[PATCH] Update cfq io scheduler to time sliced design

This updates the CFQ io scheduler to the new time sliced design (cfq
v3).  It provides full process fairness, while giving excellent
aggregate system throughput even for many competing processes.  It
supports io priorities, either inherited from the cpu nice value or set
directly with the ioprio_get/set syscalls.  The latter closely mimic
set/getpriority.

This import is based on my latest from -mm.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 7 insertions, 8 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 3ebcd60a19c6..9d1b10ed0135 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -784,6 +784,8 @@ fastcall NORET_TYPE void do_exit(long code)
 
         profile_task_exit(tsk);
 
+        WARN_ON(atomic_read(&tsk->fs_excl));
+
         if (unlikely(in_interrupt()))
                 panic("Aiee, killing interrupt handler!");
         if (unlikely(!tsk->pid))
diff --git a/kernel/fork.c b/kernel/fork.c
index 2c7806873bfd..cdef6cea8900 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1090,6 +1090,11 @@ static task_t *copy_process(unsigned long clone_flags,
                 spin_unlock(&current->sighand->siglock);
         }
 
+        /*
+         * inherit ioprio
+         */
+        p->ioprio = current->ioprio;
+
         SET_LINKS(p);
         if (unlikely(p->ptrace & PT_PTRACED))
                 __ptrace_link(p, current->parent);
diff --git a/kernel/sched.c b/kernel/sched.c
index a07cff90d849..e2b0d3e4dd06 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3448,15 +3448,7 @@ int task_nice(const task_t *p)
 {
         return TASK_NICE(p);
 }
-
-/*
- * The only users of task_nice are binfmt_elf and binfmt_elf32.
- * binfmt_elf is no longer modular, but binfmt_elf32 still is.
- * Therefore, task_nice is needed if there is a compat_mode.
- */
-#ifdef CONFIG_COMPAT
 EXPORT_SYMBOL_GPL(task_nice);
-#endif
 
 /**
  * idle_cpu - is a given cpu idle currently?