UBUNTU: Ubuntu-2.6.38-12.51

[linux-flexiantxendom0-natty.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 856eac3..c85d59e 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -65,6 +65,8 @@
 #include <linux/perf_event.h>
 #include <linux/posix-timers.h>
 #include <linux/user-return-notifier.h>
+#include <linux/oom.h>
+#include <linux/khugepaged.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -168,6 +170,7 @@ EXPORT_SYMBOL(free_task);
 static inline void free_signal_struct(struct signal_struct *sig)
 {
        taskstats_tgid_free(sig);
+       sched_autogroup_exit(sig);
        kmem_cache_free(signal_cachep, sig);
 }
 
@@ -183,6 +186,7 @@ void __put_task_struct(struct task_struct *tsk)
        WARN_ON(atomic_read(&tsk->usage));
        WARN_ON(tsk == current);
 
+       security_task_free(tsk);
        exit_creds(tsk);
        delayacct_tsk_free(tsk);
        put_signal_struct(tsk->signal);
@@ -272,6 +276,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 
        setup_thread_stack(tsk, orig);
        clear_user_return_notifier(tsk);
+       clear_tsk_need_resched(tsk);
        stackend = end_of_stack(tsk);
        *stackend = STACK_END_MAGIC;    /* for overflow detection */
 
@@ -300,7 +305,7 @@ out:
 #ifdef CONFIG_MMU
 static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 {
-       struct vm_area_struct *mpnt, *tmp, **pprev;
+       struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
        struct rb_node **rb_link, *rb_parent;
        int retval;
        unsigned long charge;
@@ -327,7 +332,11 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
        retval = ksm_fork(mm, oldmm);
        if (retval)
                goto out;
+       retval = khugepaged_fork(mm, oldmm);
+       if (retval)
+               goto out;
 
+       prev = NULL;
        for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
                struct file *file;
 
@@ -355,11 +364,11 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                if (IS_ERR(pol))
                        goto fail_nomem_policy;
                vma_set_policy(tmp, pol);
+               tmp->vm_mm = mm;
                if (anon_vma_fork(tmp, mpnt))
                        goto fail_nomem_anon_vma_fork;
                tmp->vm_flags &= ~VM_LOCKED;
-               tmp->vm_mm = mm;
-               tmp->vm_next = NULL;
+               tmp->vm_next = tmp->vm_prev = NULL;
                file = tmp->vm_file;
                if (file) {
                        struct inode *inode = file->f_path.dentry->d_inode;
@@ -392,6 +401,8 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                 */
                *pprev = tmp;
                pprev = &tmp->vm_next;
+               tmp->vm_prev = prev;
+               prev = tmp;
 
                __vma_link_rb(mm, tmp, rb_link, rb_parent);
                rb_link = &tmp->vm_rb.rb_right;
@@ -485,6 +496,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
        mm->cached_hole_size = ~0UL;
        mm_init_aio(mm);
        mm_init_owner(mm, p);
+       atomic_set(&mm->oom_disable_count, 0);
 
        if (likely(!mm_alloc_pgd(mm))) {
                mm->def_flags = 0;
@@ -522,6 +534,9 @@ void __mmdrop(struct mm_struct *mm)
        mm_free_pgd(mm);
        destroy_context(mm);
        mmu_notifier_mm_destroy(mm);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       VM_BUG_ON(mm->pmd_huge_pte);
+#endif
        free_mm(mm);
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
@@ -536,6 +551,7 @@ void mmput(struct mm_struct *mm)
        if (atomic_dec_and_test(&mm->mm_users)) {
                exit_aio(mm);
                ksm_exit(mm);
+               khugepaged_exit(mm); /* must run before exit_mmap */
                exit_mmap(mm);
                set_mm_exe_file(mm, NULL);
                if (!list_empty(&mm->mmlist)) {
@@ -662,6 +678,10 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
        mm->token_priority = 0;
        mm->last_interval = 0;
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       mm->pmd_huge_pte = NULL;
+#endif
+
        if (!mm_init(mm, tsk))
                goto fail_nomem;
 
@@ -738,6 +758,8 @@ good_mm:
        /* Initializing for Swap token stuff */
        mm->token_priority = 0;
        mm->last_interval = 0;
+       if (tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+               atomic_inc(&mm->oom_disable_count);
 
        tsk->mm = mm;
        tsk->active_mm = mm;
@@ -897,9 +919,13 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        posix_cpu_timers_init_group(sig);
 
        tty_audit_fork(sig);
+       sched_autogroup_fork(sig);
 
        sig->oom_adj = current->signal->oom_adj;
        sig->oom_score_adj = current->signal->oom_score_adj;
+       sig->oom_score_adj_min = current->signal->oom_score_adj_min;
+
+       mutex_init(&sig->cred_guard_mutex);
 
        return 0;
 }
@@ -1273,7 +1299,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                        attach_pid(p, PIDTYPE_SID, task_session(current));
                        list_add_tail(&p->sibling, &p->real_parent->children);
                        list_add_tail_rcu(&p->tasks, &init_task.tasks);
-                       __get_cpu_var(process_counts)++;
+                       __this_cpu_inc(process_counts);
                }
                attach_pid(p, PIDTYPE_PID, pid);
                nr_threads++;
@@ -1296,8 +1322,13 @@ bad_fork_cleanup_io:
 bad_fork_cleanup_namespaces:
        exit_task_namespaces(p);
 bad_fork_cleanup_mm:
-       if (p->mm)
+       if (p->mm) {
+               task_lock(p);
+               if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+                       atomic_dec(&p->mm->oom_disable_count);
+               task_unlock(p);
                mmput(p->mm);
+       }
 bad_fork_cleanup_signal:
        if (!(clone_flags & CLONE_THREAD))
                free_signal_struct(p->signal);
@@ -1393,23 +1424,6 @@ long do_fork(unsigned long clone_flags,
        }
 
        /*
-        * We hope to recycle these flags after 2.6.26
-        */
-       if (unlikely(clone_flags & CLONE_STOPPED)) {
-               static int __read_mostly count = 100;
-
-               if (count > 0 && printk_ratelimit()) {
-                       char comm[TASK_COMM_LEN];
-
-                       count--;
-                       printk(KERN_INFO "fork(): process `%s' used deprecated "
-                                       "clone flags 0x%lx\n",
-                               get_task_comm(comm, current),
-                               clone_flags & CLONE_STOPPED);
-               }
-       }
-
-       /*
         * When called from kernel_thread, don't do user tracing stuff.
         */
        if (likely(user_mode(regs)))
@@ -1447,16 +1461,7 @@ long do_fork(unsigned long clone_flags,
                 */
                p->flags &= ~PF_STARTING;
 
-               if (unlikely(clone_flags & CLONE_STOPPED)) {
-                       /*
-                        * We'll start up with an immediate SIGSTOP.
-                        */
-                       sigaddset(&p->pending.signal, SIGSTOP);
-                       set_tsk_thread_flag(p, TIF_SIGPENDING);
-                       __set_task_state(p, TASK_STOPPED);
-               } else {
-                       wake_up_new_task(p, clone_flags);
-               }
+               wake_up_new_task(p, clone_flags);
 
                tracehook_report_clone_complete(trace, regs,
                                                clone_flags, nr, p);
@@ -1690,6 +1695,10 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
                        active_mm = current->active_mm;
                        current->mm = new_mm;
                        current->active_mm = new_mm;
+                       if (current->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+                               atomic_dec(&mm->oom_disable_count);
+                               atomic_inc(&new_mm->oom_disable_count);
+                       }
                        activate_mm(active_mm, new_mm);
                        new_mm = mm;
                }