Skip to content

Commit

Permalink
cfq-iosched: More renaming to better represent wl_class and wl_type
Browse files Browse the repository at this point in the history 
Some more renaming. Again making the code uniform w.r.t use of
wl_class/class to represent IO class (RT, BE, IDLE) and using
wl_type/type to represent subclass (SYNC, SYNC-IDLE, ASYNC).

At places this patch shortens the string "workload" to "wl".
Renamed "saved_workload" to "saved_wl_type". Renamed
"saved_serving_class" to "saved_wl_class".

For uniformity with "saved_wl_*" variables, renamed "serving_class"
to "serving_wl_class" and renamed "serving_type" to "serving_wl_type".

Again, just trying to improve upon code uniformity and improve
readability. No functional change.

v2:
- Restored the usage of keyword "service" based on Jeff Moyer's feedback.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
  • Loading branch information
Vivek Goyal authored and Tejun Heo committed Jan 9, 2013
1 parent 3bf10fe commit 4d2ceea
Showing 1 changed file with 33 additions and 31 deletions.
64 changes: 33 additions & 31 deletions block/cfq-iosched.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -248,9 +248,9 @@ struct cfq_group {
struct cfq_rb_root service_trees[2][3];
struct cfq_rb_root service_tree_idle;

unsigned long saved_workload_slice;
enum wl_type_t saved_workload;
enum wl_class_t saved_serving_class;
unsigned long saved_wl_slice;
enum wl_type_t saved_wl_type;
enum wl_class_t saved_wl_class;

/* number of requests that are on the dispatch list or inside driver */
int dispatched;
Expand Down Expand Up @@ -280,8 +280,8 @@ struct cfq_data {
/*
* The priority currently being served
*/
enum wl_class_t serving_class;
enum wl_type_t serving_type;
enum wl_class_t serving_wl_class;
enum wl_type_t serving_wl_type;
unsigned long workload_expires;
struct cfq_group *serving_group;

Expand Down Expand Up @@ -1241,7 +1241,7 @@ cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg)

cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
cfq_group_service_tree_del(st, cfqg);
cfqg->saved_workload_slice = 0;
cfqg->saved_wl_slice = 0;
cfqg_stats_update_dequeue(cfqg);
}

Expand Down Expand Up @@ -1301,12 +1301,12 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,

/* This group is being expired. Save the context */
if (time_after(cfqd->workload_expires, jiffies)) {
cfqg->saved_workload_slice = cfqd->workload_expires
cfqg->saved_wl_slice = cfqd->workload_expires
- jiffies;
cfqg->saved_workload = cfqd->serving_type;
cfqg->saved_serving_class = cfqd->serving_class;
cfqg->saved_wl_type = cfqd->serving_wl_type;
cfqg->saved_wl_class = cfqd->serving_wl_class;
} else
cfqg->saved_workload_slice = 0;
cfqg->saved_wl_slice = 0;

cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
st->min_vdisktime);
Expand Down Expand Up @@ -2031,7 +2031,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
{
if (cfqq) {
cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d",
cfqd->serving_class, cfqd->serving_type);
cfqd->serving_wl_class, cfqd->serving_wl_type);
cfqg_stats_update_avg_queue_size(cfqq->cfqg);
cfqq->slice_start = 0;
cfqq->dispatch_start = jiffies;
Expand Down Expand Up @@ -2118,8 +2118,8 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
{
struct cfq_rb_root *service_tree =
service_tree_for(cfqd->serving_group, cfqd->serving_class,
cfqd->serving_type);
service_tree_for(cfqd->serving_group, cfqd->serving_wl_class,
cfqd->serving_wl_type);

if (!cfqd->rq_queued)
return NULL;
Expand Down Expand Up @@ -2523,28 +2523,29 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
unsigned count;
struct cfq_rb_root *st;
unsigned group_slice;
enum wl_class_t original_class = cfqd->serving_class;
enum wl_class_t original_class = cfqd->serving_wl_class;

/* Choose next priority. RT > BE > IDLE */
if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
cfqd->serving_class = RT_WORKLOAD;
cfqd->serving_wl_class = RT_WORKLOAD;
else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg))
cfqd->serving_class = BE_WORKLOAD;
cfqd->serving_wl_class = BE_WORKLOAD;
else {
cfqd->serving_class = IDLE_WORKLOAD;
cfqd->serving_wl_class = IDLE_WORKLOAD;
cfqd->workload_expires = jiffies + 1;
return;
}

if (original_class != cfqd->serving_class)
if (original_class != cfqd->serving_wl_class)
goto new_workload;

/*
* For RT and BE, we have to choose also the type
* (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload
* expiration time
*/
st = service_tree_for(cfqg, cfqd->serving_class, cfqd->serving_type);
st = service_tree_for(cfqg, cfqd->serving_wl_class,
cfqd->serving_wl_type);
count = st->count;

/*
Expand All @@ -2555,9 +2556,10 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)

new_workload:
/* otherwise select new workload type */
cfqd->serving_type =
cfq_choose_wl(cfqd, cfqg, cfqd->serving_class);
st = service_tree_for(cfqg, cfqd->serving_class, cfqd->serving_type);
cfqd->serving_wl_type = cfq_choose_wl(cfqd, cfqg,
cfqd->serving_wl_class);
st = service_tree_for(cfqg, cfqd->serving_wl_class,
cfqd->serving_wl_type);
count = st->count;

/*
Expand All @@ -2568,11 +2570,11 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
group_slice = cfq_group_slice(cfqd, cfqg);

slice = group_slice * count /
max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_class],
cfq_group_busy_queues_wl(cfqd->serving_class, cfqd,
max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class],
cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd,
cfqg));

if (cfqd->serving_type == ASYNC_WORKLOAD) {
if (cfqd->serving_wl_type == ASYNC_WORKLOAD) {
unsigned int tmp;

/*
Expand Down Expand Up @@ -2618,10 +2620,10 @@ static void cfq_choose_cfqg(struct cfq_data *cfqd)
cfqd->serving_group = cfqg;

/* Restore the workload type data */
if (cfqg->saved_workload_slice) {
cfqd->workload_expires = jiffies + cfqg->saved_workload_slice;
cfqd->serving_type = cfqg->saved_workload;
cfqd->serving_class = cfqg->saved_serving_class;
if (cfqg->saved_wl_slice) {
cfqd->workload_expires = jiffies + cfqg->saved_wl_slice;
cfqd->serving_wl_type = cfqg->saved_wl_type;
cfqd->serving_wl_class = cfqg->saved_wl_class;
} else
cfqd->workload_expires = jiffies - 1;

Expand Down Expand Up @@ -3404,7 +3406,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
return true;

/* Allow preemption only if we are idling on sync-noidle tree */
if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD &&
cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
new_cfqq->service_tree->count == 2 &&
RB_EMPTY_ROOT(&cfqq->sort_list))
Expand Down Expand Up @@ -3456,7 +3458,7 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
* doesn't happen
*/
if (old_type != cfqq_type(cfqq))
cfqq->cfqg->saved_workload_slice = 0;
cfqq->cfqg->saved_wl_slice = 0;

/*
* Put the new queue at the front of the of the current list,
Expand Down

0 comments on commit 4d2ceea

Please sign in to comment.