4 * Processor and Memory placement constraints for sets of tasks.
6 * Copyright (C) 2003 BULL SA.
7 * Copyright (C) 2004 Silicon Graphics, Inc.
9 * Portions derived from Patrick Mochel's sysfs code.
10 * sysfs is Copyright (c) 2001-3 Patrick Mochel
11 * Portions Copyright (c) 2004 Silicon Graphics, Inc.
13 * 2003-10-10 Written by Simon Derr <simon.derr@bull.net>
14 * 2003-10-22 Updates by Stephen Hemminger.
15 * 2004 May-July Rework by Paul Jackson <pj@sgi.com>
17 * This file is subject to the terms and conditions of the GNU General Public
18 * License. See the file COPYING in the main directory of the Linux
19 * distribution for more details.
22 #include <linux/config.h>
23 #include <linux/cpu.h>
24 #include <linux/cpumask.h>
25 #include <linux/cpuset.h>
26 #include <linux/err.h>
27 #include <linux/errno.h>
28 #include <linux/file.h>
30 #include <linux/init.h>
31 #include <linux/interrupt.h>
32 #include <linux/kernel.h>
33 #include <linux/kmod.h>
34 #include <linux/list.h>
36 #include <linux/module.h>
37 #include <linux/mount.h>
38 #include <linux/namei.h>
39 #include <linux/pagemap.h>
40 #include <linux/proc_fs.h>
41 #include <linux/sched.h>
42 #include <linux/seq_file.h>
43 #include <linux/slab.h>
44 #include <linux/smp_lock.h>
45 #include <linux/spinlock.h>
46 #include <linux/stat.h>
47 #include <linux/string.h>
48 #include <linux/time.h>
49 #include <linux/backing-dev.h>
50 #include <linux/sort.h>
52 #include <asm/uaccess.h>
53 #include <asm/atomic.h>
54 #include <asm/semaphore.h>
56 #define CPUSET_SUPER_MAGIC 0x27e0eb
59 unsigned long flags
; /* "unsigned long" so bitops work */
60 cpumask_t cpus_allowed
; /* CPUs allowed to tasks in cpuset */
61 nodemask_t mems_allowed
; /* Memory Nodes allowed to tasks */
63 atomic_t count
; /* count tasks using this cpuset */
66 * We link our 'sibling' struct into our parents 'children'.
67 * Our children link their 'sibling' into our 'children'.
69 struct list_head sibling
; /* my parents children */
70 struct list_head children
; /* my children */
72 struct cpuset
*parent
; /* my parent */
73 struct dentry
*dentry
; /* cpuset fs entry */
76 * Copy of global cpuset_mems_generation as of the most
77 * recent time this cpuset changed its mems_allowed.
82 /* bits in struct cpuset flags field */
90 /* convenient tests for these bits */
91 static inline int is_cpu_exclusive(const struct cpuset
*cs
)
93 return !!test_bit(CS_CPU_EXCLUSIVE
, &cs
->flags
);
96 static inline int is_mem_exclusive(const struct cpuset
*cs
)
98 return !!test_bit(CS_MEM_EXCLUSIVE
, &cs
->flags
);
101 static inline int is_removed(const struct cpuset
*cs
)
103 return !!test_bit(CS_REMOVED
, &cs
->flags
);
106 static inline int notify_on_release(const struct cpuset
*cs
)
108 return !!test_bit(CS_NOTIFY_ON_RELEASE
, &cs
->flags
);
112 * Increment this atomic integer everytime any cpuset changes its
113 * mems_allowed value. Users of cpusets can track this generation
114 * number, and avoid having to lock and reload mems_allowed unless
115 * the cpuset they're using changes generation.
117 * A single, global generation is needed because attach_task() could
118 * reattach a task to a different cpuset, which must not have its
119 * generation numbers aliased with those of that tasks previous cpuset.
121 * Generations are needed for mems_allowed because one task cannot
122 * modify anothers memory placement. So we must enable every task,
123 * on every visit to __alloc_pages(), to efficiently check whether
124 * its current->cpuset->mems_allowed has changed, requiring an update
125 * of its current->mems_allowed.
127 static atomic_t cpuset_mems_generation
= ATOMIC_INIT(1);
129 static struct cpuset top_cpuset
= {
130 .flags
= ((1 << CS_CPU_EXCLUSIVE
) | (1 << CS_MEM_EXCLUSIVE
)),
131 .cpus_allowed
= CPU_MASK_ALL
,
132 .mems_allowed
= NODE_MASK_ALL
,
133 .count
= ATOMIC_INIT(0),
134 .sibling
= LIST_HEAD_INIT(top_cpuset
.sibling
),
135 .children
= LIST_HEAD_INIT(top_cpuset
.children
),
138 .mems_generation
= 0,
141 static struct vfsmount
*cpuset_mount
;
142 static struct super_block
*cpuset_sb
= NULL
;
145 * cpuset_sem should be held by anyone who is depending on the children
146 * or sibling lists of any cpuset, or performing non-atomic operations
147 * on the flags or *_allowed values of a cpuset, such as raising the
148 * CS_REMOVED flag bit iff it is not already raised, or reading and
149 * conditionally modifying the *_allowed values. One kernel global
150 * cpuset semaphore should be sufficient - these things don't change
153 * The code that modifies cpusets holds cpuset_sem across the entire
154 * operation, from cpuset_common_file_write() down, single threading
155 * all cpuset modifications (except for counter manipulations from
156 * fork and exit) across the system. This presumes that cpuset
157 * modifications are rare - better kept simple and safe, even if slow.
159 * The code that reads cpusets, such as in cpuset_common_file_read()
160 * and below, only holds cpuset_sem across small pieces of code, such
161 * as when reading out possibly multi-word cpumasks and nodemasks, as
162 * the risks are less, and the desire for performance a little greater.
163 * The proc_cpuset_show() routine needs to hold cpuset_sem to insure
164 * that no cs->dentry is NULL, as it walks up the cpuset tree to root.
166 * The hooks from fork and exit, cpuset_fork() and cpuset_exit(), don't
167 * (usually) grab cpuset_sem. These are the two most performance
168 * critical pieces of code here. The exception occurs on exit(),
169 * when a task in a notify_on_release cpuset exits. Then cpuset_sem
170 * is taken, and if the cpuset count is zero, a usermode call made
171 * to /sbin/cpuset_release_agent with the name of the cpuset (path
172 * relative to the root of cpuset file system) as the argument.
174 * A cpuset can only be deleted if both its 'count' of using tasks is
175 * zero, and its list of 'children' cpusets is empty. Since all tasks
176 * in the system use _some_ cpuset, and since there is always at least
177 * one task in the system (init, pid == 1), therefore, top_cpuset
178 * always has either children cpusets and/or using tasks. So no need
179 * for any special hack to ensure that top_cpuset cannot be deleted.
182 static DECLARE_MUTEX(cpuset_sem
);
185 * A couple of forward declarations required, due to cyclic reference loop:
186 * cpuset_mkdir -> cpuset_create -> cpuset_populate_dir -> cpuset_add_file
187 * -> cpuset_create_file -> cpuset_dir_inode_operations -> cpuset_mkdir.
190 static int cpuset_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
);
191 static int cpuset_rmdir(struct inode
*unused_dir
, struct dentry
*dentry
);
193 static struct backing_dev_info cpuset_backing_dev_info
= {
194 .ra_pages
= 0, /* No readahead */
195 .capabilities
= BDI_CAP_NO_ACCT_DIRTY
| BDI_CAP_NO_WRITEBACK
,
198 static struct inode
*cpuset_new_inode(mode_t mode
)
200 struct inode
*inode
= new_inode(cpuset_sb
);
203 inode
->i_mode
= mode
;
204 inode
->i_uid
= current
->fsuid
;
205 inode
->i_gid
= current
->fsgid
;
206 inode
->i_blksize
= PAGE_CACHE_SIZE
;
208 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
209 inode
->i_mapping
->backing_dev_info
= &cpuset_backing_dev_info
;
214 static void cpuset_diput(struct dentry
*dentry
, struct inode
*inode
)
216 /* is dentry a directory ? if so, kfree() associated cpuset */
217 if (S_ISDIR(inode
->i_mode
)) {
218 struct cpuset
*cs
= dentry
->d_fsdata
;
219 BUG_ON(!(is_removed(cs
)));
225 static struct dentry_operations cpuset_dops
= {
226 .d_iput
= cpuset_diput
,
229 static struct dentry
*cpuset_get_dentry(struct dentry
*parent
, const char *name
)
231 struct dentry
*d
= lookup_one_len(name
, parent
, strlen(name
));
233 d
->d_op
= &cpuset_dops
;
237 static void remove_dir(struct dentry
*d
)
239 struct dentry
*parent
= dget(d
->d_parent
);
242 simple_rmdir(parent
->d_inode
, d
);
247 * NOTE : the dentry must have been dget()'ed
249 static void cpuset_d_remove_dir(struct dentry
*dentry
)
251 struct list_head
*node
;
253 spin_lock(&dcache_lock
);
254 node
= dentry
->d_subdirs
.next
;
255 while (node
!= &dentry
->d_subdirs
) {
256 struct dentry
*d
= list_entry(node
, struct dentry
, d_child
);
260 spin_unlock(&dcache_lock
);
262 simple_unlink(dentry
->d_inode
, d
);
264 spin_lock(&dcache_lock
);
266 node
= dentry
->d_subdirs
.next
;
268 list_del_init(&dentry
->d_child
);
269 spin_unlock(&dcache_lock
);
273 static struct super_operations cpuset_ops
= {
274 .statfs
= simple_statfs
,
275 .drop_inode
= generic_delete_inode
,
278 static int cpuset_fill_super(struct super_block
*sb
, void *unused_data
,
284 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
285 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
286 sb
->s_magic
= CPUSET_SUPER_MAGIC
;
287 sb
->s_op
= &cpuset_ops
;
290 inode
= cpuset_new_inode(S_IFDIR
| S_IRUGO
| S_IXUGO
| S_IWUSR
);
292 inode
->i_op
= &simple_dir_inode_operations
;
293 inode
->i_fop
= &simple_dir_operations
;
294 /* directories start off with i_nlink == 2 (for "." entry) */
300 root
= d_alloc_root(inode
);
309 static struct super_block
*cpuset_get_sb(struct file_system_type
*fs_type
,
310 int flags
, const char *unused_dev_name
,
313 return get_sb_single(fs_type
, flags
, data
, cpuset_fill_super
);
316 static struct file_system_type cpuset_fs_type
= {
318 .get_sb
= cpuset_get_sb
,
319 .kill_sb
= kill_litter_super
,
324 * The files in the cpuset filesystem mostly have a very simple read/write
325 * handling, some common function will take care of it. Nevertheless some cases
326 * (read tasks) are special and therefore I define this structure for every
330 * When reading/writing to a file:
331 * - the cpuset to use in file->f_dentry->d_parent->d_fsdata
332 * - the 'cftype' of the file is file->f_dentry->d_fsdata
338 int (*open
) (struct inode
*inode
, struct file
*file
);
339 ssize_t (*read
) (struct file
*file
, char __user
*buf
, size_t nbytes
,
341 int (*write
) (struct file
*file
, const char __user
*buf
, size_t nbytes
,
343 int (*release
) (struct inode
*inode
, struct file
*file
);
346 static inline struct cpuset
*__d_cs(struct dentry
*dentry
)
348 return dentry
->d_fsdata
;
351 static inline struct cftype
*__d_cft(struct dentry
*dentry
)
353 return dentry
->d_fsdata
;
357 * Call with cpuset_sem held. Writes path of cpuset into buf.
358 * Returns 0 on success, -errno on error.
361 static int cpuset_path(const struct cpuset
*cs
, char *buf
, int buflen
)
365 start
= buf
+ buflen
;
369 int len
= cs
->dentry
->d_name
.len
;
370 if ((start
-= len
) < buf
)
371 return -ENAMETOOLONG
;
372 memcpy(start
, cs
->dentry
->d_name
.name
, len
);
379 return -ENAMETOOLONG
;
382 memmove(buf
, start
, buf
+ buflen
- start
);
387 * Notify userspace when a cpuset is released, by running
388 * /sbin/cpuset_release_agent with the name of the cpuset (path
389 * relative to the root of cpuset file system) as the argument.
391 * Most likely, this user command will try to rmdir this cpuset.
393 * This races with the possibility that some other task will be
394 * attached to this cpuset before it is removed, or that some other
395 * user task will 'mkdir' a child cpuset of this cpuset. That's ok.
396 * The presumed 'rmdir' will fail quietly if this cpuset is no longer
397 * unused, and this cpuset will be reprieved from its death sentence,
398 * to continue to serve a useful existence. Next time it's released,
399 * we will get notified again, if it still has 'notify_on_release' set.
401 * The final arg to call_usermodehelper() is 0, which means don't
402 * wait. The separate /sbin/cpuset_release_agent task is forked by
403 * call_usermodehelper(), then control in this thread returns here,
404 * without waiting for the release agent task. We don't bother to
405 * wait because the caller of this routine has no use for the exit
406 * status of the /sbin/cpuset_release_agent task, so no sense holding
407 * our caller up for that.
409 * The simple act of forking that task might require more memory,
410 * which might need cpuset_sem. So this routine must be called while
411 * cpuset_sem is not held, to avoid a possible deadlock. See also
412 * comments for check_for_release(), below.
415 static void cpuset_release_agent(const char *pathbuf
)
417 char *argv
[3], *envp
[3];
424 argv
[i
++] = "/sbin/cpuset_release_agent";
425 argv
[i
++] = (char *)pathbuf
;
429 /* minimal command environment */
430 envp
[i
++] = "HOME=/";
431 envp
[i
++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
434 call_usermodehelper(argv
[0], argv
, envp
, 0);
439 * Either cs->count of using tasks transitioned to zero, or the
440 * cs->children list of child cpusets just became empty. If this
441 * cs is notify_on_release() and now both the user count is zero and
442 * the list of children is empty, prepare cpuset path in a kmalloc'd
443 * buffer, to be returned via ppathbuf, so that the caller can invoke
444 * cpuset_release_agent() with it later on, once cpuset_sem is dropped.
445 * Call here with cpuset_sem held.
447 * This check_for_release() routine is responsible for kmalloc'ing
448 * pathbuf. The above cpuset_release_agent() is responsible for
449 * kfree'ing pathbuf. The caller of these routines is responsible
450 * for providing a pathbuf pointer, initialized to NULL, then
451 * calling check_for_release() with cpuset_sem held and the address
452 * of the pathbuf pointer, then dropping cpuset_sem, then calling
453 * cpuset_release_agent() with pathbuf, as set by check_for_release().
456 static void check_for_release(struct cpuset
*cs
, char **ppathbuf
)
458 if (notify_on_release(cs
) && atomic_read(&cs
->count
) == 0 &&
459 list_empty(&cs
->children
)) {
462 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
465 if (cpuset_path(cs
, buf
, PAGE_SIZE
) < 0)
473 * Return in *pmask the portion of a cpusets's cpus_allowed that
474 * are online. If none are online, walk up the cpuset hierarchy
475 * until we find one that does have some online cpus. If we get
476 * all the way to the top and still haven't found any online cpus,
477 * return cpu_online_map. Or if passed a NULL cs from an exit'ing
478 * task, return cpu_online_map.
480 * One way or another, we guarantee to return some non-empty subset
483 * Call with cpuset_sem held.
486 static void guarantee_online_cpus(const struct cpuset
*cs
, cpumask_t
*pmask
)
488 while (cs
&& !cpus_intersects(cs
->cpus_allowed
, cpu_online_map
))
491 cpus_and(*pmask
, cs
->cpus_allowed
, cpu_online_map
);
493 *pmask
= cpu_online_map
;
494 BUG_ON(!cpus_intersects(*pmask
, cpu_online_map
));
498 * Return in *pmask the portion of a cpusets's mems_allowed that
499 * are online. If none are online, walk up the cpuset hierarchy
500 * until we find one that does have some online mems. If we get
501 * all the way to the top and still haven't found any online mems,
502 * return node_online_map.
504 * One way or another, we guarantee to return some non-empty subset
505 * of node_online_map.
507 * Call with cpuset_sem held.
510 static void guarantee_online_mems(const struct cpuset
*cs
, nodemask_t
*pmask
)
512 while (cs
&& !nodes_intersects(cs
->mems_allowed
, node_online_map
))
515 nodes_and(*pmask
, cs
->mems_allowed
, node_online_map
);
517 *pmask
= node_online_map
;
518 BUG_ON(!nodes_intersects(*pmask
, node_online_map
));
522 * Refresh current tasks mems_allowed and mems_generation from
523 * current tasks cpuset. Call with cpuset_sem held.
525 * Be sure to call refresh_mems() on any cpuset operation which
526 * (1) holds cpuset_sem, and (2) might possibly alloc memory.
527 * Call after obtaining cpuset_sem lock, before any possible
528 * allocation. Otherwise one risks trying to allocate memory
529 * while the task cpuset_mems_generation is not the same as
530 * the mems_generation in its cpuset, which would deadlock on
531 * cpuset_sem in cpuset_update_current_mems_allowed().
533 * Since we hold cpuset_sem, once refresh_mems() is called, the
534 * test (current->cpuset_mems_generation != cs->mems_generation)
535 * in cpuset_update_current_mems_allowed() will remain false,
536 * until we drop cpuset_sem. Anyone else who would change our
537 * cpusets mems_generation needs to lock cpuset_sem first.
540 static void refresh_mems(void)
542 struct cpuset
*cs
= current
->cpuset
;
544 if (current
->cpuset_mems_generation
!= cs
->mems_generation
) {
545 guarantee_online_mems(cs
, ¤t
->mems_allowed
);
546 current
->cpuset_mems_generation
= cs
->mems_generation
;
551 * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q?
553 * One cpuset is a subset of another if all its allowed CPUs and
554 * Memory Nodes are a subset of the other, and its exclusive flags
555 * are only set if the other's are set.
558 static int is_cpuset_subset(const struct cpuset
*p
, const struct cpuset
*q
)
560 return cpus_subset(p
->cpus_allowed
, q
->cpus_allowed
) &&
561 nodes_subset(p
->mems_allowed
, q
->mems_allowed
) &&
562 is_cpu_exclusive(p
) <= is_cpu_exclusive(q
) &&
563 is_mem_exclusive(p
) <= is_mem_exclusive(q
);
567 * validate_change() - Used to validate that any proposed cpuset change
568 * follows the structural rules for cpusets.
570 * If we replaced the flag and mask values of the current cpuset
571 * (cur) with those values in the trial cpuset (trial), would
572 * our various subset and exclusive rules still be valid? Presumes
575 * 'cur' is the address of an actual, in-use cpuset. Operations
576 * such as list traversal that depend on the actual address of the
577 * cpuset in the list must use cur below, not trial.
579 * 'trial' is the address of bulk structure copy of cur, with
580 * perhaps one or more of the fields cpus_allowed, mems_allowed,
581 * or flags changed to new, trial values.
583 * Return 0 if valid, -errno if not.
586 static int validate_change(const struct cpuset
*cur
, const struct cpuset
*trial
)
588 struct cpuset
*c
, *par
;
590 /* Each of our child cpusets must be a subset of us */
591 list_for_each_entry(c
, &cur
->children
, sibling
) {
592 if (!is_cpuset_subset(c
, trial
))
596 /* Remaining checks don't apply to root cpuset */
597 if ((par
= cur
->parent
) == NULL
)
600 /* We must be a subset of our parent cpuset */
601 if (!is_cpuset_subset(trial
, par
))
604 /* If either I or some sibling (!= me) is exclusive, we can't overlap */
605 list_for_each_entry(c
, &par
->children
, sibling
) {
606 if ((is_cpu_exclusive(trial
) || is_cpu_exclusive(c
)) &&
608 cpus_intersects(trial
->cpus_allowed
, c
->cpus_allowed
))
610 if ((is_mem_exclusive(trial
) || is_mem_exclusive(c
)) &&
612 nodes_intersects(trial
->mems_allowed
, c
->mems_allowed
))
620 * For a given cpuset cur, partition the system as follows
621 * a. All cpus in the parent cpuset's cpus_allowed that are not part of any
622 * exclusive child cpusets
623 * b. All cpus in the current cpuset's cpus_allowed that are not part of any
624 * exclusive child cpusets
625 * Build these two partitions by calling partition_sched_domains
627 * Call with cpuset_sem held. May nest a call to the
628 * lock_cpu_hotplug()/unlock_cpu_hotplug() pair.
630 static void update_cpu_domains(struct cpuset
*cur
)
632 struct cpuset
*c
, *par
= cur
->parent
;
633 cpumask_t pspan
, cspan
;
635 if (par
== NULL
|| cpus_empty(cur
->cpus_allowed
))
639 * Hack to avoid 2.6.13 partial node dynamic sched domain bug.
640 * Require the 'cpu_exclusive' cpuset to include all (or none)
641 * of the CPUs on each node, or return w/o changing sched domains.
642 * Remove this hack when dynamic sched domains fixed.
647 for_each_cpu_mask(i
, cur
->cpus_allowed
) {
648 for_each_cpu_mask(j
, node_to_cpumask(cpu_to_node(i
))) {
649 if (!cpu_isset(j
, cur
->cpus_allowed
))
656 * Get all cpus from parent's cpus_allowed not part of exclusive
659 pspan
= par
->cpus_allowed
;
660 list_for_each_entry(c
, &par
->children
, sibling
) {
661 if (is_cpu_exclusive(c
))
662 cpus_andnot(pspan
, pspan
, c
->cpus_allowed
);
664 if (is_removed(cur
) || !is_cpu_exclusive(cur
)) {
665 cpus_or(pspan
, pspan
, cur
->cpus_allowed
);
666 if (cpus_equal(pspan
, cur
->cpus_allowed
))
668 cspan
= CPU_MASK_NONE
;
670 if (cpus_empty(pspan
))
672 cspan
= cur
->cpus_allowed
;
674 * Get all cpus from current cpuset's cpus_allowed not part
675 * of exclusive children
677 list_for_each_entry(c
, &cur
->children
, sibling
) {
678 if (is_cpu_exclusive(c
))
679 cpus_andnot(cspan
, cspan
, c
->cpus_allowed
);
684 partition_sched_domains(&pspan
, &cspan
);
685 unlock_cpu_hotplug();
688 static int update_cpumask(struct cpuset
*cs
, char *buf
)
690 struct cpuset trialcs
;
691 int retval
, cpus_unchanged
;
694 retval
= cpulist_parse(buf
, trialcs
.cpus_allowed
);
697 cpus_and(trialcs
.cpus_allowed
, trialcs
.cpus_allowed
, cpu_online_map
);
698 if (cpus_empty(trialcs
.cpus_allowed
))
700 retval
= validate_change(cs
, &trialcs
);
703 cpus_unchanged
= cpus_equal(cs
->cpus_allowed
, trialcs
.cpus_allowed
);
704 cs
->cpus_allowed
= trialcs
.cpus_allowed
;
705 if (is_cpu_exclusive(cs
) && !cpus_unchanged
)
706 update_cpu_domains(cs
);
710 static int update_nodemask(struct cpuset
*cs
, char *buf
)
712 struct cpuset trialcs
;
716 retval
= nodelist_parse(buf
, trialcs
.mems_allowed
);
719 nodes_and(trialcs
.mems_allowed
, trialcs
.mems_allowed
, node_online_map
);
720 if (nodes_empty(trialcs
.mems_allowed
))
722 retval
= validate_change(cs
, &trialcs
);
724 cs
->mems_allowed
= trialcs
.mems_allowed
;
725 atomic_inc(&cpuset_mems_generation
);
726 cs
->mems_generation
= atomic_read(&cpuset_mems_generation
);
732 * update_flag - read a 0 or a 1 in a file and update associated flag
733 * bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE,
734 * CS_NOTIFY_ON_RELEASE)
735 * cs: the cpuset to update
736 * buf: the buffer where we read the 0 or 1
739 static int update_flag(cpuset_flagbits_t bit
, struct cpuset
*cs
, char *buf
)
742 struct cpuset trialcs
;
743 int err
, cpu_exclusive_changed
;
745 turning_on
= (simple_strtoul(buf
, NULL
, 10) != 0);
749 set_bit(bit
, &trialcs
.flags
);
751 clear_bit(bit
, &trialcs
.flags
);
753 err
= validate_change(cs
, &trialcs
);
756 cpu_exclusive_changed
=
757 (is_cpu_exclusive(cs
) != is_cpu_exclusive(&trialcs
));
759 set_bit(bit
, &cs
->flags
);
761 clear_bit(bit
, &cs
->flags
);
763 if (cpu_exclusive_changed
)
764 update_cpu_domains(cs
);
768 static int attach_task(struct cpuset
*cs
, char *pidbuf
, char **ppathbuf
)
771 struct task_struct
*tsk
;
772 struct cpuset
*oldcs
;
775 if (sscanf(pidbuf
, "%d", &pid
) != 1)
777 if (cpus_empty(cs
->cpus_allowed
) || nodes_empty(cs
->mems_allowed
))
781 read_lock(&tasklist_lock
);
783 tsk
= find_task_by_pid(pid
);
785 read_unlock(&tasklist_lock
);
789 get_task_struct(tsk
);
790 read_unlock(&tasklist_lock
);
792 if ((current
->euid
) && (current
->euid
!= tsk
->uid
)
793 && (current
->euid
!= tsk
->suid
)) {
794 put_task_struct(tsk
);
799 get_task_struct(tsk
);
806 put_task_struct(tsk
);
809 atomic_inc(&cs
->count
);
813 guarantee_online_cpus(cs
, &cpus
);
814 set_cpus_allowed(tsk
, cpus
);
816 put_task_struct(tsk
);
817 if (atomic_dec_and_test(&oldcs
->count
))
818 check_for_release(oldcs
, ppathbuf
);
822 /* The various types of files and directories in a cpuset file system */
831 FILE_NOTIFY_ON_RELEASE
,
835 static ssize_t
cpuset_common_file_write(struct file
*file
, const char __user
*userbuf
,
836 size_t nbytes
, loff_t
*unused_ppos
)
838 struct cpuset
*cs
= __d_cs(file
->f_dentry
->d_parent
);
839 struct cftype
*cft
= __d_cft(file
->f_dentry
);
840 cpuset_filetype_t type
= cft
->private;
842 char *pathbuf
= NULL
;
845 /* Crude upper limit on largest legitimate cpulist user might write. */
846 if (nbytes
> 100 + 6 * NR_CPUS
)
849 /* +1 for nul-terminator */
850 if ((buffer
= kmalloc(nbytes
+ 1, GFP_KERNEL
)) == 0)
853 if (copy_from_user(buffer
, userbuf
, nbytes
)) {
857 buffer
[nbytes
] = 0; /* nul-terminate */
861 if (is_removed(cs
)) {
868 retval
= update_cpumask(cs
, buffer
);
871 retval
= update_nodemask(cs
, buffer
);
873 case FILE_CPU_EXCLUSIVE
:
874 retval
= update_flag(CS_CPU_EXCLUSIVE
, cs
, buffer
);
876 case FILE_MEM_EXCLUSIVE
:
877 retval
= update_flag(CS_MEM_EXCLUSIVE
, cs
, buffer
);
879 case FILE_NOTIFY_ON_RELEASE
:
880 retval
= update_flag(CS_NOTIFY_ON_RELEASE
, cs
, buffer
);
883 retval
= attach_task(cs
, buffer
, &pathbuf
);
894 cpuset_release_agent(pathbuf
);
900 static ssize_t
cpuset_file_write(struct file
*file
, const char __user
*buf
,
901 size_t nbytes
, loff_t
*ppos
)
904 struct cftype
*cft
= __d_cft(file
->f_dentry
);
908 /* special function ? */
910 retval
= cft
->write(file
, buf
, nbytes
, ppos
);
912 retval
= cpuset_common_file_write(file
, buf
, nbytes
, ppos
);
918 * These ascii lists should be read in a single call, by using a user
919 * buffer large enough to hold the entire map. If read in smaller
920 * chunks, there is no guarantee of atomicity. Since the display format
921 * used, list of ranges of sequential numbers, is variable length,
922 * and since these maps can change value dynamically, one could read
923 * gibberish by doing partial reads while a list was changing.
924 * A single large read to a buffer that crosses a page boundary is
925 * ok, because the result being copied to user land is not recomputed
926 * across a page fault.
929 static int cpuset_sprintf_cpulist(char *page
, struct cpuset
*cs
)
934 mask
= cs
->cpus_allowed
;
937 return cpulist_scnprintf(page
, PAGE_SIZE
, mask
);
940 static int cpuset_sprintf_memlist(char *page
, struct cpuset
*cs
)
945 mask
= cs
->mems_allowed
;
948 return nodelist_scnprintf(page
, PAGE_SIZE
, mask
);
951 static ssize_t
cpuset_common_file_read(struct file
*file
, char __user
*buf
,
952 size_t nbytes
, loff_t
*ppos
)
954 struct cftype
*cft
= __d_cft(file
->f_dentry
);
955 struct cpuset
*cs
= __d_cs(file
->f_dentry
->d_parent
);
956 cpuset_filetype_t type
= cft
->private;
963 if (!(page
= (char *)__get_free_page(GFP_KERNEL
)))
970 s
+= cpuset_sprintf_cpulist(s
, cs
);
973 s
+= cpuset_sprintf_memlist(s
, cs
);
975 case FILE_CPU_EXCLUSIVE
:
976 *s
++ = is_cpu_exclusive(cs
) ? '1' : '0';
978 case FILE_MEM_EXCLUSIVE
:
979 *s
++ = is_mem_exclusive(cs
) ? '1' : '0';
981 case FILE_NOTIFY_ON_RELEASE
:
982 *s
++ = notify_on_release(cs
) ? '1' : '0';
991 start
= page
+ *ppos
;
993 retval
= n
- copy_to_user(buf
, start
, min(n
, nbytes
));
996 free_page((unsigned long)page
);
1000 static ssize_t
cpuset_file_read(struct file
*file
, char __user
*buf
, size_t nbytes
,
1004 struct cftype
*cft
= __d_cft(file
->f_dentry
);
1008 /* special function ? */
1010 retval
= cft
->read(file
, buf
, nbytes
, ppos
);
1012 retval
= cpuset_common_file_read(file
, buf
, nbytes
, ppos
);
1017 static int cpuset_file_open(struct inode
*inode
, struct file
*file
)
1022 err
= generic_file_open(inode
, file
);
1026 cft
= __d_cft(file
->f_dentry
);
1030 err
= cft
->open(inode
, file
);
1037 static int cpuset_file_release(struct inode
*inode
, struct file
*file
)
1039 struct cftype
*cft
= __d_cft(file
->f_dentry
);
1041 return cft
->release(inode
, file
);
1045 static struct file_operations cpuset_file_operations
= {
1046 .read
= cpuset_file_read
,
1047 .write
= cpuset_file_write
,
1048 .llseek
= generic_file_llseek
,
1049 .open
= cpuset_file_open
,
1050 .release
= cpuset_file_release
,
1053 static struct inode_operations cpuset_dir_inode_operations
= {
1054 .lookup
= simple_lookup
,
1055 .mkdir
= cpuset_mkdir
,
1056 .rmdir
= cpuset_rmdir
,
1059 static int cpuset_create_file(struct dentry
*dentry
, int mode
)
1061 struct inode
*inode
;
1065 if (dentry
->d_inode
)
1068 inode
= cpuset_new_inode(mode
);
1072 if (S_ISDIR(mode
)) {
1073 inode
->i_op
= &cpuset_dir_inode_operations
;
1074 inode
->i_fop
= &simple_dir_operations
;
1076 /* start off with i_nlink == 2 (for "." entry) */
1078 } else if (S_ISREG(mode
)) {
1080 inode
->i_fop
= &cpuset_file_operations
;
1083 d_instantiate(dentry
, inode
);
1084 dget(dentry
); /* Extra count - pin the dentry in core */
1089 * cpuset_create_dir - create a directory for an object.
1090 * cs: the cpuset we create the directory for.
1091 * It must have a valid ->parent field
1092 * And we are going to fill its ->dentry field.
1093 * name: The name to give to the cpuset directory. Will be copied.
1094 * mode: mode to set on new directory.
1097 static int cpuset_create_dir(struct cpuset
*cs
, const char *name
, int mode
)
1099 struct dentry
*dentry
= NULL
;
1100 struct dentry
*parent
;
1103 parent
= cs
->parent
->dentry
;
1104 dentry
= cpuset_get_dentry(parent
, name
);
1106 return PTR_ERR(dentry
);
1107 error
= cpuset_create_file(dentry
, S_IFDIR
| mode
);
1109 dentry
->d_fsdata
= cs
;
1110 parent
->d_inode
->i_nlink
++;
1111 cs
->dentry
= dentry
;
1118 static int cpuset_add_file(struct dentry
*dir
, const struct cftype
*cft
)
1120 struct dentry
*dentry
;
1123 down(&dir
->d_inode
->i_sem
);
1124 dentry
= cpuset_get_dentry(dir
, cft
->name
);
1125 if (!IS_ERR(dentry
)) {
1126 error
= cpuset_create_file(dentry
, 0644 | S_IFREG
);
1128 dentry
->d_fsdata
= (void *)cft
;
1131 error
= PTR_ERR(dentry
);
1132 up(&dir
->d_inode
->i_sem
);
1137 * Stuff for reading the 'tasks' file.
1139 * Reading this file can return large amounts of data if a cpuset has
1140 * *lots* of attached tasks. So it may need several calls to read(),
1141 * but we cannot guarantee that the information we produce is correct
1142 * unless we produce it entirely atomically.
1144 * Upon tasks file open(), a struct ctr_struct is allocated, that
1145 * will have a pointer to an array (also allocated here). The struct
1146 * ctr_struct * is stored in file->private_data. Its resources will
1147 * be freed by release() when the file is closed. The array is used
1148 * to sprintf the PIDs and then used by read().
1151 /* cpusets_tasks_read array */
1159 * Load into 'pidarray' up to 'npids' of the tasks using cpuset 'cs'.
1160 * Return actual number of pids loaded.
1162 static inline int pid_array_load(pid_t
*pidarray
, int npids
, struct cpuset
*cs
)
1165 struct task_struct
*g
, *p
;
1167 read_lock(&tasklist_lock
);
1169 do_each_thread(g
, p
) {
1170 if (p
->cpuset
== cs
) {
1171 pidarray
[n
++] = p
->pid
;
1172 if (unlikely(n
== npids
))
1175 } while_each_thread(g
, p
);
1178 read_unlock(&tasklist_lock
);
1182 static int cmppid(const void *a
, const void *b
)
1184 return *(pid_t
*)a
- *(pid_t
*)b
;
1188 * Convert array 'a' of 'npids' pid_t's to a string of newline separated
1189 * decimal pids in 'buf'. Don't write more than 'sz' chars, but return
1190 * count 'cnt' of how many chars would be written if buf were large enough.
1192 static int pid_array_to_buf(char *buf
, int sz
, pid_t
*a
, int npids
)
1197 for (i
= 0; i
< npids
; i
++)
1198 cnt
+= snprintf(buf
+ cnt
, max(sz
- cnt
, 0), "%d\n", a
[i
]);
1202 static int cpuset_tasks_open(struct inode
*unused
, struct file
*file
)
1204 struct cpuset
*cs
= __d_cs(file
->f_dentry
->d_parent
);
1205 struct ctr_struct
*ctr
;
1210 if (!(file
->f_mode
& FMODE_READ
))
1213 ctr
= kmalloc(sizeof(*ctr
), GFP_KERNEL
);
1218 * If cpuset gets more users after we read count, we won't have
1219 * enough space - tough. This race is indistinguishable to the
1220 * caller from the case that the additional cpuset users didn't
1221 * show up until sometime later on.
1223 npids
= atomic_read(&cs
->count
);
1224 pidarray
= kmalloc(npids
* sizeof(pid_t
), GFP_KERNEL
);
1228 npids
= pid_array_load(pidarray
, npids
, cs
);
1229 sort(pidarray
, npids
, sizeof(pid_t
), cmppid
, NULL
);
1231 /* Call pid_array_to_buf() twice, first just to get bufsz */
1232 ctr
->bufsz
= pid_array_to_buf(&c
, sizeof(c
), pidarray
, npids
) + 1;
1233 ctr
->buf
= kmalloc(ctr
->bufsz
, GFP_KERNEL
);
1236 ctr
->bufsz
= pid_array_to_buf(ctr
->buf
, ctr
->bufsz
, pidarray
, npids
);
1239 file
->private_data
= ctr
;
1250 static ssize_t
cpuset_tasks_read(struct file
*file
, char __user
*buf
,
1251 size_t nbytes
, loff_t
*ppos
)
1253 struct ctr_struct
*ctr
= file
->private_data
;
1255 if (*ppos
+ nbytes
> ctr
->bufsz
)
1256 nbytes
= ctr
->bufsz
- *ppos
;
1257 if (copy_to_user(buf
, ctr
->buf
+ *ppos
, nbytes
))
1263 static int cpuset_tasks_release(struct inode
*unused_inode
, struct file
*file
)
1265 struct ctr_struct
*ctr
;
1267 if (file
->f_mode
& FMODE_READ
) {
1268 ctr
= file
->private_data
;
1276 * for the common functions, 'private' gives the type of file
1279 static struct cftype cft_tasks
= {
1281 .open
= cpuset_tasks_open
,
1282 .read
= cpuset_tasks_read
,
1283 .release
= cpuset_tasks_release
,
1284 .private = FILE_TASKLIST
,
1287 static struct cftype cft_cpus
= {
1289 .private = FILE_CPULIST
,
1292 static struct cftype cft_mems
= {
1294 .private = FILE_MEMLIST
,
1297 static struct cftype cft_cpu_exclusive
= {
1298 .name
= "cpu_exclusive",
1299 .private = FILE_CPU_EXCLUSIVE
,
1302 static struct cftype cft_mem_exclusive
= {
1303 .name
= "mem_exclusive",
1304 .private = FILE_MEM_EXCLUSIVE
,
1307 static struct cftype cft_notify_on_release
= {
1308 .name
= "notify_on_release",
1309 .private = FILE_NOTIFY_ON_RELEASE
,
1312 static int cpuset_populate_dir(struct dentry
*cs_dentry
)
1316 if ((err
= cpuset_add_file(cs_dentry
, &cft_cpus
)) < 0)
1318 if ((err
= cpuset_add_file(cs_dentry
, &cft_mems
)) < 0)
1320 if ((err
= cpuset_add_file(cs_dentry
, &cft_cpu_exclusive
)) < 0)
1322 if ((err
= cpuset_add_file(cs_dentry
, &cft_mem_exclusive
)) < 0)
1324 if ((err
= cpuset_add_file(cs_dentry
, &cft_notify_on_release
)) < 0)
1326 if ((err
= cpuset_add_file(cs_dentry
, &cft_tasks
)) < 0)
1332 * cpuset_create - create a cpuset
1333 * parent: cpuset that will be parent of the new cpuset.
1334 * name: name of the new cpuset. Will be strcpy'ed.
1335 * mode: mode to set on new inode
1337 * Must be called with the semaphore on the parent inode held
1340 static long cpuset_create(struct cpuset
*parent
, const char *name
, int mode
)
1345 cs
= kmalloc(sizeof(*cs
), GFP_KERNEL
);
1352 if (notify_on_release(parent
))
1353 set_bit(CS_NOTIFY_ON_RELEASE
, &cs
->flags
);
1354 cs
->cpus_allowed
= CPU_MASK_NONE
;
1355 cs
->mems_allowed
= NODE_MASK_NONE
;
1356 atomic_set(&cs
->count
, 0);
1357 INIT_LIST_HEAD(&cs
->sibling
);
1358 INIT_LIST_HEAD(&cs
->children
);
1359 atomic_inc(&cpuset_mems_generation
);
1360 cs
->mems_generation
= atomic_read(&cpuset_mems_generation
);
1362 cs
->parent
= parent
;
1364 list_add(&cs
->sibling
, &cs
->parent
->children
);
1366 err
= cpuset_create_dir(cs
, name
, mode
);
1371 * Release cpuset_sem before cpuset_populate_dir() because it
1372 * will down() this new directory's i_sem and if we race with
1373 * another mkdir, we might deadlock.
1377 err
= cpuset_populate_dir(cs
->dentry
);
1378 /* If err < 0, we have a half-filled directory - oh well ;) */
1381 list_del(&cs
->sibling
);
1387 static int cpuset_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
1389 struct cpuset
*c_parent
= dentry
->d_parent
->d_fsdata
;
1391 /* the vfs holds inode->i_sem already */
1392 return cpuset_create(c_parent
, dentry
->d_name
.name
, mode
| S_IFDIR
);
1395 static int cpuset_rmdir(struct inode
*unused_dir
, struct dentry
*dentry
)
1397 struct cpuset
*cs
= dentry
->d_fsdata
;
1399 struct cpuset
*parent
;
1400 char *pathbuf
= NULL
;
1402 /* the vfs holds both inode->i_sem already */
1406 if (atomic_read(&cs
->count
) > 0) {
1410 if (!list_empty(&cs
->children
)) {
1414 parent
= cs
->parent
;
1415 set_bit(CS_REMOVED
, &cs
->flags
);
1416 if (is_cpu_exclusive(cs
))
1417 update_cpu_domains(cs
);
1418 list_del(&cs
->sibling
); /* delete my sibling from parent->children */
1419 if (list_empty(&parent
->children
))
1420 check_for_release(parent
, &pathbuf
);
1421 spin_lock(&cs
->dentry
->d_lock
);
1422 d
= dget(cs
->dentry
);
1424 spin_unlock(&d
->d_lock
);
1425 cpuset_d_remove_dir(d
);
1428 cpuset_release_agent(pathbuf
);
1433 * cpuset_init - initialize cpusets at system boot
1435 * Description: Initialize top_cpuset and the cpuset internal file system,
1438 int __init
cpuset_init(void)
1440 struct dentry
*root
;
1443 top_cpuset
.cpus_allowed
= CPU_MASK_ALL
;
1444 top_cpuset
.mems_allowed
= NODE_MASK_ALL
;
1446 atomic_inc(&cpuset_mems_generation
);
1447 top_cpuset
.mems_generation
= atomic_read(&cpuset_mems_generation
);
1449 init_task
.cpuset
= &top_cpuset
;
1451 err
= register_filesystem(&cpuset_fs_type
);
1454 cpuset_mount
= kern_mount(&cpuset_fs_type
);
1455 if (IS_ERR(cpuset_mount
)) {
1456 printk(KERN_ERR
"cpuset: could not mount!\n");
1457 err
= PTR_ERR(cpuset_mount
);
1458 cpuset_mount
= NULL
;
1461 root
= cpuset_mount
->mnt_sb
->s_root
;
1462 root
->d_fsdata
= &top_cpuset
;
1463 root
->d_inode
->i_nlink
++;
1464 top_cpuset
.dentry
= root
;
1465 root
->d_inode
->i_op
= &cpuset_dir_inode_operations
;
1466 err
= cpuset_populate_dir(root
);
1472 * cpuset_init_smp - initialize cpus_allowed
1474 * Description: Finish top cpuset after cpu, node maps are initialized
1477 void __init
cpuset_init_smp(void)
1479 top_cpuset
.cpus_allowed
= cpu_online_map
;
1480 top_cpuset
.mems_allowed
= node_online_map
;
1484 * cpuset_fork - attach newly forked task to its parents cpuset.
1485 * @tsk: pointer to task_struct of forking parent process.
1487 * Description: By default, on fork, a task inherits its
1488 * parent's cpuset. The pointer to the shared cpuset is
1489 * automatically copied in fork.c by dup_task_struct().
1490 * This cpuset_fork() routine need only increment the usage
1491 * counter in that cpuset.
1494 void cpuset_fork(struct task_struct
*tsk
)
1496 atomic_inc(&tsk
->cpuset
->count
);
1500 * cpuset_exit - detach cpuset from exiting task
1501 * @tsk: pointer to task_struct of exiting process
1503 * Description: Detach cpuset from @tsk and release it.
1505 * Note that cpusets marked notify_on_release force every task
1506 * in them to take the global cpuset_sem semaphore when exiting.
1507 * This could impact scaling on very large systems. Be reluctant
1508 * to use notify_on_release cpusets where very high task exit
1509 * scaling is required on large systems.
1511 * Don't even think about derefencing 'cs' after the cpuset use
1512 * count goes to zero, except inside a critical section guarded
1513 * by the cpuset_sem semaphore. If you don't hold cpuset_sem,
1514 * then a zero cpuset use count is a license to any other task to
1515 * nuke the cpuset immediately.
1518 void cpuset_exit(struct task_struct
*tsk
)
1527 if (notify_on_release(cs
)) {
1528 char *pathbuf
= NULL
;
1531 if (atomic_dec_and_test(&cs
->count
))
1532 check_for_release(cs
, &pathbuf
);
1534 cpuset_release_agent(pathbuf
);
1536 atomic_dec(&cs
->count
);
1541 * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
1542 * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
1544 * Description: Returns the cpumask_t cpus_allowed of the cpuset
1545 * attached to the specified @tsk. Guaranteed to return some non-empty
1546 * subset of cpu_online_map, even if this means going outside the
1550 cpumask_t
cpuset_cpus_allowed(const struct task_struct
*tsk
)
1555 task_lock((struct task_struct
*)tsk
);
1556 guarantee_online_cpus(tsk
->cpuset
, &mask
);
1557 task_unlock((struct task_struct
*)tsk
);
1563 void cpuset_init_current_mems_allowed(void)
1565 current
->mems_allowed
= NODE_MASK_ALL
;
1569 * cpuset_update_current_mems_allowed - update mems parameters to new values
1571 * If the current tasks cpusets mems_allowed changed behind our backs,
1572 * update current->mems_allowed and mems_generation to the new value.
1573 * Do not call this routine if in_interrupt().
1576 void cpuset_update_current_mems_allowed(void)
1578 struct cpuset
*cs
= current
->cpuset
;
1581 return; /* task is exiting */
1582 if (current
->cpuset_mems_generation
!= cs
->mems_generation
) {
1590 * cpuset_restrict_to_mems_allowed - limit nodes to current mems_allowed
1591 * @nodes: pointer to a node bitmap that is and-ed with mems_allowed
1593 void cpuset_restrict_to_mems_allowed(unsigned long *nodes
)
1595 bitmap_and(nodes
, nodes
, nodes_addr(current
->mems_allowed
),
1600 * cpuset_zonelist_valid_mems_allowed - check zonelist vs. curremt mems_allowed
1601 * @zl: the zonelist to be checked
1603 * Are any of the nodes on zonelist zl allowed in current->mems_allowed?
1605 int cpuset_zonelist_valid_mems_allowed(struct zonelist
*zl
)
1609 for (i
= 0; zl
->zones
[i
]; i
++) {
1610 int nid
= zl
->zones
[i
]->zone_pgdat
->node_id
;
1612 if (node_isset(nid
, current
->mems_allowed
))
1619 * cpuset_zone_allowed - is zone z allowed in current->mems_allowed
1620 * @z: zone in question
1622 * Is zone z allowed in current->mems_allowed, or is
1623 * the CPU in interrupt context? (zone is always allowed in this case)
1625 int cpuset_zone_allowed(struct zone
*z
)
1627 return in_interrupt() ||
1628 node_isset(z
->zone_pgdat
->node_id
, current
->mems_allowed
);
1632 * proc_cpuset_show()
1633 * - Print tasks cpuset path into seq_file.
1634 * - Used for /proc/<pid>/cpuset.
1637 static int proc_cpuset_show(struct seq_file
*m
, void *v
)
1640 struct task_struct
*tsk
;
1644 buf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
1658 retval
= cpuset_path(cs
, buf
, PAGE_SIZE
);
1669 static int cpuset_open(struct inode
*inode
, struct file
*file
)
1671 struct task_struct
*tsk
= PROC_I(inode
)->task
;
1672 return single_open(file
, proc_cpuset_show
, tsk
);
1675 struct file_operations proc_cpuset_operations
= {
1676 .open
= cpuset_open
,
1678 .llseek
= seq_lseek
,
1679 .release
= single_release
,
1682 /* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */
1683 char *cpuset_task_status_allowed(struct task_struct
*task
, char *buffer
)
1685 buffer
+= sprintf(buffer
, "Cpus_allowed:\t");
1686 buffer
+= cpumask_scnprintf(buffer
, PAGE_SIZE
, task
->cpus_allowed
);
1687 buffer
+= sprintf(buffer
, "\n");
1688 buffer
+= sprintf(buffer
, "Mems_allowed:\t");
1689 buffer
+= nodemask_scnprintf(buffer
, PAGE_SIZE
, task
->mems_allowed
);
1690 buffer
+= sprintf(buffer
, "\n");