If a realtime task does not explicitly set an ioprio make it inherit the realtime class and a priority dependant on its realtime priority. Signed-off-by: Con Kolivas --- block/cfq-iosched.c | 4 ++-- include/linux/ioprio.h | 13 ++++++++++++- 2 files changed, 14 insertions(+), 3 deletions(-) Index: linux-2.6.22-rc4-ck1/block/cfq-iosched.c =================================================================== --- linux-2.6.22-rc4-ck1.orig/block/cfq-iosched.c 2007-06-10 21:58:52.000000000 +1000 +++ linux-2.6.22-rc4-ck1/block/cfq-iosched.c 2007-06-10 21:59:55.000000000 +1000 @@ -1276,10 +1276,10 @@ static void cfq_init_prio_data(struct cf printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); case IOPRIO_CLASS_NONE: /* - * no prio set, place us in the middle of the BE classes + * Select class and ioprio according to policy and nice */ + cfqq->ioprio_class = task_policy_ioprio_class(tsk); cfqq->ioprio = task_nice_ioprio(tsk); - cfqq->ioprio_class = IOPRIO_CLASS_BE; break; case IOPRIO_CLASS_RT: cfqq->ioprio = task_ioprio(tsk); Index: linux-2.6.22-rc4-ck1/include/linux/ioprio.h =================================================================== --- linux-2.6.22-rc4-ck1.orig/include/linux/ioprio.h 2007-06-10 21:58:52.000000000 +1000 +++ linux-2.6.22-rc4-ck1/include/linux/ioprio.h 2007-06-10 21:59:55.000000000 +1000 @@ -22,7 +22,7 @@ * class, the default for any process. IDLE is the idle scheduling class, it * is only served when no one else is using the disk. */ -enum { +enum ioprio_class { IOPRIO_CLASS_NONE, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, @@ -51,8 +51,19 @@ static inline int task_ioprio(struct tas return IOPRIO_PRIO_DATA(task->ioprio); } +static inline enum ioprio_class + task_policy_ioprio_class(struct task_struct *task) +{ + if (rt_task(task)) + return IOPRIO_CLASS_RT; + return IOPRIO_CLASS_BE; +} + static inline int task_nice_ioprio(struct task_struct *task) { + if (rt_task(task)) + return (MAX_RT_PRIO - task->rt_priority) * IOPRIO_BE_NR / + (MAX_RT_PRIO + 1); return (task_nice(task) + 20) / 5; }