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9a8488965d
gcc-4 warns with include/linux/cpuset.h:21: warning: type qualifiers ignored on function return type cpuset_cpus_allowed is declared with const extern const cpumask_t cpuset_cpus_allowed(const struct task_struct *p); First const should be __attribute__((const)), but the gcc manual explains that: "Note that a function that has pointer arguments and examines the data pointed to must not be declared const. Likewise, a function that calls a non-const function usually must not be const. It does not make sense for a const function to return void." The following patch remove const from the function declaration. Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1565 lines
40 KiB
C
1565 lines
40 KiB
C
/*
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* kernel/cpuset.c
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*
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* Processor and Memory placement constraints for sets of tasks.
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*
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* Copyright (C) 2003 BULL SA.
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* Copyright (C) 2004 Silicon Graphics, Inc.
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*
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* Portions derived from Patrick Mochel's sysfs code.
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* sysfs is Copyright (c) 2001-3 Patrick Mochel
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* Portions Copyright (c) 2004 Silicon Graphics, Inc.
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*
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* 2003-10-10 Written by Simon Derr <simon.derr@bull.net>
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* 2003-10-22 Updates by Stephen Hemminger.
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* 2004 May-July Rework by Paul Jackson <pj@sgi.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of the Linux
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* distribution for more details.
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*/
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#include <linux/config.h>
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#include <linux/cpu.h>
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#include <linux/cpumask.h>
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#include <linux/cpuset.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/kmod.h>
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#include <linux/list.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
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#include <linux/pagemap.h>
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#include <linux/proc_fs.h>
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#include <linux/sched.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/smp_lock.h>
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#include <linux/spinlock.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/time.h>
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#include <linux/backing-dev.h>
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#include <linux/sort.h>
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#include <asm/uaccess.h>
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#include <asm/atomic.h>
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#include <asm/semaphore.h>
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#define CPUSET_SUPER_MAGIC 0x27e0eb
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struct cpuset {
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unsigned long flags; /* "unsigned long" so bitops work */
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cpumask_t cpus_allowed; /* CPUs allowed to tasks in cpuset */
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nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */
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atomic_t count; /* count tasks using this cpuset */
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/*
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* We link our 'sibling' struct into our parents 'children'.
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* Our children link their 'sibling' into our 'children'.
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*/
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struct list_head sibling; /* my parents children */
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struct list_head children; /* my children */
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struct cpuset *parent; /* my parent */
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struct dentry *dentry; /* cpuset fs entry */
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/*
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* Copy of global cpuset_mems_generation as of the most
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* recent time this cpuset changed its mems_allowed.
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*/
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int mems_generation;
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};
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/* bits in struct cpuset flags field */
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typedef enum {
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CS_CPU_EXCLUSIVE,
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CS_MEM_EXCLUSIVE,
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CS_REMOVED,
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CS_NOTIFY_ON_RELEASE
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} cpuset_flagbits_t;
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/* convenient tests for these bits */
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static inline int is_cpu_exclusive(const struct cpuset *cs)
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{
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return !!test_bit(CS_CPU_EXCLUSIVE, &cs->flags);
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}
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static inline int is_mem_exclusive(const struct cpuset *cs)
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{
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return !!test_bit(CS_MEM_EXCLUSIVE, &cs->flags);
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}
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static inline int is_removed(const struct cpuset *cs)
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{
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return !!test_bit(CS_REMOVED, &cs->flags);
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}
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static inline int notify_on_release(const struct cpuset *cs)
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{
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return !!test_bit(CS_NOTIFY_ON_RELEASE, &cs->flags);
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}
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/*
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* Increment this atomic integer everytime any cpuset changes its
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* mems_allowed value. Users of cpusets can track this generation
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* number, and avoid having to lock and reload mems_allowed unless
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* the cpuset they're using changes generation.
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*
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* A single, global generation is needed because attach_task() could
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* reattach a task to a different cpuset, which must not have its
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* generation numbers aliased with those of that tasks previous cpuset.
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*
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* Generations are needed for mems_allowed because one task cannot
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* modify anothers memory placement. So we must enable every task,
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* on every visit to __alloc_pages(), to efficiently check whether
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* its current->cpuset->mems_allowed has changed, requiring an update
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* of its current->mems_allowed.
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*/
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static atomic_t cpuset_mems_generation = ATOMIC_INIT(1);
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static struct cpuset top_cpuset = {
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.flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)),
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.cpus_allowed = CPU_MASK_ALL,
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.mems_allowed = NODE_MASK_ALL,
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.count = ATOMIC_INIT(0),
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.sibling = LIST_HEAD_INIT(top_cpuset.sibling),
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.children = LIST_HEAD_INIT(top_cpuset.children),
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.parent = NULL,
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.dentry = NULL,
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.mems_generation = 0,
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};
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static struct vfsmount *cpuset_mount;
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static struct super_block *cpuset_sb = NULL;
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/*
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* cpuset_sem should be held by anyone who is depending on the children
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* or sibling lists of any cpuset, or performing non-atomic operations
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* on the flags or *_allowed values of a cpuset, such as raising the
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* CS_REMOVED flag bit iff it is not already raised, or reading and
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* conditionally modifying the *_allowed values. One kernel global
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* cpuset semaphore should be sufficient - these things don't change
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* that much.
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*
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* The code that modifies cpusets holds cpuset_sem across the entire
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* operation, from cpuset_common_file_write() down, single threading
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* all cpuset modifications (except for counter manipulations from
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* fork and exit) across the system. This presumes that cpuset
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* modifications are rare - better kept simple and safe, even if slow.
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*
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* The code that reads cpusets, such as in cpuset_common_file_read()
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* and below, only holds cpuset_sem across small pieces of code, such
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* as when reading out possibly multi-word cpumasks and nodemasks, as
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* the risks are less, and the desire for performance a little greater.
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* The proc_cpuset_show() routine needs to hold cpuset_sem to insure
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* that no cs->dentry is NULL, as it walks up the cpuset tree to root.
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*
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* The hooks from fork and exit, cpuset_fork() and cpuset_exit(), don't
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* (usually) grab cpuset_sem. These are the two most performance
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* critical pieces of code here. The exception occurs on exit(),
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* if the last task using a cpuset exits, and the cpuset was marked
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* notify_on_release. In that case, the cpuset_sem is taken, the
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* path to the released cpuset calculated, and a usermode call made
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* to /sbin/cpuset_release_agent with the name of the cpuset (path
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* relative to the root of cpuset file system) as the argument.
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*
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* A cpuset can only be deleted if both its 'count' of using tasks is
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* zero, and its list of 'children' cpusets is empty. Since all tasks
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* in the system use _some_ cpuset, and since there is always at least
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* one task in the system (init, pid == 1), therefore, top_cpuset
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* always has either children cpusets and/or using tasks. So no need
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* for any special hack to ensure that top_cpuset cannot be deleted.
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*/
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static DECLARE_MUTEX(cpuset_sem);
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/*
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* A couple of forward declarations required, due to cyclic reference loop:
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* cpuset_mkdir -> cpuset_create -> cpuset_populate_dir -> cpuset_add_file
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* -> cpuset_create_file -> cpuset_dir_inode_operations -> cpuset_mkdir.
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*/
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static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode);
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static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry);
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static struct backing_dev_info cpuset_backing_dev_info = {
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.ra_pages = 0, /* No readahead */
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.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
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};
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static struct inode *cpuset_new_inode(mode_t mode)
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{
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struct inode *inode = new_inode(cpuset_sb);
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if (inode) {
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inode->i_mode = mode;
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inode->i_uid = current->fsuid;
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inode->i_gid = current->fsgid;
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inode->i_blksize = PAGE_CACHE_SIZE;
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inode->i_blocks = 0;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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inode->i_mapping->backing_dev_info = &cpuset_backing_dev_info;
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}
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return inode;
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}
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static void cpuset_diput(struct dentry *dentry, struct inode *inode)
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{
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/* is dentry a directory ? if so, kfree() associated cpuset */
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if (S_ISDIR(inode->i_mode)) {
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struct cpuset *cs = dentry->d_fsdata;
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BUG_ON(!(is_removed(cs)));
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kfree(cs);
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}
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iput(inode);
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}
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static struct dentry_operations cpuset_dops = {
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.d_iput = cpuset_diput,
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};
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static struct dentry *cpuset_get_dentry(struct dentry *parent, const char *name)
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{
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struct qstr qstr;
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struct dentry *d;
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qstr.name = name;
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qstr.len = strlen(name);
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qstr.hash = full_name_hash(name, qstr.len);
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d = lookup_hash(&qstr, parent);
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if (!IS_ERR(d))
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d->d_op = &cpuset_dops;
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return d;
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}
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static void remove_dir(struct dentry *d)
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{
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struct dentry *parent = dget(d->d_parent);
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d_delete(d);
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simple_rmdir(parent->d_inode, d);
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dput(parent);
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}
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/*
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* NOTE : the dentry must have been dget()'ed
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*/
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static void cpuset_d_remove_dir(struct dentry *dentry)
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{
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struct list_head *node;
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spin_lock(&dcache_lock);
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node = dentry->d_subdirs.next;
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while (node != &dentry->d_subdirs) {
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struct dentry *d = list_entry(node, struct dentry, d_child);
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list_del_init(node);
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if (d->d_inode) {
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d = dget_locked(d);
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spin_unlock(&dcache_lock);
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d_delete(d);
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simple_unlink(dentry->d_inode, d);
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dput(d);
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spin_lock(&dcache_lock);
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}
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node = dentry->d_subdirs.next;
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}
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list_del_init(&dentry->d_child);
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spin_unlock(&dcache_lock);
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remove_dir(dentry);
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}
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static struct super_operations cpuset_ops = {
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.statfs = simple_statfs,
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.drop_inode = generic_delete_inode,
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};
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static int cpuset_fill_super(struct super_block *sb, void *unused_data,
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int unused_silent)
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{
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struct inode *inode;
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struct dentry *root;
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sb->s_blocksize = PAGE_CACHE_SIZE;
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sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
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sb->s_magic = CPUSET_SUPER_MAGIC;
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sb->s_op = &cpuset_ops;
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cpuset_sb = sb;
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inode = cpuset_new_inode(S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR);
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if (inode) {
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inode->i_op = &simple_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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/* directories start off with i_nlink == 2 (for "." entry) */
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inode->i_nlink++;
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} else {
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return -ENOMEM;
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}
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root = d_alloc_root(inode);
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if (!root) {
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iput(inode);
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return -ENOMEM;
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}
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sb->s_root = root;
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return 0;
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}
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static struct super_block *cpuset_get_sb(struct file_system_type *fs_type,
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int flags, const char *unused_dev_name,
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void *data)
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{
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return get_sb_single(fs_type, flags, data, cpuset_fill_super);
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}
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static struct file_system_type cpuset_fs_type = {
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.name = "cpuset",
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.get_sb = cpuset_get_sb,
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.kill_sb = kill_litter_super,
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};
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/* struct cftype:
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*
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* The files in the cpuset filesystem mostly have a very simple read/write
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* handling, some common function will take care of it. Nevertheless some cases
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* (read tasks) are special and therefore I define this structure for every
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* kind of file.
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*
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*
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* When reading/writing to a file:
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* - the cpuset to use in file->f_dentry->d_parent->d_fsdata
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* - the 'cftype' of the file is file->f_dentry->d_fsdata
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*/
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struct cftype {
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char *name;
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int private;
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int (*open) (struct inode *inode, struct file *file);
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ssize_t (*read) (struct file *file, char __user *buf, size_t nbytes,
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loff_t *ppos);
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int (*write) (struct file *file, const char __user *buf, size_t nbytes,
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loff_t *ppos);
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int (*release) (struct inode *inode, struct file *file);
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};
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static inline struct cpuset *__d_cs(struct dentry *dentry)
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{
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return dentry->d_fsdata;
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}
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static inline struct cftype *__d_cft(struct dentry *dentry)
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{
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return dentry->d_fsdata;
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}
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/*
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* Call with cpuset_sem held. Writes path of cpuset into buf.
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* Returns 0 on success, -errno on error.
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*/
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static int cpuset_path(const struct cpuset *cs, char *buf, int buflen)
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{
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char *start;
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start = buf + buflen;
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*--start = '\0';
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for (;;) {
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int len = cs->dentry->d_name.len;
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if ((start -= len) < buf)
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return -ENAMETOOLONG;
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memcpy(start, cs->dentry->d_name.name, len);
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cs = cs->parent;
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if (!cs)
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break;
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if (!cs->parent)
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continue;
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if (--start < buf)
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return -ENAMETOOLONG;
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*start = '/';
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}
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memmove(buf, start, buf + buflen - start);
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return 0;
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}
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/*
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* Notify userspace when a cpuset is released, by running
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* /sbin/cpuset_release_agent with the name of the cpuset (path
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* relative to the root of cpuset file system) as the argument.
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*
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* Most likely, this user command will try to rmdir this cpuset.
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*
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* This races with the possibility that some other task will be
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* attached to this cpuset before it is removed, or that some other
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* user task will 'mkdir' a child cpuset of this cpuset. That's ok.
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* The presumed 'rmdir' will fail quietly if this cpuset is no longer
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* unused, and this cpuset will be reprieved from its death sentence,
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* to continue to serve a useful existence. Next time it's released,
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* we will get notified again, if it still has 'notify_on_release' set.
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*
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* Note final arg to call_usermodehelper() is 0 - that means
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* don't wait. Since we are holding the global cpuset_sem here,
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* and we are asking another thread (started from keventd) to rmdir a
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* cpuset, we can't wait - or we'd deadlock with the removing thread
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* on cpuset_sem.
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*/
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static int cpuset_release_agent(char *cpuset_str)
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{
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char *argv[3], *envp[3];
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int i;
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i = 0;
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argv[i++] = "/sbin/cpuset_release_agent";
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argv[i++] = cpuset_str;
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argv[i] = NULL;
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i = 0;
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/* minimal command environment */
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envp[i++] = "HOME=/";
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envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
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envp[i] = NULL;
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|
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return call_usermodehelper(argv[0], argv, envp, 0);
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}
|
|
|
|
/*
|
|
* Either cs->count of using tasks transitioned to zero, or the
|
|
* cs->children list of child cpusets just became empty. If this
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* cs is notify_on_release() and now both the user count is zero and
|
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* the list of children is empty, send notice to user land.
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|
*/
|
|
|
|
static void check_for_release(struct cpuset *cs)
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|
{
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|
if (notify_on_release(cs) && atomic_read(&cs->count) == 0 &&
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list_empty(&cs->children)) {
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char *buf;
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|
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buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
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if (!buf)
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return;
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if (cpuset_path(cs, buf, PAGE_SIZE) < 0)
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goto out;
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cpuset_release_agent(buf);
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out:
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kfree(buf);
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}
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}
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|
|
/*
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|
* Return in *pmask the portion of a cpusets's cpus_allowed that
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* are online. If none are online, walk up the cpuset hierarchy
|
|
* until we find one that does have some online cpus. If we get
|
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* all the way to the top and still haven't found any online cpus,
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* return cpu_online_map. Or if passed a NULL cs from an exit'ing
|
|
* task, return cpu_online_map.
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|
*
|
|
* One way or another, we guarantee to return some non-empty subset
|
|
* of cpu_online_map.
|
|
*
|
|
* Call with cpuset_sem held.
|
|
*/
|
|
|
|
static void guarantee_online_cpus(const struct cpuset *cs, cpumask_t *pmask)
|
|
{
|
|
while (cs && !cpus_intersects(cs->cpus_allowed, cpu_online_map))
|
|
cs = cs->parent;
|
|
if (cs)
|
|
cpus_and(*pmask, cs->cpus_allowed, cpu_online_map);
|
|
else
|
|
*pmask = cpu_online_map;
|
|
BUG_ON(!cpus_intersects(*pmask, cpu_online_map));
|
|
}
|
|
|
|
/*
|
|
* Return in *pmask the portion of a cpusets's mems_allowed that
|
|
* are online. If none are online, walk up the cpuset hierarchy
|
|
* until we find one that does have some online mems. If we get
|
|
* all the way to the top and still haven't found any online mems,
|
|
* return node_online_map.
|
|
*
|
|
* One way or another, we guarantee to return some non-empty subset
|
|
* of node_online_map.
|
|
*
|
|
* Call with cpuset_sem held.
|
|
*/
|
|
|
|
static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
|
|
{
|
|
while (cs && !nodes_intersects(cs->mems_allowed, node_online_map))
|
|
cs = cs->parent;
|
|
if (cs)
|
|
nodes_and(*pmask, cs->mems_allowed, node_online_map);
|
|
else
|
|
*pmask = node_online_map;
|
|
BUG_ON(!nodes_intersects(*pmask, node_online_map));
|
|
}
|
|
|
|
/*
|
|
* Refresh current tasks mems_allowed and mems_generation from
|
|
* current tasks cpuset. Call with cpuset_sem held.
|
|
*
|
|
* Be sure to call refresh_mems() on any cpuset operation which
|
|
* (1) holds cpuset_sem, and (2) might possibly alloc memory.
|
|
* Call after obtaining cpuset_sem lock, before any possible
|
|
* allocation. Otherwise one risks trying to allocate memory
|
|
* while the task cpuset_mems_generation is not the same as
|
|
* the mems_generation in its cpuset, which would deadlock on
|
|
* cpuset_sem in cpuset_update_current_mems_allowed().
|
|
*
|
|
* Since we hold cpuset_sem, once refresh_mems() is called, the
|
|
* test (current->cpuset_mems_generation != cs->mems_generation)
|
|
* in cpuset_update_current_mems_allowed() will remain false,
|
|
* until we drop cpuset_sem. Anyone else who would change our
|
|
* cpusets mems_generation needs to lock cpuset_sem first.
|
|
*/
|
|
|
|
static void refresh_mems(void)
|
|
{
|
|
struct cpuset *cs = current->cpuset;
|
|
|
|
if (current->cpuset_mems_generation != cs->mems_generation) {
|
|
guarantee_online_mems(cs, ¤t->mems_allowed);
|
|
current->cpuset_mems_generation = cs->mems_generation;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q?
|
|
*
|
|
* One cpuset is a subset of another if all its allowed CPUs and
|
|
* Memory Nodes are a subset of the other, and its exclusive flags
|
|
* are only set if the other's are set.
|
|
*/
|
|
|
|
static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
|
|
{
|
|
return cpus_subset(p->cpus_allowed, q->cpus_allowed) &&
|
|
nodes_subset(p->mems_allowed, q->mems_allowed) &&
|
|
is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
|
|
is_mem_exclusive(p) <= is_mem_exclusive(q);
|
|
}
|
|
|
|
/*
|
|
* validate_change() - Used to validate that any proposed cpuset change
|
|
* follows the structural rules for cpusets.
|
|
*
|
|
* If we replaced the flag and mask values of the current cpuset
|
|
* (cur) with those values in the trial cpuset (trial), would
|
|
* our various subset and exclusive rules still be valid? Presumes
|
|
* cpuset_sem held.
|
|
*
|
|
* 'cur' is the address of an actual, in-use cpuset. Operations
|
|
* such as list traversal that depend on the actual address of the
|
|
* cpuset in the list must use cur below, not trial.
|
|
*
|
|
* 'trial' is the address of bulk structure copy of cur, with
|
|
* perhaps one or more of the fields cpus_allowed, mems_allowed,
|
|
* or flags changed to new, trial values.
|
|
*
|
|
* Return 0 if valid, -errno if not.
|
|
*/
|
|
|
|
static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
|
|
{
|
|
struct cpuset *c, *par;
|
|
|
|
/* Each of our child cpusets must be a subset of us */
|
|
list_for_each_entry(c, &cur->children, sibling) {
|
|
if (!is_cpuset_subset(c, trial))
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* Remaining checks don't apply to root cpuset */
|
|
if ((par = cur->parent) == NULL)
|
|
return 0;
|
|
|
|
/* We must be a subset of our parent cpuset */
|
|
if (!is_cpuset_subset(trial, par))
|
|
return -EACCES;
|
|
|
|
/* If either I or some sibling (!= me) is exclusive, we can't overlap */
|
|
list_for_each_entry(c, &par->children, sibling) {
|
|
if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
|
|
c != cur &&
|
|
cpus_intersects(trial->cpus_allowed, c->cpus_allowed))
|
|
return -EINVAL;
|
|
if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
|
|
c != cur &&
|
|
nodes_intersects(trial->mems_allowed, c->mems_allowed))
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int update_cpumask(struct cpuset *cs, char *buf)
|
|
{
|
|
struct cpuset trialcs;
|
|
int retval;
|
|
|
|
trialcs = *cs;
|
|
retval = cpulist_parse(buf, trialcs.cpus_allowed);
|
|
if (retval < 0)
|
|
return retval;
|
|
cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
|
|
if (cpus_empty(trialcs.cpus_allowed))
|
|
return -ENOSPC;
|
|
retval = validate_change(cs, &trialcs);
|
|
if (retval == 0)
|
|
cs->cpus_allowed = trialcs.cpus_allowed;
|
|
return retval;
|
|
}
|
|
|
|
static int update_nodemask(struct cpuset *cs, char *buf)
|
|
{
|
|
struct cpuset trialcs;
|
|
int retval;
|
|
|
|
trialcs = *cs;
|
|
retval = nodelist_parse(buf, trialcs.mems_allowed);
|
|
if (retval < 0)
|
|
return retval;
|
|
nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map);
|
|
if (nodes_empty(trialcs.mems_allowed))
|
|
return -ENOSPC;
|
|
retval = validate_change(cs, &trialcs);
|
|
if (retval == 0) {
|
|
cs->mems_allowed = trialcs.mems_allowed;
|
|
atomic_inc(&cpuset_mems_generation);
|
|
cs->mems_generation = atomic_read(&cpuset_mems_generation);
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* update_flag - read a 0 or a 1 in a file and update associated flag
|
|
* bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE,
|
|
* CS_NOTIFY_ON_RELEASE)
|
|
* cs: the cpuset to update
|
|
* buf: the buffer where we read the 0 or 1
|
|
*/
|
|
|
|
static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
|
|
{
|
|
int turning_on;
|
|
struct cpuset trialcs;
|
|
int err;
|
|
|
|
turning_on = (simple_strtoul(buf, NULL, 10) != 0);
|
|
|
|
trialcs = *cs;
|
|
if (turning_on)
|
|
set_bit(bit, &trialcs.flags);
|
|
else
|
|
clear_bit(bit, &trialcs.flags);
|
|
|
|
err = validate_change(cs, &trialcs);
|
|
if (err == 0) {
|
|
if (turning_on)
|
|
set_bit(bit, &cs->flags);
|
|
else
|
|
clear_bit(bit, &cs->flags);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int attach_task(struct cpuset *cs, char *buf)
|
|
{
|
|
pid_t pid;
|
|
struct task_struct *tsk;
|
|
struct cpuset *oldcs;
|
|
cpumask_t cpus;
|
|
|
|
if (sscanf(buf, "%d", &pid) != 1)
|
|
return -EIO;
|
|
if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
|
|
return -ENOSPC;
|
|
|
|
if (pid) {
|
|
read_lock(&tasklist_lock);
|
|
|
|
tsk = find_task_by_pid(pid);
|
|
if (!tsk) {
|
|
read_unlock(&tasklist_lock);
|
|
return -ESRCH;
|
|
}
|
|
|
|
get_task_struct(tsk);
|
|
read_unlock(&tasklist_lock);
|
|
|
|
if ((current->euid) && (current->euid != tsk->uid)
|
|
&& (current->euid != tsk->suid)) {
|
|
put_task_struct(tsk);
|
|
return -EACCES;
|
|
}
|
|
} else {
|
|
tsk = current;
|
|
get_task_struct(tsk);
|
|
}
|
|
|
|
task_lock(tsk);
|
|
oldcs = tsk->cpuset;
|
|
if (!oldcs) {
|
|
task_unlock(tsk);
|
|
put_task_struct(tsk);
|
|
return -ESRCH;
|
|
}
|
|
atomic_inc(&cs->count);
|
|
tsk->cpuset = cs;
|
|
task_unlock(tsk);
|
|
|
|
guarantee_online_cpus(cs, &cpus);
|
|
set_cpus_allowed(tsk, cpus);
|
|
|
|
put_task_struct(tsk);
|
|
if (atomic_dec_and_test(&oldcs->count))
|
|
check_for_release(oldcs);
|
|
return 0;
|
|
}
|
|
|
|
/* The various types of files and directories in a cpuset file system */
|
|
|
|
typedef enum {
|
|
FILE_ROOT,
|
|
FILE_DIR,
|
|
FILE_CPULIST,
|
|
FILE_MEMLIST,
|
|
FILE_CPU_EXCLUSIVE,
|
|
FILE_MEM_EXCLUSIVE,
|
|
FILE_NOTIFY_ON_RELEASE,
|
|
FILE_TASKLIST,
|
|
} cpuset_filetype_t;
|
|
|
|
static ssize_t cpuset_common_file_write(struct file *file, const char __user *userbuf,
|
|
size_t nbytes, loff_t *unused_ppos)
|
|
{
|
|
struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
|
|
struct cftype *cft = __d_cft(file->f_dentry);
|
|
cpuset_filetype_t type = cft->private;
|
|
char *buffer;
|
|
int retval = 0;
|
|
|
|
/* Crude upper limit on largest legitimate cpulist user might write. */
|
|
if (nbytes > 100 + 6 * NR_CPUS)
|
|
return -E2BIG;
|
|
|
|
/* +1 for nul-terminator */
|
|
if ((buffer = kmalloc(nbytes + 1, GFP_KERNEL)) == 0)
|
|
return -ENOMEM;
|
|
|
|
if (copy_from_user(buffer, userbuf, nbytes)) {
|
|
retval = -EFAULT;
|
|
goto out1;
|
|
}
|
|
buffer[nbytes] = 0; /* nul-terminate */
|
|
|
|
down(&cpuset_sem);
|
|
|
|
if (is_removed(cs)) {
|
|
retval = -ENODEV;
|
|
goto out2;
|
|
}
|
|
|
|
switch (type) {
|
|
case FILE_CPULIST:
|
|
retval = update_cpumask(cs, buffer);
|
|
break;
|
|
case FILE_MEMLIST:
|
|
retval = update_nodemask(cs, buffer);
|
|
break;
|
|
case FILE_CPU_EXCLUSIVE:
|
|
retval = update_flag(CS_CPU_EXCLUSIVE, cs, buffer);
|
|
break;
|
|
case FILE_MEM_EXCLUSIVE:
|
|
retval = update_flag(CS_MEM_EXCLUSIVE, cs, buffer);
|
|
break;
|
|
case FILE_NOTIFY_ON_RELEASE:
|
|
retval = update_flag(CS_NOTIFY_ON_RELEASE, cs, buffer);
|
|
break;
|
|
case FILE_TASKLIST:
|
|
retval = attach_task(cs, buffer);
|
|
break;
|
|
default:
|
|
retval = -EINVAL;
|
|
goto out2;
|
|
}
|
|
|
|
if (retval == 0)
|
|
retval = nbytes;
|
|
out2:
|
|
up(&cpuset_sem);
|
|
out1:
|
|
kfree(buffer);
|
|
return retval;
|
|
}
|
|
|
|
static ssize_t cpuset_file_write(struct file *file, const char __user *buf,
|
|
size_t nbytes, loff_t *ppos)
|
|
{
|
|
ssize_t retval = 0;
|
|
struct cftype *cft = __d_cft(file->f_dentry);
|
|
if (!cft)
|
|
return -ENODEV;
|
|
|
|
/* special function ? */
|
|
if (cft->write)
|
|
retval = cft->write(file, buf, nbytes, ppos);
|
|
else
|
|
retval = cpuset_common_file_write(file, buf, nbytes, ppos);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* These ascii lists should be read in a single call, by using a user
|
|
* buffer large enough to hold the entire map. If read in smaller
|
|
* chunks, there is no guarantee of atomicity. Since the display format
|
|
* used, list of ranges of sequential numbers, is variable length,
|
|
* and since these maps can change value dynamically, one could read
|
|
* gibberish by doing partial reads while a list was changing.
|
|
* A single large read to a buffer that crosses a page boundary is
|
|
* ok, because the result being copied to user land is not recomputed
|
|
* across a page fault.
|
|
*/
|
|
|
|
static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
|
|
{
|
|
cpumask_t mask;
|
|
|
|
down(&cpuset_sem);
|
|
mask = cs->cpus_allowed;
|
|
up(&cpuset_sem);
|
|
|
|
return cpulist_scnprintf(page, PAGE_SIZE, mask);
|
|
}
|
|
|
|
static int cpuset_sprintf_memlist(char *page, struct cpuset *cs)
|
|
{
|
|
nodemask_t mask;
|
|
|
|
down(&cpuset_sem);
|
|
mask = cs->mems_allowed;
|
|
up(&cpuset_sem);
|
|
|
|
return nodelist_scnprintf(page, PAGE_SIZE, mask);
|
|
}
|
|
|
|
static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
|
|
size_t nbytes, loff_t *ppos)
|
|
{
|
|
struct cftype *cft = __d_cft(file->f_dentry);
|
|
struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
|
|
cpuset_filetype_t type = cft->private;
|
|
char *page;
|
|
ssize_t retval = 0;
|
|
char *s;
|
|
char *start;
|
|
size_t n;
|
|
|
|
if (!(page = (char *)__get_free_page(GFP_KERNEL)))
|
|
return -ENOMEM;
|
|
|
|
s = page;
|
|
|
|
switch (type) {
|
|
case FILE_CPULIST:
|
|
s += cpuset_sprintf_cpulist(s, cs);
|
|
break;
|
|
case FILE_MEMLIST:
|
|
s += cpuset_sprintf_memlist(s, cs);
|
|
break;
|
|
case FILE_CPU_EXCLUSIVE:
|
|
*s++ = is_cpu_exclusive(cs) ? '1' : '0';
|
|
break;
|
|
case FILE_MEM_EXCLUSIVE:
|
|
*s++ = is_mem_exclusive(cs) ? '1' : '0';
|
|
break;
|
|
case FILE_NOTIFY_ON_RELEASE:
|
|
*s++ = notify_on_release(cs) ? '1' : '0';
|
|
break;
|
|
default:
|
|
retval = -EINVAL;
|
|
goto out;
|
|
}
|
|
*s++ = '\n';
|
|
*s = '\0';
|
|
|
|
start = page + *ppos;
|
|
n = s - start;
|
|
retval = n - copy_to_user(buf, start, min(n, nbytes));
|
|
*ppos += retval;
|
|
out:
|
|
free_page((unsigned long)page);
|
|
return retval;
|
|
}
|
|
|
|
static ssize_t cpuset_file_read(struct file *file, char __user *buf, size_t nbytes,
|
|
loff_t *ppos)
|
|
{
|
|
ssize_t retval = 0;
|
|
struct cftype *cft = __d_cft(file->f_dentry);
|
|
if (!cft)
|
|
return -ENODEV;
|
|
|
|
/* special function ? */
|
|
if (cft->read)
|
|
retval = cft->read(file, buf, nbytes, ppos);
|
|
else
|
|
retval = cpuset_common_file_read(file, buf, nbytes, ppos);
|
|
|
|
return retval;
|
|
}
|
|
|
|
static int cpuset_file_open(struct inode *inode, struct file *file)
|
|
{
|
|
int err;
|
|
struct cftype *cft;
|
|
|
|
err = generic_file_open(inode, file);
|
|
if (err)
|
|
return err;
|
|
|
|
cft = __d_cft(file->f_dentry);
|
|
if (!cft)
|
|
return -ENODEV;
|
|
if (cft->open)
|
|
err = cft->open(inode, file);
|
|
else
|
|
err = 0;
|
|
|
|
return err;
|
|
}
|
|
|
|
static int cpuset_file_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct cftype *cft = __d_cft(file->f_dentry);
|
|
if (cft->release)
|
|
return cft->release(inode, file);
|
|
return 0;
|
|
}
|
|
|
|
static struct file_operations cpuset_file_operations = {
|
|
.read = cpuset_file_read,
|
|
.write = cpuset_file_write,
|
|
.llseek = generic_file_llseek,
|
|
.open = cpuset_file_open,
|
|
.release = cpuset_file_release,
|
|
};
|
|
|
|
static struct inode_operations cpuset_dir_inode_operations = {
|
|
.lookup = simple_lookup,
|
|
.mkdir = cpuset_mkdir,
|
|
.rmdir = cpuset_rmdir,
|
|
};
|
|
|
|
static int cpuset_create_file(struct dentry *dentry, int mode)
|
|
{
|
|
struct inode *inode;
|
|
|
|
if (!dentry)
|
|
return -ENOENT;
|
|
if (dentry->d_inode)
|
|
return -EEXIST;
|
|
|
|
inode = cpuset_new_inode(mode);
|
|
if (!inode)
|
|
return -ENOMEM;
|
|
|
|
if (S_ISDIR(mode)) {
|
|
inode->i_op = &cpuset_dir_inode_operations;
|
|
inode->i_fop = &simple_dir_operations;
|
|
|
|
/* start off with i_nlink == 2 (for "." entry) */
|
|
inode->i_nlink++;
|
|
} else if (S_ISREG(mode)) {
|
|
inode->i_size = 0;
|
|
inode->i_fop = &cpuset_file_operations;
|
|
}
|
|
|
|
d_instantiate(dentry, inode);
|
|
dget(dentry); /* Extra count - pin the dentry in core */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* cpuset_create_dir - create a directory for an object.
|
|
* cs: the cpuset we create the directory for.
|
|
* It must have a valid ->parent field
|
|
* And we are going to fill its ->dentry field.
|
|
* name: The name to give to the cpuset directory. Will be copied.
|
|
* mode: mode to set on new directory.
|
|
*/
|
|
|
|
static int cpuset_create_dir(struct cpuset *cs, const char *name, int mode)
|
|
{
|
|
struct dentry *dentry = NULL;
|
|
struct dentry *parent;
|
|
int error = 0;
|
|
|
|
parent = cs->parent->dentry;
|
|
dentry = cpuset_get_dentry(parent, name);
|
|
if (IS_ERR(dentry))
|
|
return PTR_ERR(dentry);
|
|
error = cpuset_create_file(dentry, S_IFDIR | mode);
|
|
if (!error) {
|
|
dentry->d_fsdata = cs;
|
|
parent->d_inode->i_nlink++;
|
|
cs->dentry = dentry;
|
|
}
|
|
dput(dentry);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int cpuset_add_file(struct dentry *dir, const struct cftype *cft)
|
|
{
|
|
struct dentry *dentry;
|
|
int error;
|
|
|
|
down(&dir->d_inode->i_sem);
|
|
dentry = cpuset_get_dentry(dir, cft->name);
|
|
if (!IS_ERR(dentry)) {
|
|
error = cpuset_create_file(dentry, 0644 | S_IFREG);
|
|
if (!error)
|
|
dentry->d_fsdata = (void *)cft;
|
|
dput(dentry);
|
|
} else
|
|
error = PTR_ERR(dentry);
|
|
up(&dir->d_inode->i_sem);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Stuff for reading the 'tasks' file.
|
|
*
|
|
* Reading this file can return large amounts of data if a cpuset has
|
|
* *lots* of attached tasks. So it may need several calls to read(),
|
|
* but we cannot guarantee that the information we produce is correct
|
|
* unless we produce it entirely atomically.
|
|
*
|
|
* Upon tasks file open(), a struct ctr_struct is allocated, that
|
|
* will have a pointer to an array (also allocated here). The struct
|
|
* ctr_struct * is stored in file->private_data. Its resources will
|
|
* be freed by release() when the file is closed. The array is used
|
|
* to sprintf the PIDs and then used by read().
|
|
*/
|
|
|
|
/* cpusets_tasks_read array */
|
|
|
|
struct ctr_struct {
|
|
char *buf;
|
|
int bufsz;
|
|
};
|
|
|
|
/*
|
|
* Load into 'pidarray' up to 'npids' of the tasks using cpuset 'cs'.
|
|
* Return actual number of pids loaded.
|
|
*/
|
|
static inline int pid_array_load(pid_t *pidarray, int npids, struct cpuset *cs)
|
|
{
|
|
int n = 0;
|
|
struct task_struct *g, *p;
|
|
|
|
read_lock(&tasklist_lock);
|
|
|
|
do_each_thread(g, p) {
|
|
if (p->cpuset == cs) {
|
|
pidarray[n++] = p->pid;
|
|
if (unlikely(n == npids))
|
|
goto array_full;
|
|
}
|
|
} while_each_thread(g, p);
|
|
|
|
array_full:
|
|
read_unlock(&tasklist_lock);
|
|
return n;
|
|
}
|
|
|
|
static int cmppid(const void *a, const void *b)
|
|
{
|
|
return *(pid_t *)a - *(pid_t *)b;
|
|
}
|
|
|
|
/*
|
|
* Convert array 'a' of 'npids' pid_t's to a string of newline separated
|
|
* decimal pids in 'buf'. Don't write more than 'sz' chars, but return
|
|
* count 'cnt' of how many chars would be written if buf were large enough.
|
|
*/
|
|
static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids)
|
|
{
|
|
int cnt = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < npids; i++)
|
|
cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]);
|
|
return cnt;
|
|
}
|
|
|
|
static int cpuset_tasks_open(struct inode *unused, struct file *file)
|
|
{
|
|
struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
|
|
struct ctr_struct *ctr;
|
|
pid_t *pidarray;
|
|
int npids;
|
|
char c;
|
|
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return 0;
|
|
|
|
ctr = kmalloc(sizeof(*ctr), GFP_KERNEL);
|
|
if (!ctr)
|
|
goto err0;
|
|
|
|
/*
|
|
* If cpuset gets more users after we read count, we won't have
|
|
* enough space - tough. This race is indistinguishable to the
|
|
* caller from the case that the additional cpuset users didn't
|
|
* show up until sometime later on.
|
|
*/
|
|
npids = atomic_read(&cs->count);
|
|
pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL);
|
|
if (!pidarray)
|
|
goto err1;
|
|
|
|
npids = pid_array_load(pidarray, npids, cs);
|
|
sort(pidarray, npids, sizeof(pid_t), cmppid, NULL);
|
|
|
|
/* Call pid_array_to_buf() twice, first just to get bufsz */
|
|
ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1;
|
|
ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL);
|
|
if (!ctr->buf)
|
|
goto err2;
|
|
ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids);
|
|
|
|
kfree(pidarray);
|
|
file->private_data = ctr;
|
|
return 0;
|
|
|
|
err2:
|
|
kfree(pidarray);
|
|
err1:
|
|
kfree(ctr);
|
|
err0:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static ssize_t cpuset_tasks_read(struct file *file, char __user *buf,
|
|
size_t nbytes, loff_t *ppos)
|
|
{
|
|
struct ctr_struct *ctr = file->private_data;
|
|
|
|
if (*ppos + nbytes > ctr->bufsz)
|
|
nbytes = ctr->bufsz - *ppos;
|
|
if (copy_to_user(buf, ctr->buf + *ppos, nbytes))
|
|
return -EFAULT;
|
|
*ppos += nbytes;
|
|
return nbytes;
|
|
}
|
|
|
|
static int cpuset_tasks_release(struct inode *unused_inode, struct file *file)
|
|
{
|
|
struct ctr_struct *ctr;
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
ctr = file->private_data;
|
|
kfree(ctr->buf);
|
|
kfree(ctr);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* for the common functions, 'private' gives the type of file
|
|
*/
|
|
|
|
static struct cftype cft_tasks = {
|
|
.name = "tasks",
|
|
.open = cpuset_tasks_open,
|
|
.read = cpuset_tasks_read,
|
|
.release = cpuset_tasks_release,
|
|
.private = FILE_TASKLIST,
|
|
};
|
|
|
|
static struct cftype cft_cpus = {
|
|
.name = "cpus",
|
|
.private = FILE_CPULIST,
|
|
};
|
|
|
|
static struct cftype cft_mems = {
|
|
.name = "mems",
|
|
.private = FILE_MEMLIST,
|
|
};
|
|
|
|
static struct cftype cft_cpu_exclusive = {
|
|
.name = "cpu_exclusive",
|
|
.private = FILE_CPU_EXCLUSIVE,
|
|
};
|
|
|
|
static struct cftype cft_mem_exclusive = {
|
|
.name = "mem_exclusive",
|
|
.private = FILE_MEM_EXCLUSIVE,
|
|
};
|
|
|
|
static struct cftype cft_notify_on_release = {
|
|
.name = "notify_on_release",
|
|
.private = FILE_NOTIFY_ON_RELEASE,
|
|
};
|
|
|
|
static int cpuset_populate_dir(struct dentry *cs_dentry)
|
|
{
|
|
int err;
|
|
|
|
if ((err = cpuset_add_file(cs_dentry, &cft_cpus)) < 0)
|
|
return err;
|
|
if ((err = cpuset_add_file(cs_dentry, &cft_mems)) < 0)
|
|
return err;
|
|
if ((err = cpuset_add_file(cs_dentry, &cft_cpu_exclusive)) < 0)
|
|
return err;
|
|
if ((err = cpuset_add_file(cs_dentry, &cft_mem_exclusive)) < 0)
|
|
return err;
|
|
if ((err = cpuset_add_file(cs_dentry, &cft_notify_on_release)) < 0)
|
|
return err;
|
|
if ((err = cpuset_add_file(cs_dentry, &cft_tasks)) < 0)
|
|
return err;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* cpuset_create - create a cpuset
|
|
* parent: cpuset that will be parent of the new cpuset.
|
|
* name: name of the new cpuset. Will be strcpy'ed.
|
|
* mode: mode to set on new inode
|
|
*
|
|
* Must be called with the semaphore on the parent inode held
|
|
*/
|
|
|
|
static long cpuset_create(struct cpuset *parent, const char *name, int mode)
|
|
{
|
|
struct cpuset *cs;
|
|
int err;
|
|
|
|
cs = kmalloc(sizeof(*cs), GFP_KERNEL);
|
|
if (!cs)
|
|
return -ENOMEM;
|
|
|
|
down(&cpuset_sem);
|
|
refresh_mems();
|
|
cs->flags = 0;
|
|
if (notify_on_release(parent))
|
|
set_bit(CS_NOTIFY_ON_RELEASE, &cs->flags);
|
|
cs->cpus_allowed = CPU_MASK_NONE;
|
|
cs->mems_allowed = NODE_MASK_NONE;
|
|
atomic_set(&cs->count, 0);
|
|
INIT_LIST_HEAD(&cs->sibling);
|
|
INIT_LIST_HEAD(&cs->children);
|
|
atomic_inc(&cpuset_mems_generation);
|
|
cs->mems_generation = atomic_read(&cpuset_mems_generation);
|
|
|
|
cs->parent = parent;
|
|
|
|
list_add(&cs->sibling, &cs->parent->children);
|
|
|
|
err = cpuset_create_dir(cs, name, mode);
|
|
if (err < 0)
|
|
goto err;
|
|
|
|
/*
|
|
* Release cpuset_sem before cpuset_populate_dir() because it
|
|
* will down() this new directory's i_sem and if we race with
|
|
* another mkdir, we might deadlock.
|
|
*/
|
|
up(&cpuset_sem);
|
|
|
|
err = cpuset_populate_dir(cs->dentry);
|
|
/* If err < 0, we have a half-filled directory - oh well ;) */
|
|
return 0;
|
|
err:
|
|
list_del(&cs->sibling);
|
|
up(&cpuset_sem);
|
|
kfree(cs);
|
|
return err;
|
|
}
|
|
|
|
static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode)
|
|
{
|
|
struct cpuset *c_parent = dentry->d_parent->d_fsdata;
|
|
|
|
/* the vfs holds inode->i_sem already */
|
|
return cpuset_create(c_parent, dentry->d_name.name, mode | S_IFDIR);
|
|
}
|
|
|
|
static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
|
|
{
|
|
struct cpuset *cs = dentry->d_fsdata;
|
|
struct dentry *d;
|
|
struct cpuset *parent;
|
|
|
|
/* the vfs holds both inode->i_sem already */
|
|
|
|
down(&cpuset_sem);
|
|
refresh_mems();
|
|
if (atomic_read(&cs->count) > 0) {
|
|
up(&cpuset_sem);
|
|
return -EBUSY;
|
|
}
|
|
if (!list_empty(&cs->children)) {
|
|
up(&cpuset_sem);
|
|
return -EBUSY;
|
|
}
|
|
spin_lock(&cs->dentry->d_lock);
|
|
parent = cs->parent;
|
|
set_bit(CS_REMOVED, &cs->flags);
|
|
list_del(&cs->sibling); /* delete my sibling from parent->children */
|
|
if (list_empty(&parent->children))
|
|
check_for_release(parent);
|
|
d = dget(cs->dentry);
|
|
cs->dentry = NULL;
|
|
spin_unlock(&d->d_lock);
|
|
cpuset_d_remove_dir(d);
|
|
dput(d);
|
|
up(&cpuset_sem);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* cpuset_init - initialize cpusets at system boot
|
|
*
|
|
* Description: Initialize top_cpuset and the cpuset internal file system,
|
|
**/
|
|
|
|
int __init cpuset_init(void)
|
|
{
|
|
struct dentry *root;
|
|
int err;
|
|
|
|
top_cpuset.cpus_allowed = CPU_MASK_ALL;
|
|
top_cpuset.mems_allowed = NODE_MASK_ALL;
|
|
|
|
atomic_inc(&cpuset_mems_generation);
|
|
top_cpuset.mems_generation = atomic_read(&cpuset_mems_generation);
|
|
|
|
init_task.cpuset = &top_cpuset;
|
|
|
|
err = register_filesystem(&cpuset_fs_type);
|
|
if (err < 0)
|
|
goto out;
|
|
cpuset_mount = kern_mount(&cpuset_fs_type);
|
|
if (IS_ERR(cpuset_mount)) {
|
|
printk(KERN_ERR "cpuset: could not mount!\n");
|
|
err = PTR_ERR(cpuset_mount);
|
|
cpuset_mount = NULL;
|
|
goto out;
|
|
}
|
|
root = cpuset_mount->mnt_sb->s_root;
|
|
root->d_fsdata = &top_cpuset;
|
|
root->d_inode->i_nlink++;
|
|
top_cpuset.dentry = root;
|
|
root->d_inode->i_op = &cpuset_dir_inode_operations;
|
|
err = cpuset_populate_dir(root);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* cpuset_init_smp - initialize cpus_allowed
|
|
*
|
|
* Description: Finish top cpuset after cpu, node maps are initialized
|
|
**/
|
|
|
|
void __init cpuset_init_smp(void)
|
|
{
|
|
top_cpuset.cpus_allowed = cpu_online_map;
|
|
top_cpuset.mems_allowed = node_online_map;
|
|
}
|
|
|
|
/**
|
|
* cpuset_fork - attach newly forked task to its parents cpuset.
|
|
* @p: pointer to task_struct of forking parent process.
|
|
*
|
|
* Description: By default, on fork, a task inherits its
|
|
* parents cpuset. The pointer to the shared cpuset is
|
|
* automatically copied in fork.c by dup_task_struct().
|
|
* This cpuset_fork() routine need only increment the usage
|
|
* counter in that cpuset.
|
|
**/
|
|
|
|
void cpuset_fork(struct task_struct *tsk)
|
|
{
|
|
atomic_inc(&tsk->cpuset->count);
|
|
}
|
|
|
|
/**
|
|
* cpuset_exit - detach cpuset from exiting task
|
|
* @tsk: pointer to task_struct of exiting process
|
|
*
|
|
* Description: Detach cpuset from @tsk and release it.
|
|
*
|
|
**/
|
|
|
|
void cpuset_exit(struct task_struct *tsk)
|
|
{
|
|
struct cpuset *cs;
|
|
|
|
task_lock(tsk);
|
|
cs = tsk->cpuset;
|
|
tsk->cpuset = NULL;
|
|
task_unlock(tsk);
|
|
|
|
if (atomic_dec_and_test(&cs->count)) {
|
|
down(&cpuset_sem);
|
|
check_for_release(cs);
|
|
up(&cpuset_sem);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
|
|
* @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
|
|
*
|
|
* Description: Returns the cpumask_t cpus_allowed of the cpuset
|
|
* attached to the specified @tsk. Guaranteed to return some non-empty
|
|
* subset of cpu_online_map, even if this means going outside the
|
|
* tasks cpuset.
|
|
**/
|
|
|
|
cpumask_t cpuset_cpus_allowed(const struct task_struct *tsk)
|
|
{
|
|
cpumask_t mask;
|
|
|
|
down(&cpuset_sem);
|
|
task_lock((struct task_struct *)tsk);
|
|
guarantee_online_cpus(tsk->cpuset, &mask);
|
|
task_unlock((struct task_struct *)tsk);
|
|
up(&cpuset_sem);
|
|
|
|
return mask;
|
|
}
|
|
|
|
void cpuset_init_current_mems_allowed(void)
|
|
{
|
|
current->mems_allowed = NODE_MASK_ALL;
|
|
}
|
|
|
|
/*
|
|
* If the current tasks cpusets mems_allowed changed behind our backs,
|
|
* update current->mems_allowed and mems_generation to the new value.
|
|
* Do not call this routine if in_interrupt().
|
|
*/
|
|
|
|
void cpuset_update_current_mems_allowed(void)
|
|
{
|
|
struct cpuset *cs = current->cpuset;
|
|
|
|
if (!cs)
|
|
return; /* task is exiting */
|
|
if (current->cpuset_mems_generation != cs->mems_generation) {
|
|
down(&cpuset_sem);
|
|
refresh_mems();
|
|
up(&cpuset_sem);
|
|
}
|
|
}
|
|
|
|
void cpuset_restrict_to_mems_allowed(unsigned long *nodes)
|
|
{
|
|
bitmap_and(nodes, nodes, nodes_addr(current->mems_allowed),
|
|
MAX_NUMNODES);
|
|
}
|
|
|
|
/*
|
|
* Are any of the nodes on zonelist zl allowed in current->mems_allowed?
|
|
*/
|
|
int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; zl->zones[i]; i++) {
|
|
int nid = zl->zones[i]->zone_pgdat->node_id;
|
|
|
|
if (node_isset(nid, current->mems_allowed))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Is 'current' valid, and is zone z allowed in current->mems_allowed?
|
|
*/
|
|
int cpuset_zone_allowed(struct zone *z)
|
|
{
|
|
return in_interrupt() ||
|
|
node_isset(z->zone_pgdat->node_id, current->mems_allowed);
|
|
}
|
|
|
|
/*
|
|
* proc_cpuset_show()
|
|
* - Print tasks cpuset path into seq_file.
|
|
* - Used for /proc/<pid>/cpuset.
|
|
*/
|
|
|
|
static int proc_cpuset_show(struct seq_file *m, void *v)
|
|
{
|
|
struct cpuset *cs;
|
|
struct task_struct *tsk;
|
|
char *buf;
|
|
int retval = 0;
|
|
|
|
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
tsk = m->private;
|
|
down(&cpuset_sem);
|
|
task_lock(tsk);
|
|
cs = tsk->cpuset;
|
|
task_unlock(tsk);
|
|
if (!cs) {
|
|
retval = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
retval = cpuset_path(cs, buf, PAGE_SIZE);
|
|
if (retval < 0)
|
|
goto out;
|
|
seq_puts(m, buf);
|
|
seq_putc(m, '\n');
|
|
out:
|
|
up(&cpuset_sem);
|
|
kfree(buf);
|
|
return retval;
|
|
}
|
|
|
|
static int cpuset_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct task_struct *tsk = PROC_I(inode)->task;
|
|
return single_open(file, proc_cpuset_show, tsk);
|
|
}
|
|
|
|
struct file_operations proc_cpuset_operations = {
|
|
.open = cpuset_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
/* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */
|
|
char *cpuset_task_status_allowed(struct task_struct *task, char *buffer)
|
|
{
|
|
buffer += sprintf(buffer, "Cpus_allowed:\t");
|
|
buffer += cpumask_scnprintf(buffer, PAGE_SIZE, task->cpus_allowed);
|
|
buffer += sprintf(buffer, "\n");
|
|
buffer += sprintf(buffer, "Mems_allowed:\t");
|
|
buffer += nodemask_scnprintf(buffer, PAGE_SIZE, task->mems_allowed);
|
|
buffer += sprintf(buffer, "\n");
|
|
return buffer;
|
|
}
|