diff options
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 15 | ||||
| -rw-r--r-- | kernel/sysctl.c | 8 |
3 files changed, 21 insertions, 4 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 0fcbf34a4f73..00081d84169f 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -358,6 +358,7 @@ struct file; struct perf_mmap_data { struct rcu_head rcu_head; int nr_pages; /* nr of data pages */ + int nr_locked; /* nr pages mlocked */ atomic_t poll; /* POLL_ for wakeups */ atomic_t head; /* write position */ @@ -575,6 +576,7 @@ struct perf_callchain_entry { extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs); extern int sysctl_perf_counter_priv; +extern int sysctl_perf_counter_mlock; extern void perf_counter_init(void); diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 6e6834e0587e..2d1342738305 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -44,6 +44,7 @@ static atomic_t nr_munmap_tracking __read_mostly; static atomic_t nr_comm_tracking __read_mostly; int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */ +int sysctl_perf_counter_mlock __read_mostly = 128; /* 'free' kb per counter */ /* * Lock for (sysadmin-configurable) counter reservations: @@ -1461,7 +1462,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) if (atomic_dec_and_mutex_lock(&counter->mmap_count, &counter->mmap_mutex)) { - vma->vm_mm->locked_vm -= counter->data->nr_pages + 1; + vma->vm_mm->locked_vm -= counter->data->nr_locked; perf_mmap_data_free(counter); mutex_unlock(&counter->mmap_mutex); } @@ -1480,6 +1481,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) unsigned long nr_pages; unsigned long locked, lock_limit; int ret = 0; + long extra; if (!(vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_WRITE)) return -EINVAL; @@ -1507,8 +1509,12 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) goto unlock; } - locked = vma->vm_mm->locked_vm; - locked += nr_pages + 1; + extra = nr_pages /* + 1 only account the data pages */; + extra -= sysctl_perf_counter_mlock >> (PAGE_SHIFT - 10); + if (extra < 0) + extra = 0; + + locked = vma->vm_mm->locked_vm + extra; lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; lock_limit >>= PAGE_SHIFT; @@ -1524,7 +1530,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) goto unlock; atomic_set(&counter->mmap_count, 1); - vma->vm_mm->locked_vm += nr_pages + 1; + vma->vm_mm->locked_vm += extra; + counter->data->nr_locked = extra; unlock: mutex_unlock(&counter->mmap_mutex); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8203d70928d5..3b05c2b088d2 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -920,6 +920,14 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "perf_counter_mlock_kb", + .data = &sysctl_perf_counter_mlock, + .maxlen = sizeof(sysctl_perf_counter_mlock), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, #endif /* * NOTE: do not add new entries to this table unless you have read |