fork.c
上传用户:lgb322
上传日期:2013-02-24
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文件大小:19k
- /*
- * linux/kernel/fork.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- */
- /*
- * 'fork.c' contains the help-routines for the 'fork' system call
- * (see also entry.S and others).
- * Fork is rather simple, once you get the hang of it, but the memory
- * management can be a bitch. See 'mm/memory.c': 'copy_page_range()'
- */
- #include <linux/config.h>
- #include <linux/slab.h>
- #include <linux/init.h>
- #include <linux/unistd.h>
- #include <linux/smp_lock.h>
- #include <linux/module.h>
- #include <linux/vmalloc.h>
- #include <linux/completion.h>
- #include <linux/personality.h>
- #include <asm/pgtable.h>
- #include <asm/pgalloc.h>
- #include <asm/uaccess.h>
- #include <asm/mmu_context.h>
- /* The idle threads do not count.. */
- int nr_threads;
- int nr_running;
- int max_threads;
- unsigned long total_forks; /* Handle normal Linux uptimes. */
- int last_pid;
- struct task_struct *pidhash[PIDHASH_SZ];
- void add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
- {
- unsigned long flags;
- wait->flags &= ~WQ_FLAG_EXCLUSIVE;
- wq_write_lock_irqsave(&q->lock, flags);
- __add_wait_queue(q, wait);
- wq_write_unlock_irqrestore(&q->lock, flags);
- }
- void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)
- {
- unsigned long flags;
- wait->flags |= WQ_FLAG_EXCLUSIVE;
- wq_write_lock_irqsave(&q->lock, flags);
- __add_wait_queue_tail(q, wait);
- wq_write_unlock_irqrestore(&q->lock, flags);
- }
- void remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
- {
- unsigned long flags;
- wq_write_lock_irqsave(&q->lock, flags);
- __remove_wait_queue(q, wait);
- wq_write_unlock_irqrestore(&q->lock, flags);
- }
- void __init fork_init(unsigned long mempages)
- {
- /*
- * The default maximum number of threads is set to a safe
- * value: the thread structures can take up at most half
- * of memory.
- */
- #if THREAD_SIZE > PAGE_SIZE
- max_threads = mempages / (THREAD_SIZE/PAGE_SIZE) / 8;
- #else
- max_threads = (mempages * PAGE_SIZE) / (8 * THREAD_SIZE);
- #endif
- init_task.rlim[RLIMIT_NPROC].rlim_cur = max_threads/2;
- init_task.rlim[RLIMIT_NPROC].rlim_max = max_threads/2;
- }
- /* Protects next_safe and last_pid. */
- spinlock_t lastpid_lock = SPIN_LOCK_UNLOCKED;
- static int get_pid(unsigned long flags)
- {
- static int next_safe = PID_MAX;
- struct task_struct *p;
- int pid;
- if (flags & CLONE_PID)
- return current->pid;
- spin_lock(&lastpid_lock);
- if((++last_pid) & 0xffff8000) {
- last_pid = 300; /* Skip daemons etc. */
- goto inside;
- }
- if(last_pid >= next_safe) {
- inside:
- next_safe = PID_MAX;
- read_lock(&tasklist_lock);
- repeat:
- for_each_task(p) {
- if(p->pid == last_pid ||
- p->pgrp == last_pid ||
- p->tgid == last_pid ||
- p->session == last_pid) {
- if(++last_pid >= next_safe) {
- if(last_pid & 0xffff8000)
- last_pid = 300;
- next_safe = PID_MAX;
- }
- goto repeat;
- }
- if(p->pid > last_pid && next_safe > p->pid)
- next_safe = p->pid;
- if(p->pgrp > last_pid && next_safe > p->pgrp)
- next_safe = p->pgrp;
- if(p->session > last_pid && next_safe > p->session)
- next_safe = p->session;
- }
- read_unlock(&tasklist_lock);
- }
- pid = last_pid;
- spin_unlock(&lastpid_lock);
- return pid;
- }
- static inline int dup_mmap(struct mm_struct * mm)
- {
- struct vm_area_struct * mpnt, *tmp, **pprev;
- int retval;
- flush_cache_mm(current->mm);
- mm->locked_vm = 0;
- mm->mmap = NULL;
- mm->mmap_cache = NULL;
- mm->map_count = 0;
- mm->rss = 0;
- mm->cpu_vm_mask = 0;
- mm->swap_address = 0;
- pprev = &mm->mmap;
- /*
- * Add it to the mmlist after the parent.
- * Doing it this way means that we can order the list,
- * and fork() won't mess up the ordering significantly.
- * Add it first so that swapoff can see any swap entries.
- */
- spin_lock(&mmlist_lock);
- list_add(&mm->mmlist, ¤t->mm->mmlist);
- mmlist_nr++;
- spin_unlock(&mmlist_lock);
- for (mpnt = current->mm->mmap ; mpnt ; mpnt = mpnt->vm_next) {
- struct file *file;
- retval = -ENOMEM;
- if(mpnt->vm_flags & VM_DONTCOPY)
- continue;
- tmp = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
- if (!tmp)
- goto fail_nomem;
- *tmp = *mpnt;
- tmp->vm_flags &= ~VM_LOCKED;
- tmp->vm_mm = mm;
- tmp->vm_next = NULL;
- file = tmp->vm_file;
- if (file) {
- struct inode *inode = file->f_dentry->d_inode;
- get_file(file);
- if (tmp->vm_flags & VM_DENYWRITE)
- atomic_dec(&inode->i_writecount);
-
- /* insert tmp into the share list, just after mpnt */
- spin_lock(&inode->i_mapping->i_shared_lock);
- if((tmp->vm_next_share = mpnt->vm_next_share) != NULL)
- mpnt->vm_next_share->vm_pprev_share =
- &tmp->vm_next_share;
- mpnt->vm_next_share = tmp;
- tmp->vm_pprev_share = &mpnt->vm_next_share;
- spin_unlock(&inode->i_mapping->i_shared_lock);
- }
- /*
- * Link in the new vma and copy the page table entries:
- * link in first so that swapoff can see swap entries.
- */
- spin_lock(&mm->page_table_lock);
- *pprev = tmp;
- pprev = &tmp->vm_next;
- mm->map_count++;
- retval = copy_page_range(mm, current->mm, tmp);
- spin_unlock(&mm->page_table_lock);
- if (tmp->vm_ops && tmp->vm_ops->open)
- tmp->vm_ops->open(tmp);
- if (retval)
- goto fail_nomem;
- }
- retval = 0;
- build_mmap_rb(mm);
- fail_nomem:
- flush_tlb_mm(current->mm);
- memc_update_mm(mm);
- return retval;
- }
- spinlock_t mmlist_lock __cacheline_aligned = SPIN_LOCK_UNLOCKED;
- int mmlist_nr;
- #define allocate_mm() (kmem_cache_alloc(mm_cachep, SLAB_KERNEL))
- #define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
- static struct mm_struct * mm_init(struct mm_struct * mm)
- {
- atomic_set(&mm->mm_users, 1);
- atomic_set(&mm->mm_count, 1);
- init_rwsem(&mm->mmap_sem);
- mm->page_table_lock = SPIN_LOCK_UNLOCKED;
- mm->pgd = pgd_alloc(mm);
- mm->def_flags = 0;
- if (mm->pgd)
- return mm;
- free_mm(mm);
- return NULL;
- }
-
- /*
- * Allocate and initialize an mm_struct.
- */
- struct mm_struct * mm_alloc(void)
- {
- struct mm_struct * mm;
- mm = allocate_mm();
- if (mm) {
- memset(mm, 0, sizeof(*mm));
- return mm_init(mm);
- }
- return NULL;
- }
- /*
- * Called when the last reference to the mm
- * is dropped: either by a lazy thread or by
- * mmput. Free the page directory and the mm.
- */
- inline void __mmdrop(struct mm_struct *mm)
- {
- if (mm == &init_mm) BUG();
- pgd_free(mm->pgd);
- destroy_context(mm);
- free_mm(mm);
- }
- /*
- * Decrement the use count and release all resources for an mm.
- */
- void mmput(struct mm_struct *mm)
- {
- if (atomic_dec_and_lock(&mm->mm_users, &mmlist_lock)) {
- extern struct mm_struct *swap_mm;
- if (swap_mm == mm)
- swap_mm = list_entry(mm->mmlist.next, struct mm_struct, mmlist);
- list_del(&mm->mmlist);
- mmlist_nr--;
- spin_unlock(&mmlist_lock);
- exit_mmap(mm);
- mmdrop(mm);
- }
- }
- /* Please note the differences between mmput and mm_release.
- * mmput is called whenever we stop holding onto a mm_struct,
- * error success whatever.
- *
- * mm_release is called after a mm_struct has been removed
- * from the current process.
- *
- * This difference is important for error handling, when we
- * only half set up a mm_struct for a new process and need to restore
- * the old one. Because we mmput the new mm_struct before
- * restoring the old one. . .
- * Eric Biederman 10 January 1998
- */
- void mm_release(void)
- {
- struct task_struct *tsk = current;
- struct completion *vfork_done = tsk->vfork_done;
- /* notify parent sleeping on vfork() */
- if (vfork_done) {
- tsk->vfork_done = NULL;
- complete(vfork_done);
- }
- }
- static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
- {
- struct mm_struct * mm, *oldmm;
- int retval;
- tsk->min_flt = tsk->maj_flt = 0;
- tsk->cmin_flt = tsk->cmaj_flt = 0;
- tsk->nswap = tsk->cnswap = 0;
- tsk->mm = NULL;
- tsk->active_mm = NULL;
- /*
- * Are we cloning a kernel thread?
- *
- * We need to steal a active VM for that..
- */
- oldmm = current->mm;
- if (!oldmm)
- return 0;
- if (clone_flags & CLONE_VM) {
- atomic_inc(&oldmm->mm_users);
- mm = oldmm;
- goto good_mm;
- }
- retval = -ENOMEM;
- mm = allocate_mm();
- if (!mm)
- goto fail_nomem;
- /* Copy the current MM stuff.. */
- memcpy(mm, oldmm, sizeof(*mm));
- if (!mm_init(mm))
- goto fail_nomem;
- down_write(&oldmm->mmap_sem);
- retval = dup_mmap(mm);
- up_write(&oldmm->mmap_sem);
- if (retval)
- goto free_pt;
- /*
- * child gets a private LDT (if there was an LDT in the parent)
- */
- copy_segments(tsk, mm);
- if (init_new_context(tsk,mm))
- goto free_pt;
- good_mm:
- tsk->mm = mm;
- tsk->active_mm = mm;
- return 0;
- free_pt:
- mmput(mm);
- fail_nomem:
- return retval;
- }
- static inline struct fs_struct *__copy_fs_struct(struct fs_struct *old)
- {
- struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
- /* We don't need to lock fs - think why ;-) */
- if (fs) {
- atomic_set(&fs->count, 1);
- fs->lock = RW_LOCK_UNLOCKED;
- fs->umask = old->umask;
- read_lock(&old->lock);
- fs->rootmnt = mntget(old->rootmnt);
- fs->root = dget(old->root);
- fs->pwdmnt = mntget(old->pwdmnt);
- fs->pwd = dget(old->pwd);
- if (old->altroot) {
- fs->altrootmnt = mntget(old->altrootmnt);
- fs->altroot = dget(old->altroot);
- } else {
- fs->altrootmnt = NULL;
- fs->altroot = NULL;
- }
- read_unlock(&old->lock);
- }
- return fs;
- }
- struct fs_struct *copy_fs_struct(struct fs_struct *old)
- {
- return __copy_fs_struct(old);
- }
- static inline int copy_fs(unsigned long clone_flags, struct task_struct * tsk)
- {
- if (clone_flags & CLONE_FS) {
- atomic_inc(¤t->fs->count);
- return 0;
- }
- tsk->fs = __copy_fs_struct(current->fs);
- if (!tsk->fs)
- return -1;
- return 0;
- }
- static int count_open_files(struct files_struct *files, int size)
- {
- int i;
-
- /* Find the last open fd */
- for (i = size/(8*sizeof(long)); i > 0; ) {
- if (files->open_fds->fds_bits[--i])
- break;
- }
- i = (i+1) * 8 * sizeof(long);
- return i;
- }
- static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
- {
- struct files_struct *oldf, *newf;
- struct file **old_fds, **new_fds;
- int open_files, nfds, size, i, error = 0;
- /*
- * A background process may not have any files ...
- */
- oldf = current->files;
- if (!oldf)
- goto out;
- if (clone_flags & CLONE_FILES) {
- atomic_inc(&oldf->count);
- goto out;
- }
- tsk->files = NULL;
- error = -ENOMEM;
- newf = kmem_cache_alloc(files_cachep, SLAB_KERNEL);
- if (!newf)
- goto out;
- atomic_set(&newf->count, 1);
- newf->file_lock = RW_LOCK_UNLOCKED;
- newf->next_fd = 0;
- newf->max_fds = NR_OPEN_DEFAULT;
- newf->max_fdset = __FD_SETSIZE;
- newf->close_on_exec = &newf->close_on_exec_init;
- newf->open_fds = &newf->open_fds_init;
- newf->fd = &newf->fd_array[0];
- /* We don't yet have the oldf readlock, but even if the old
- fdset gets grown now, we'll only copy up to "size" fds */
- size = oldf->max_fdset;
- if (size > __FD_SETSIZE) {
- newf->max_fdset = 0;
- write_lock(&newf->file_lock);
- error = expand_fdset(newf, size-1);
- write_unlock(&newf->file_lock);
- if (error)
- goto out_release;
- }
- read_lock(&oldf->file_lock);
- open_files = count_open_files(oldf, size);
- /*
- * Check whether we need to allocate a larger fd array.
- * Note: we're not a clone task, so the open count won't
- * change.
- */
- nfds = NR_OPEN_DEFAULT;
- if (open_files > nfds) {
- read_unlock(&oldf->file_lock);
- newf->max_fds = 0;
- write_lock(&newf->file_lock);
- error = expand_fd_array(newf, open_files-1);
- write_unlock(&newf->file_lock);
- if (error)
- goto out_release;
- nfds = newf->max_fds;
- read_lock(&oldf->file_lock);
- }
- old_fds = oldf->fd;
- new_fds = newf->fd;
- memcpy(newf->open_fds->fds_bits, oldf->open_fds->fds_bits, open_files/8);
- memcpy(newf->close_on_exec->fds_bits, oldf->close_on_exec->fds_bits, open_files/8);
- for (i = open_files; i != 0; i--) {
- struct file *f = *old_fds++;
- if (f)
- get_file(f);
- *new_fds++ = f;
- }
- read_unlock(&oldf->file_lock);
- /* compute the remainder to be cleared */
- size = (newf->max_fds - open_files) * sizeof(struct file *);
- /* This is long word aligned thus could use a optimized version */
- memset(new_fds, 0, size);
- if (newf->max_fdset > open_files) {
- int left = (newf->max_fdset-open_files)/8;
- int start = open_files / (8 * sizeof(unsigned long));
-
- memset(&newf->open_fds->fds_bits[start], 0, left);
- memset(&newf->close_on_exec->fds_bits[start], 0, left);
- }
- tsk->files = newf;
- error = 0;
- out:
- return error;
- out_release:
- free_fdset (newf->close_on_exec, newf->max_fdset);
- free_fdset (newf->open_fds, newf->max_fdset);
- kmem_cache_free(files_cachep, newf);
- goto out;
- }
- static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
- {
- struct signal_struct *sig;
- if (clone_flags & CLONE_SIGHAND) {
- atomic_inc(¤t->sig->count);
- return 0;
- }
- sig = kmem_cache_alloc(sigact_cachep, GFP_KERNEL);
- tsk->sig = sig;
- if (!sig)
- return -1;
- spin_lock_init(&sig->siglock);
- atomic_set(&sig->count, 1);
- memcpy(tsk->sig->action, current->sig->action, sizeof(tsk->sig->action));
- return 0;
- }
- static inline void copy_flags(unsigned long clone_flags, struct task_struct *p)
- {
- unsigned long new_flags = p->flags;
- new_flags &= ~(PF_SUPERPRIV | PF_USEDFPU);
- new_flags |= PF_FORKNOEXEC;
- if (!(clone_flags & CLONE_PTRACE))
- p->ptrace = 0;
- p->flags = new_flags;
- }
- /*
- * Ok, this is the main fork-routine. It copies the system process
- * information (task[nr]) and sets up the necessary registers. It also
- * copies the data segment in its entirety. The "stack_start" and
- * "stack_top" arguments are simply passed along to the platform
- * specific copy_thread() routine. Most platforms ignore stack_top.
- * For an example that's using stack_top, see
- * arch/ia64/kernel/process.c.
- */
- int do_fork(unsigned long clone_flags, unsigned long stack_start,
- struct pt_regs *regs, unsigned long stack_size)
- {
- int retval;
- struct task_struct *p;
- struct completion vfork;
- retval = -EPERM;
- /*
- * CLONE_PID is only allowed for the initial SMP swapper
- * calls
- */
- if (clone_flags & CLONE_PID) {
- if (current->pid)
- goto fork_out;
- }
- retval = -ENOMEM;
- p = alloc_task_struct();
- if (!p)
- goto fork_out;
- *p = *current;
- retval = -EAGAIN;
- /*
- * Check if we are over our maximum process limit, but be sure to
- * exclude root. This is needed to make it possible for login and
- * friends to set the per-user process limit to something lower
- * than the amount of processes root is running. -- Rik
- */
- if (atomic_read(&p->user->processes) >= p->rlim[RLIMIT_NPROC].rlim_cur
- && !capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE))
- goto bad_fork_free;
- atomic_inc(&p->user->__count);
- atomic_inc(&p->user->processes);
- /*
- * Counter increases are protected by
- * the kernel lock so nr_threads can't
- * increase under us (but it may decrease).
- */
- if (nr_threads >= max_threads)
- goto bad_fork_cleanup_count;
-
- get_exec_domain(p->exec_domain);
- if (p->binfmt && p->binfmt->module)
- __MOD_INC_USE_COUNT(p->binfmt->module);
- p->did_exec = 0;
- p->swappable = 0;
- p->state = TASK_UNINTERRUPTIBLE;
- copy_flags(clone_flags, p);
- p->pid = get_pid(clone_flags);
- p->run_list.next = NULL;
- p->run_list.prev = NULL;
- p->p_cptr = NULL;
- init_waitqueue_head(&p->wait_chldexit);
- p->vfork_done = NULL;
- if (clone_flags & CLONE_VFORK) {
- p->vfork_done = &vfork;
- init_completion(&vfork);
- }
- spin_lock_init(&p->alloc_lock);
- p->sigpending = 0;
- init_sigpending(&p->pending);
- p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
- p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
- init_timer(&p->real_timer);
- p->real_timer.data = (unsigned long) p;
- p->leader = 0; /* session leadership doesn't inherit */
- p->tty_old_pgrp = 0;
- p->times.tms_utime = p->times.tms_stime = 0;
- p->times.tms_cutime = p->times.tms_cstime = 0;
- #ifdef CONFIG_SMP
- {
- int i;
- p->cpus_runnable = ~0UL;
- p->processor = current->processor;
- /* ?? should we just memset this ?? */
- for(i = 0; i < smp_num_cpus; i++)
- p->per_cpu_utime[i] = p->per_cpu_stime[i] = 0;
- spin_lock_init(&p->sigmask_lock);
- }
- #endif
- p->lock_depth = -1; /* -1 = no lock */
- p->start_time = jiffies;
- INIT_LIST_HEAD(&p->local_pages);
- retval = -ENOMEM;
- /* copy all the process information */
- if (copy_files(clone_flags, p))
- goto bad_fork_cleanup;
- if (copy_fs(clone_flags, p))
- goto bad_fork_cleanup_files;
- if (copy_sighand(clone_flags, p))
- goto bad_fork_cleanup_fs;
- if (copy_mm(clone_flags, p))
- goto bad_fork_cleanup_sighand;
- retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
- if (retval)
- goto bad_fork_cleanup_mm;
- p->semundo = NULL;
-
- /* Our parent execution domain becomes current domain
- These must match for thread signalling to apply */
-
- p->parent_exec_id = p->self_exec_id;
- /* ok, now we should be set up.. */
- p->swappable = 1;
- p->exit_signal = clone_flags & CSIGNAL;
- p->pdeath_signal = 0;
- /*
- * "share" dynamic priority between parent and child, thus the
- * total amount of dynamic priorities in the system doesnt change,
- * more scheduling fairness. This is only important in the first
- * timeslice, on the long run the scheduling behaviour is unchanged.
- */
- p->counter = (current->counter + 1) >> 1;
- current->counter >>= 1;
- if (!current->counter)
- current->need_resched = 1;
- /*
- * Ok, add it to the run-queues and make it
- * visible to the rest of the system.
- *
- * Let it rip!
- */
- retval = p->pid;
- p->tgid = retval;
- INIT_LIST_HEAD(&p->thread_group);
- /* Need tasklist lock for parent etc handling! */
- write_lock_irq(&tasklist_lock);
- /* CLONE_PARENT and CLONE_THREAD re-use the old parent */
- p->p_opptr = current->p_opptr;
- p->p_pptr = current->p_pptr;
- if (!(clone_flags & (CLONE_PARENT | CLONE_THREAD))) {
- p->p_opptr = current;
- if (!(p->ptrace & PT_PTRACED))
- p->p_pptr = current;
- }
- if (clone_flags & CLONE_THREAD) {
- p->tgid = current->tgid;
- list_add(&p->thread_group, ¤t->thread_group);
- }
- SET_LINKS(p);
- hash_pid(p);
- nr_threads++;
- write_unlock_irq(&tasklist_lock);
- if (p->ptrace & PT_PTRACED)
- send_sig(SIGSTOP, p, 1);
- wake_up_process(p); /* do this last */
- ++total_forks;
- if (clone_flags & CLONE_VFORK)
- wait_for_completion(&vfork);
- fork_out:
- return retval;
- bad_fork_cleanup_mm:
- exit_mm(p);
- bad_fork_cleanup_sighand:
- exit_sighand(p);
- bad_fork_cleanup_fs:
- exit_fs(p); /* blocking */
- bad_fork_cleanup_files:
- exit_files(p); /* blocking */
- bad_fork_cleanup:
- put_exec_domain(p->exec_domain);
- if (p->binfmt && p->binfmt->module)
- __MOD_DEC_USE_COUNT(p->binfmt->module);
- bad_fork_cleanup_count:
- atomic_dec(&p->user->processes);
- free_uid(p->user);
- bad_fork_free:
- free_task_struct(p);
- goto fork_out;
- }
- /* SLAB cache for signal_struct structures (tsk->sig) */
- kmem_cache_t *sigact_cachep;
- /* SLAB cache for files_struct structures (tsk->files) */
- kmem_cache_t *files_cachep;
- /* SLAB cache for fs_struct structures (tsk->fs) */
- kmem_cache_t *fs_cachep;
- /* SLAB cache for vm_area_struct structures */
- kmem_cache_t *vm_area_cachep;
- /* SLAB cache for mm_struct structures (tsk->mm) */
- kmem_cache_t *mm_cachep;
- void __init proc_caches_init(void)
- {
- sigact_cachep = kmem_cache_create("signal_act",
- sizeof(struct signal_struct), 0,
- SLAB_HWCACHE_ALIGN, NULL, NULL);
- if (!sigact_cachep)
- panic("Cannot create signal action SLAB cache");
- files_cachep = kmem_cache_create("files_cache",
- sizeof(struct files_struct), 0,
- SLAB_HWCACHE_ALIGN, NULL, NULL);
- if (!files_cachep)
- panic("Cannot create files SLAB cache");
- fs_cachep = kmem_cache_create("fs_cache",
- sizeof(struct fs_struct), 0,
- SLAB_HWCACHE_ALIGN, NULL, NULL);
- if (!fs_cachep)
- panic("Cannot create fs_struct SLAB cache");
-
- vm_area_cachep = kmem_cache_create("vm_area_struct",
- sizeof(struct vm_area_struct), 0,
- SLAB_HWCACHE_ALIGN, NULL, NULL);
- if(!vm_area_cachep)
- panic("vma_init: Cannot alloc vm_area_struct SLAB cache");
- mm_cachep = kmem_cache_create("mm_struct",
- sizeof(struct mm_struct), 0,
- SLAB_HWCACHE_ALIGN, NULL, NULL);
- if(!mm_cachep)
- panic("vma_init: Cannot alloc mm_struct SLAB cache");
- }