On Thu, 01 Jun 2006 11:30:33 +0200
Mike Galbraith <[email protected]> wrote:
> On Thu, 2006-06-01 at 01:48 -0700, Andrew Morton wrote:
> > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.17-rc5/2.6.17-rc5-mm2/
> >
> >
> > - A cfq bug was fixed in mainline, so the git-cfq tree has been restored.
>
> I put the fix for slab corruption into mm1, and it did indeed cure that.
> However, if I add git-cfq.patch, my box still explodes.
OK, thanks. I put a revert patch into the hot-fixes directory.
--- devel/block/cfq-iosched.c~revert-git-cfq 2006-06-01 02:46:39.000000000 -0700
+++ devel-akpm/block/cfq-iosched.c 2006-06-01 02:46:39.000000000 -0700
@@ -103,9 +103,8 @@ struct cfq_data {
* rr list of queues with requests and the count of them
*/
struct list_head rr_list[CFQ_PRIO_LISTS];
+ struct list_head busy_rr;
struct list_head cur_rr;
- unsigned short cur_prio;
-
struct list_head idle_rr;
unsigned int busy_queues;
@@ -141,6 +140,7 @@ struct cfq_data {
struct cfq_queue *active_queue;
struct cfq_io_context *active_cic;
+ int cur_prio, cur_end_prio;
unsigned int dispatch_slice;
struct timer_list idle_class_timer;
@@ -199,13 +199,8 @@ struct cfq_queue {
int on_dispatch[2];
/* io prio of this group */
- unsigned short ioprio_class, ioprio;
-
- /* current dynamic stair priority */
- unsigned short dyn_ioprio;
-
- /* same as real ioprio, except if queue has been elevated */
- unsigned short org_ioprio_class, org_ioprio;
+ unsigned short ioprio, org_ioprio;
+ unsigned short ioprio_class, org_ioprio_class;
/* various state flags, see below */
unsigned int flags;
@@ -484,13 +479,25 @@ static void cfq_resort_rr_list(struct cf
list = &cfqd->cur_rr;
else if (cfq_class_idle(cfqq))
list = &cfqd->idle_rr;
- else
- list = &cfqd->rr_list[cfqq->dyn_ioprio];
+ else {
+ /*
+ * if cfqq has requests in flight, don't allow it to be
+ * found in cfq_set_active_queue before it has finished them.
+ * this is done to increase fairness between a process that
+ * has lots of io pending vs one that only generates one
+ * sporadically or synchronously
+ */
+ if (cfq_cfqq_dispatched(cfqq))
+ list = &cfqd->busy_rr;
+ else
+ list = &cfqd->rr_list[cfqq->ioprio];
+ }
/*
- * if queue was preempted, just add to front to be fair.
+ * if queue was preempted, just add to front to be fair. busy_rr
+ * isn't sorted.
*/
- if (preempted) {
+ if (preempted || list == &cfqd->busy_rr) {
list_add(&cfqq->cfq_list, list);
return;
}
@@ -502,8 +509,6 @@ static void cfq_resort_rr_list(struct cf
while ((entry = entry->prev) != list) {
struct cfq_queue *__cfqq = list_entry_cfqq(entry);
- if (__cfqq->ioprio < cfqq->ioprio)
- break;
if (!__cfqq->service_last)
break;
if (time_before(__cfqq->service_last, cfqq->service_last))
@@ -729,49 +734,23 @@ cfq_merged_requests(request_queue_t *q,
cfq_remove_request(next);
}
-/*
- * Scale schedule slice based on io priority. Use the sync time slice only
- * if a queue is marked sync and has sync io queued. A sync queue with async
- * io only, should not get full sync slice length.
- */
-static inline int
-cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
-{
- const int base_slice = cfqd->cfq_slice[cfq_cfqq_sync(cfqq)];
- unsigned short prio = cfqq->dyn_ioprio;
-
- WARN_ON(prio >= IOPRIO_BE_NR);
-
- if (cfq_class_rt(cfqq))
- prio = 0;
-
- return base_slice + (base_slice / CFQ_SLICE_SCALE * (4 - prio));
-}
-
static inline void
-cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
-{
- cfqq->slice_end = cfq_prio_to_slice(cfqd, cfqq) + jiffies;
-}
-
-static inline int
-cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
- const int base_rq = cfqd->cfq_slice_async_rq;
- unsigned short prio = cfqq->dyn_ioprio;
-
- WARN_ON(cfqq->dyn_ioprio >= IOPRIO_BE_NR);
-
- if (cfq_class_rt(cfqq))
- prio = 0;
+ if (cfqq) {
+ /*
+ * stop potential idle class queues waiting service
+ */
+ del_timer(&cfqd->idle_class_timer);
- return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - prio));
-}
+ cfqq->slice_start = jiffies;
+ cfqq->slice_end = 0;
+ cfqq->slice_left = 0;
+ cfq_clear_cfqq_must_alloc_slice(cfqq);
+ cfq_clear_cfqq_fifo_expire(cfqq);
+ }
-static inline void cfq_prio_inc(unsigned short *p, unsigned int low_p)
-{
- if (++(*p) == CFQ_PRIO_LISTS)
- *p = low_p;
+ cfqd->active_queue = cfqq;
}
/*
@@ -803,8 +782,6 @@ __cfq_slice_expired(struct cfq_data *cfq
else
cfqq->slice_left = 0;
- cfq_prio_inc(&cfqq->dyn_ioprio, cfqq->ioprio);
-
if (cfq_cfqq_on_rr(cfqq))
cfq_resort_rr_list(cfqq, preempted);
@@ -827,58 +804,73 @@ static inline void cfq_slice_expired(str
__cfq_slice_expired(cfqd, cfqq, preempted);
}
-static struct cfq_queue *cfq_get_next_cfqq(struct cfq_data *cfqd)
+/*
+ * 0
+ * 0,1
+ * 0,1,2
+ * 0,1,2,3
+ * 0,1,2,3,4
+ * 0,1,2,3,4,5
+ * 0,1,2,3,4,5,6
+ * 0,1,2,3,4,5,6,7
+ */
+static int cfq_get_next_prio_level(struct cfq_data *cfqd)
{
- if (!cfqd->busy_queues)
- return NULL;
-
- if (list_empty(&cfqd->cur_rr)) {
- unsigned short prio = cfqd->cur_prio;
+ int prio, wrap;
- do {
- struct list_head *list = &cfqd->rr_list[prio];
+ prio = -1;
+ wrap = 0;
+ do {
+ int p;
- if (!list_empty(list)) {
- list_splice_init(list, &cfqd->cur_rr);
+ for (p = cfqd->cur_prio; p <= cfqd->cur_end_prio; p++) {
+ if (!list_empty(&cfqd->rr_list[p])) {
+ prio = p;
break;
}
+ }
- cfq_prio_inc(&prio, 0);
- } while (prio != cfqd->cur_prio);
+ if (prio != -1)
+ break;
+ cfqd->cur_prio = 0;
+ if (++cfqd->cur_end_prio == CFQ_PRIO_LISTS) {
+ cfqd->cur_end_prio = 0;
+ if (wrap)
+ break;
+ wrap = 1;
+ }
+ } while (1);
- cfq_prio_inc(&cfqd->cur_prio, 0);
- }
+ if (unlikely(prio == -1))
+ return -1;
- if (!list_empty(&cfqd->cur_rr));
- return list_entry_cfqq(cfqd->cur_rr.next);
+ BUG_ON(prio >= CFQ_PRIO_LISTS);
- return NULL;
-}
+ list_splice_init(&cfqd->rr_list[prio], &cfqd->cur_rr);
-static inline void
-__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
-{
- if (cfqq) {
- WARN_ON(RB_EMPTY(&cfqq->sort_list));
-
- /*
- * stop potential idle class queues waiting service
- */
- del_timer(&cfqd->idle_class_timer);
-
- cfqq->slice_start = jiffies;
- cfqq->slice_end = 0;
- cfqq->slice_left = 0;
- cfq_clear_cfqq_must_alloc_slice(cfqq);
- cfq_clear_cfqq_fifo_expire(cfqq);
+ cfqd->cur_prio = prio + 1;
+ if (cfqd->cur_prio > cfqd->cur_end_prio) {
+ cfqd->cur_end_prio = cfqd->cur_prio;
+ cfqd->cur_prio = 0;
+ }
+ if (cfqd->cur_end_prio == CFQ_PRIO_LISTS) {
+ cfqd->cur_prio = 0;
+ cfqd->cur_end_prio = 0;
}
- cfqd->active_queue = cfqq;
+ return prio;
}
static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
{
- struct cfq_queue *cfqq = cfq_get_next_cfqq(cfqd);
+ struct cfq_queue *cfqq = NULL;
+
+ /*
+ * if current list is non-empty, grab first entry. if it is empty,
+ * get next prio level and grab first entry then if any are spliced
+ */
+ if (!list_empty(&cfqd->cur_rr) || cfq_get_next_prio_level(cfqd) != -1)
+ cfqq = list_entry_cfqq(cfqd->cur_rr.next);
/*
* if we have idle queues and no rt or be queues had pending
@@ -976,6 +968,37 @@ static inline struct cfq_rq *cfq_check_f
}
/*
+ * Scale schedule slice based on io priority. Use the sync time slice only
+ * if a queue is marked sync and has sync io queued. A sync queue with async
+ * io only, should not get full sync slice length.
+ */
+static inline int
+cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ const int base_slice = cfqd->cfq_slice[cfq_cfqq_sync(cfqq)];
+
+ WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR);
+
+ return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - cfqq->ioprio));
+}
+
+static inline void
+cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ cfqq->slice_end = cfq_prio_to_slice(cfqd, cfqq) + jiffies;
+}
+
+static inline int
+cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ const int base_rq = cfqd->cfq_slice_async_rq;
+
+ WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR);
+
+ return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio));
+}
+
+/*
* get next queue for service
*/
static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
@@ -1092,6 +1115,7 @@ cfq_forced_dispatch(struct cfq_data *cfq
for (i = 0; i < CFQ_PRIO_LISTS; i++)
dispatched += cfq_forced_dispatch_cfqqs(&cfqd->rr_list[i]);
+ dispatched += cfq_forced_dispatch_cfqqs(&cfqd->busy_rr);
dispatched += cfq_forced_dispatch_cfqqs(&cfqd->cur_rr);
dispatched += cfq_forced_dispatch_cfqqs(&cfqd->idle_rr);
@@ -1331,11 +1355,6 @@ static void cfq_init_prio_data(struct cf
cfqq->org_ioprio = cfqq->ioprio;
cfqq->org_ioprio_class = cfqq->ioprio_class;
- /*
- * start priority
- */
- cfqq->dyn_ioprio = cfqq->ioprio;
-
if (cfq_cfqq_on_rr(cfqq))
cfq_resort_rr_list(cfqq, 0);
@@ -2210,6 +2229,7 @@ static int cfq_init_queue(request_queue_
for (i = 0; i < CFQ_PRIO_LISTS; i++)
INIT_LIST_HEAD(&cfqd->rr_list[i]);
+ INIT_LIST_HEAD(&cfqd->busy_rr);
INIT_LIST_HEAD(&cfqd->cur_rr);
INIT_LIST_HEAD(&cfqd->idle_rr);
INIT_LIST_HEAD(&cfqd->empty_list);
_
-
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