From b835996f628eadb55c5fb222ba46fe9395bf73c7 Mon Sep 17 00:00:00 2001 From: Dipankar Sarma Date: Fri, 9 Sep 2005 13:04:14 -0700 Subject: [PATCH] files: lock-free fd look-up With the use of RCU in files structure, the look-up of files using fds can now be lock-free. The lookup is protected by rcu_read_lock()/rcu_read_unlock(). This patch changes the readers to use lock-free lookup. Signed-off-by: Maneesh Soni Signed-off-by: Ravikiran Thirumalai Signed-off-by: Dipankar Sarma Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/tty_io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 0bfc7af68917..e5953f3433f3 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -2480,7 +2480,7 @@ static void __do_SAK(void *arg) } task_lock(p); if (p->files) { - spin_lock(&p->files->file_lock); + rcu_read_lock(); fdt = files_fdtable(p->files); for (i=0; i < fdt->max_fds; i++) { filp = fcheck_files(p->files, i); @@ -2495,7 +2495,7 @@ static void __do_SAK(void *arg) break; } } - spin_unlock(&p->files->file_lock); + rcu_read_unlock(); } task_unlock(p); } while_each_task_pid(session, PIDTYPE_SID, p); -- cgit v1.2.2