[PATCH] sched: TASK_NONINTERACTIVE

This patch implements a task state bit (TASK_NONINTERACTIVE), which can be
used by blocking points to mark the task's wait as "non-interactive".  This
does not mean the task will be considered a CPU-hog - the wait will simply
not have an effect on the waiting task's priority - positive or negative
alike.  Right now only pipe_wait() will make use of it, because it's a
common source of not-so-interactive waits (kernel compilation jobs, etc.).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index 2c7a23dde2d8..66aa0b938d6a 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -39,7 +39,11 @@ void pipe_wait(struct inode * inode)
 {
         DEFINE_WAIT(wait);
 
-        prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE);
+        /*
+         * Pipes are system-local resources, so sleeping on them
+         * is considered a noninteractive wait:
+         */
+        prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);
         up(PIPE_SEM(*inode));
         schedule();
         finish_wait(PIPE_WAIT(*inode), &wait);