spank_context () == S_CTX_ALLOCATOR)
561 return ESPANK_SUCCESS;
562 for (i = 0; i < ac; i++) {
564 if (!strncmp("min_prio=", av[i], 9)) {
565 const char *optarg = av[i] + 9;
566 if (_str2prio(optarg, &min_prio))
568 slurm_error ("Ignoring invalid min_prio value: %s", av[i]);
569 } else {
570 slurm_error ("renice: Invalid option: %s", av[i]);
571 }
572 }
573 if (!spank_remote(sp))
575 slurm_verbose("renice: min_prio = %d", min_prio);
576 return ESPANK_SUCCESS;
578 }
579 int slurm_spank_task_post_fork(spank_t sp, int ac, char **av)
581 {
582 int rc;
583 pid_t pid;
584 int taskid;
585 if (prio == PRIO_NOT_SET) {
587 /* See if SLURM_RENICE env var is set by user */
588 char val[1024];
589 rc = spank_getenv(sp, PRIO_ENV_VAR, val, sizeof(val));
591 if (rc)
593 return rc;
594 rc = _str2prio(val, &prio);
596 if (rc) {
598 slurm_error("Bad value for %s: %s", PRIO_ENV_VAR, optarg);
599 return rc;
600 }
601 if (prio < min_prio) {
603 slurm_error("%s=%d not allowed, using min=%d",
604 PRIO_ENV_VAR, prio, min_prio);
605 }
606 }
607 if (prio < min_prio)
609 prio = min_prio;
610 spank_get_item(sp, S_TASK_GLOBAL_ID, &taskid);
612 spank_get_item(sp, S_TASK_PID, &pid);
613 slurm_info("re-nicing task%d pid %d to %d", taskid, (int) pid, prio);
615 if (setpriority(PRIO_PROCESS, (int) pid, (int) prio)) {
617 slurm_error("setpriority: %m");
618 return ESPANK_ERROR;
619 }
620 return ESPANK_SUCCESS;
622 }
623 static int _str2prio(const char *str, int *p2int)
625 {
626 long l;
627 char *p = NULL;
628 if (!str || str[0] == '\0')
630 return ESPANK_BAD_ARG;
631 l = strtol(str, &p, 10);
633 if (!p || (*p != '\0'))
635 return ESPANK_BAD_ARG;
636 if ((l < -20) || (l > 20)) {
638 slurm_error("Specify value between -20 and 20");
639 return ESPANK_BAD_ARG;
640 }
641 *p2int = (int) l;
643 return ESPANK_SUCCESS;
645 }
646 static int _renice_opt_process(int val, const char *optarg, int remote)
648 {
649 int rc;
650 if (optarg == NULL) {
652 slurm_error("renice: invalid NULL argument!");
653 return ESPANK_BAD_ARG;
654 }
655 if ((rc = _str2prio(optarg, &prio))) {
657 slurm_error("Bad value for --renice: %s", optarg);
658 return rc;
659 }
660 if (prio < min_prio) {
662 slurm_error("--renice=%d not allowed, will use min=%d",
663 prio, min_prio);
664 }
665 return ESPANK_SUCCESS;
667 }
668 Compile command:
670 # gcc -ggdb3 -I${SLURM_PATH}/include/ -fPIC -shared -o /usr/lib/SPANK_renice.so /usr/local/src/renice.c
671
674 Portions copyright (C) 2010-2021 SchedMD LLC. Copyright (C) 2006 The
675 Regents of the University of California. Produced at Lawrence Liver‐
676 more National Laboratory (cf, DISCLAIMER). CODE-OCEC-09-009. All
677 rights reserved.
678 This file is part of Slurm, a resource management program. For de‐
680 tails, see <https://slurm.schedmd.com/>.
681 Slurm is free software; you can redistribute it and/or modify it under
683 the terms of the GNU General Public License as published by the Free
684 Software Foundation; either version 2 of the License, or (at your op‐
685 tion) any later version.
686 Slurm is distributed in the hope that it will be useful, but WITHOUT
688 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
689 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
690 for more details.
691
693 /etc/slurm/slurm.conf - Slurm configuration file.
694 /etc/slurm/plugstack.conf - SPANK configuration file.
695 /usr/include/slurm/spank.h - SPANK header file.
696
698 srun(1), slurm.conf(5)
699October 2021 Slurm Component SPANK(8)