From: William Lee Irwin III <wli@holomorphy.com>
Remove spurious BKL acquisitions in /proc/. The BKL is not required to
access nr_threads for reporting, and get_locks_status() takes it
internally, wrapping all operations with it.
fs/proc/proc_misc.c | 9 ++++-----
fs/proc/root.c | 10 ++++++----
2 files changed, 10 insertions(+), 9 deletions(-)
diff -puN fs/proc/proc_misc.c~proc-lock_kernel-removal fs/proc/proc_misc.c
--- 25/fs/proc/proc_misc.c~proc-lock_kernel-removal 2003-06-28 02:04:31.000000000 -0700
+++ 25-akpm/fs/proc/proc_misc.c 2003-06-28 02:04:31.000000000 -0700
@@ -509,11 +509,10 @@ static int ds1286_read_proc(char *page,
static int locks_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
- int len;
- lock_kernel();
- len = get_locks_status(page, start, off, count);
- unlock_kernel();
- if (len < count) *eof = 1;
+ int len = get_locks_status(page, start, off, count);
+
+ if (len < count)
+ *eof = 1;
return len;
}
diff -puN fs/proc/root.c~proc-lock_kernel-removal fs/proc/root.c
--- 25/fs/proc/root.c~proc-lock_kernel-removal 2003-06-28 02:04:31.000000000 -0700
+++ 25-akpm/fs/proc/root.c 2003-06-28 02:04:31.000000000 -0700
@@ -81,11 +81,13 @@ void __init proc_root_init(void)
static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry)
{
- if (dir->i_ino == PROC_ROOT_INO) { /* check for safety... */
- lock_kernel();
+ /*
+ * nr_threads is actually protected by the tasklist_lock;
+ * however, it's conventional to do reads, especially for
+ * reporting, without any locking whatsoever.
+ */
+ if (dir->i_ino == PROC_ROOT_INO) /* check for safety... */
dir->i_nlink = proc_root.nlink + nr_threads;
- unlock_kernel();
- }
if (!proc_lookup(dir, dentry)) {
return NULL;
_