[PATCH][1/1] Per-priority statistics for CFQ w/iopriorities 2.6.8.1

From: Shailabh Nagar
Date: Fri Sep 24 2004 - 18:49:55 EST

This patch applies over the port of I/O priorities to CFQ for 2.6.8.1
posted earlier.

It adds useful statistics like requests and sectors received/served
and number of dynamic queue addition/deletions for each priority level (0 through 20) created by the earlier patch.

The patch is not required for correct functioning of the I/O priority port.

-- Shailabh





diff -Nru a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
--- a/drivers/block/cfq-iosched.c Fri Sep 24 19:16:53 2004
+++ b/drivers/block/cfq-iosched.c Fri Sep 24 19:16:53 2004
@@ -91,6 +91,15 @@
int busy_queues;
int busy_rq;
unsigned long busy_sectors;
+
+ /* requests, sectors and queues
+ * added(in),dispatched/deleted(out)
+ * at this priority level.
+ */
+ atomic_t cum_rq_in,cum_rq_out;
+ atomic_t cum_sectors_in,cum_sectors_out;
+ atomic_t cum_queues_in,cum_queues_out;
+
struct list_head prio_list;
int last_rq;
int last_sectors;
@@ -240,7 +249,9 @@
cfqd->cid[crq->ioprio].busy_rq--;
cfqd->cid[crq->ioprio].busy_sectors -= crq->nr_sectors;
}
-
+ atomic_inc(&(cfqd->cid[crq->ioprio].cum_rq_out));
+ atomic_add(crq->nr_sectors,
+ &(cfqd->cid[crq->ioprio].cum_sectors_out));
cfqq->queued[rq_data_dir(crq->request)]--;
rb_erase(&crq->rb_node, &cfqq->sort_list);
}
@@ -283,6 +294,9 @@
cfqd->cid[crq->ioprio].busy_rq++;
cfqd->cid[crq->ioprio].busy_sectors += crq->nr_sectors;
}
+ atomic_inc(&(cfqd->cid[crq->ioprio].cum_rq_in));
+ atomic_add(crq->nr_sectors,
+ &(cfqd->cid[crq->ioprio].cum_sectors_in));
retry:
__alias = __cfq_add_crq_rb(cfqq, crq);
if (!__alias) {
@@ -399,6 +413,7 @@
{
struct cfq_data *cfqd = q->elevator.elevator_data;
struct cfq_rq *crq = RQ_ELV_DATA(req);
+ int tmp;

cfq_del_crq_hash(crq);
cfq_add_crq_hash(cfqd, crq);
@@ -410,9 +425,11 @@
cfq_add_crq_rb(cfqd, cfqq, crq);
}

- cfqd->busy_sectors += req->hard_nr_sectors - crq->nr_sectors;
- cfqd->cid[crq->ioprio].busy_sectors +=
- req->hard_nr_sectors - crq->nr_sectors;
+ tmp = req->hard_nr_sectors - crq->nr_sectors;
+ cfqd->busy_sectors += tmp;
+ cfqd->cid[crq->ioprio].busy_sectors += tmp;
+ atomic_add(tmp,&(cfqd->cid[crq->ioprio].cum_sectors_in));
+
crq->nr_sectors = req->hard_nr_sectors;

q->last_merge = req;
@@ -683,6 +700,7 @@

cfqd->cid[cfqq->ioprio].busy_queues--;
WARN_ON(cfqd->cid[cfqq->ioprio].busy_queues < 0);
+ atomic_inc(&(cfqd->cid[cfqq->ioprio].cum_queues_out));

list_del(&cfqq->cfq_list);
hlist_del(&cfqq->cfq_hash);
@@ -756,7 +774,9 @@
if (!list_empty(&cfqq->cfq_list)) {
cfqd->cid[cfqq->ioprio].busy_queues--;
WARN_ON(cfqd->cid[cfqq->ioprio].busy_queues<0);
+ atomic_inc(&(cfqd->cid[cfqq->ioprio].cum_queues_out));
cfqd->cid[prio].busy_queues++;
+ atomic_inc(&(cfqd->cid[prio].cum_queues_in));
list_move_tail(&cfqq->cfq_list,
&cfqd->cid[prio].rr_list);
}
@@ -769,6 +789,7 @@
list_add_tail(&cfqq->cfq_list,
&cfqd->cid[prio].rr_list);
cfqd->cid[prio].busy_queues++;
+ atomic_inc(&(cfqd->cid[prio].cum_queues_in));
cfqd->busy_queues++;
}

@@ -1052,6 +1073,13 @@
INIT_LIST_HEAD(&cid->prio_list);
cid->last_rq = -1;
cid->last_sectors = -1;
+
+ atomic_set(&cid->cum_rq_in,0);
+ atomic_set(&cid->cum_rq_out,0);
+ atomic_set(&cid->cum_sectors_in,0);
+ atomic_set(&cid->cum_sectors_out,0);
+ atomic_set(&cid->cum_queues_in,0);
+ atomic_set(&cid->cum_queues_out,0);
}

cfqd->crq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_MHASH_ENTRIES,
@@ -1179,6 +1207,100 @@
STORE_FUNCTION(cfq_grace_idle_store, &cfqd->cfq_grace_idle, 0, INT_MAX);
#undef STORE_FUNCTION

+
+/* Additional entries to get priority level data */
+static ssize_t
+cfq_prio_show(struct cfq_data *cfqd, char *page, unsigned int priolvl)
+{
+ int r1,r2,s1,s2,q1,q2;
+
+ if (!(priolvl >= IOPRIO_IDLE && priolvl <= IOPRIO_RT))
+ return 0;
+
+ r1 = (int)atomic_read(&(cfqd->cid[priolvl].cum_rq_in));
+ r2 = (int)atomic_read(&(cfqd->cid[priolvl].cum_rq_out));
+ s1 = (int)atomic_read(&(cfqd->cid[priolvl].cum_sectors_in));
+ s2 = (int)atomic_read(&(cfqd->cid[priolvl].cum_sectors_out));
+ q1 = (int)atomic_read(&(cfqd->cid[priolvl].cum_queues_in));
+ q2 = (int)atomic_read(&(cfqd->cid[priolvl].cum_queues_out));
+
+ return sprintf(page,"rq (%d,%d) sec (%d,%d) q (%d,%d)\n",
+ r1,r2,
+ s1,s2,
+ q1,q2);
+}
+
+#define SHOW_PRIO_DATA(__PRIOLVL) \
+static ssize_t cfq_prio_##__PRIOLVL##_show(struct cfq_data *cfqd, char *page) \
+{ \
+ return cfq_prio_show(cfqd,page,__PRIOLVL); \
+}
+SHOW_PRIO_DATA(0);
+SHOW_PRIO_DATA(1);
+SHOW_PRIO_DATA(2);
+SHOW_PRIO_DATA(3);
+SHOW_PRIO_DATA(4);
+SHOW_PRIO_DATA(5);
+SHOW_PRIO_DATA(6);
+SHOW_PRIO_DATA(7);
+SHOW_PRIO_DATA(8);
+SHOW_PRIO_DATA(9);
+SHOW_PRIO_DATA(10);
+SHOW_PRIO_DATA(11);
+SHOW_PRIO_DATA(12);
+SHOW_PRIO_DATA(13);
+SHOW_PRIO_DATA(14);
+SHOW_PRIO_DATA(15);
+SHOW_PRIO_DATA(16);
+SHOW_PRIO_DATA(17);
+SHOW_PRIO_DATA(18);
+SHOW_PRIO_DATA(19);
+SHOW_PRIO_DATA(20);
+#undef SHOW_PRIO_DATA
+
+
+static ssize_t cfq_prio_store(struct cfq_data *cfqd, const char *page, size_t count, int priolvl)
+{
+ atomic_set(&(cfqd->cid[priolvl].cum_rq_in),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_rq_out),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_sectors_in),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_sectors_out),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_queues_in),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_queues_out),0);
+
+ return count;
+}
+
+
+#define STORE_PRIO_DATA(__PRIOLVL) \
+static ssize_t cfq_prio_##__PRIOLVL##_store(struct cfq_data *cfqd, const char *page, size_t count) \
+{ \
+ return cfq_prio_store(cfqd,page,count,__PRIOLVL); \
+}
+STORE_PRIO_DATA(0);
+STORE_PRIO_DATA(1);
+STORE_PRIO_DATA(2);
+STORE_PRIO_DATA(3);
+STORE_PRIO_DATA(4);
+STORE_PRIO_DATA(5);
+STORE_PRIO_DATA(6);
+STORE_PRIO_DATA(7);
+STORE_PRIO_DATA(8);
+STORE_PRIO_DATA(9);
+STORE_PRIO_DATA(10);
+STORE_PRIO_DATA(11);
+STORE_PRIO_DATA(12);
+STORE_PRIO_DATA(13);
+STORE_PRIO_DATA(14);
+STORE_PRIO_DATA(15);
+STORE_PRIO_DATA(16);
+STORE_PRIO_DATA(17);
+STORE_PRIO_DATA(18);
+STORE_PRIO_DATA(19);
+STORE_PRIO_DATA(20);
+#undef STORE_PRIO_DATA
+
+
static struct cfq_fs_entry cfq_quantum_entry = {
.attr = {.name = "quantum", .mode = S_IRUGO | S_IWUSR },
.show = cfq_quantum_show,
@@ -1215,6 +1337,58 @@
.store = cfq_grace_idle_store,
};

+#define P_0_STR "p0"
+#define P_1_STR "p1"
+#define P_2_STR "p2"
+#define P_3_STR "p3"
+#define P_4_STR "p4"
+#define P_5_STR "p5"
+#define P_6_STR "p6"
+#define P_7_STR "p7"
+#define P_8_STR "p8"
+#define P_9_STR "p9"
+#define P_10_STR "p10"
+#define P_11_STR "p11"
+#define P_12_STR "p12"
+#define P_13_STR "p13"
+#define P_14_STR "p14"
+#define P_15_STR "p15"
+#define P_16_STR "p16"
+#define P_17_STR "p17"
+#define P_18_STR "p18"
+#define P_19_STR "p19"
+#define P_20_STR "p20"
+
+
+#define CFQ_PRIO_SYSFS_ENTRY(__PRIOLVL) \
+static struct cfq_fs_entry cfq_prio_##__PRIOLVL##_entry = { \
+ .attr = {.name = P_##__PRIOLVL##_STR, .mode = S_IRUGO | S_IWUSR }, \
+ .show = cfq_prio_##__PRIOLVL##_show, \
+ .store = cfq_prio_##__PRIOLVL##_store, \
+};
+CFQ_PRIO_SYSFS_ENTRY(0);
+CFQ_PRIO_SYSFS_ENTRY(1);
+CFQ_PRIO_SYSFS_ENTRY(2);
+CFQ_PRIO_SYSFS_ENTRY(3);
+CFQ_PRIO_SYSFS_ENTRY(4);
+CFQ_PRIO_SYSFS_ENTRY(5);
+CFQ_PRIO_SYSFS_ENTRY(6);
+CFQ_PRIO_SYSFS_ENTRY(7);
+CFQ_PRIO_SYSFS_ENTRY(8);
+CFQ_PRIO_SYSFS_ENTRY(9);
+CFQ_PRIO_SYSFS_ENTRY(10);
+CFQ_PRIO_SYSFS_ENTRY(11);
+CFQ_PRIO_SYSFS_ENTRY(12);
+CFQ_PRIO_SYSFS_ENTRY(13);
+CFQ_PRIO_SYSFS_ENTRY(14);
+CFQ_PRIO_SYSFS_ENTRY(15);
+CFQ_PRIO_SYSFS_ENTRY(16);
+CFQ_PRIO_SYSFS_ENTRY(17);
+CFQ_PRIO_SYSFS_ENTRY(18);
+CFQ_PRIO_SYSFS_ENTRY(19);
+CFQ_PRIO_SYSFS_ENTRY(20);
+#undef CFQ_PRIO_SYSFS_ENTRY
+
static struct attribute *default_attrs[] = {
&cfq_quantum_entry.attr,
&cfq_quantum_io_entry.attr,
@@ -1223,6 +1397,27 @@
&cfq_queued_entry.attr,
&cfq_grace_rt_entry.attr,
&cfq_grace_idle_entry.attr,
+ &cfq_prio_0_entry.attr,
+ &cfq_prio_1_entry.attr,
+ &cfq_prio_2_entry.attr,
+ &cfq_prio_3_entry.attr,
+ &cfq_prio_4_entry.attr,
+ &cfq_prio_5_entry.attr,
+ &cfq_prio_6_entry.attr,
+ &cfq_prio_7_entry.attr,
+ &cfq_prio_8_entry.attr,
+ &cfq_prio_9_entry.attr,
+ &cfq_prio_10_entry.attr,
+ &cfq_prio_11_entry.attr,
+ &cfq_prio_12_entry.attr,
+ &cfq_prio_13_entry.attr,
+ &cfq_prio_14_entry.attr,
+ &cfq_prio_15_entry.attr,
+ &cfq_prio_16_entry.attr,
+ &cfq_prio_17_entry.attr,
+ &cfq_prio_18_entry.attr,
+ &cfq_prio_19_entry.attr,
+ &cfq_prio_20_entry.attr,
NULL,
};