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authorJustin TerAvest <teravest@google.com>2011-03-01 15:05:08 -0500
committerJens Axboe <jaxboe@fusionio.com>2011-03-01 15:05:08 -0500
commit0bbfeb8320421989d3e12bd95fae86b9ac0712aa (patch)
treea23bb6686bd2586fe7c27d0773c63f9aeb254cd1 /block
parent6fae9c25134baffbeeb20031479e7ff6f6d8eec0 (diff)
downloadop-kernel-dev-0bbfeb8320421989d3e12bd95fae86b9ac0712aa.zip
op-kernel-dev-0bbfeb8320421989d3e12bd95fae86b9ac0712aa.tar.gz
cfq-iosched: Always provide group isolation.
Effectively, make group_isolation=1 the default and remove the tunable. The setting group_isolation=0 was because by default we idle on sync-noidle tree and on fast devices, this can be very harmful for throughput. However, this problem can also be addressed by tuning slice_idle and possibly group_idle on faster storage devices. This change simplifies the CFQ code by removing the feature entirely. Signed-off-by: Justin TerAvest <teravest@google.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block')
-rw-r--r--block/cfq-iosched.c37
1 files changed, 1 insertions, 36 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f27ff3e..3202c7e 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -146,7 +146,6 @@ struct cfq_queue {
struct cfq_rb_root *service_tree;
struct cfq_queue *new_cfqq;
struct cfq_group *cfqg;
- struct cfq_group *orig_cfqg;
/* Number of sectors dispatched from queue in single dispatch round */
unsigned long nr_sectors;
};
@@ -285,7 +284,6 @@ struct cfq_data {
unsigned int cfq_slice_idle;
unsigned int cfq_group_idle;
unsigned int cfq_latency;
- unsigned int cfq_group_isolation;
unsigned int cic_index;
struct list_head cic_list;
@@ -1187,32 +1185,6 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
int new_cfqq = 1;
int group_changed = 0;
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
- if (!cfqd->cfq_group_isolation
- && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD
- && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) {
- /* Move this cfq to root group */
- cfq_log_cfqq(cfqd, cfqq, "moving to root group");
- if (!RB_EMPTY_NODE(&cfqq->rb_node))
- cfq_group_service_tree_del(cfqd, cfqq->cfqg);
- cfqq->orig_cfqg = cfqq->cfqg;
- cfqq->cfqg = &cfqd->root_group;
- cfqd->root_group.ref++;
- group_changed = 1;
- } else if (!cfqd->cfq_group_isolation
- && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) {
- /* cfqq is sequential now needs to go to its original group */
- BUG_ON(cfqq->cfqg != &cfqd->root_group);
- if (!RB_EMPTY_NODE(&cfqq->rb_node))
- cfq_group_service_tree_del(cfqd, cfqq->cfqg);
- cfq_put_cfqg(cfqq->cfqg);
- cfqq->cfqg = cfqq->orig_cfqg;
- cfqq->orig_cfqg = NULL;
- group_changed = 1;
- cfq_log_cfqq(cfqd, cfqq, "moved to origin group");
- }
-#endif
-
service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq),
cfqq_type(cfqq));
if (cfq_class_idle(cfqq)) {
@@ -2542,7 +2514,7 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
static void cfq_put_queue(struct cfq_queue *cfqq)
{
struct cfq_data *cfqd = cfqq->cfqd;
- struct cfq_group *cfqg, *orig_cfqg;
+ struct cfq_group *cfqg;
BUG_ON(cfqq->ref <= 0);
@@ -2554,7 +2526,6 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
BUG_ON(rb_first(&cfqq->sort_list));
BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]);
cfqg = cfqq->cfqg;
- orig_cfqg = cfqq->orig_cfqg;
if (unlikely(cfqd->active_queue == cfqq)) {
__cfq_slice_expired(cfqd, cfqq, 0);
@@ -2564,8 +2535,6 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
BUG_ON(cfq_cfqq_on_rr(cfqq));
kmem_cache_free(cfq_pool, cfqq);
cfq_put_cfqg(cfqg);
- if (orig_cfqg)
- cfq_put_cfqg(orig_cfqg);
}
/*
@@ -3953,7 +3922,6 @@ static void *cfq_init_queue(struct request_queue *q)
cfqd->cfq_slice_idle = cfq_slice_idle;
cfqd->cfq_group_idle = cfq_group_idle;
cfqd->cfq_latency = 1;
- cfqd->cfq_group_isolation = 0;
cfqd->hw_tag = -1;
/*
* we optimistically start assuming sync ops weren't delayed in last
@@ -4029,7 +3997,6 @@ SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0);
-SHOW_FUNCTION(cfq_group_isolation_show, cfqd->cfq_group_isolation, 0);
#undef SHOW_FUNCTION
#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
@@ -4063,7 +4030,6 @@ STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
UINT_MAX, 0);
STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0);
-STORE_FUNCTION(cfq_group_isolation_store, &cfqd->cfq_group_isolation, 0, 1, 0);
#undef STORE_FUNCTION
#define CFQ_ATTR(name) \
@@ -4081,7 +4047,6 @@ static struct elv_fs_entry cfq_attrs[] = {
CFQ_ATTR(slice_idle),
CFQ_ATTR(group_idle),
CFQ_ATTR(low_latency),
- CFQ_ATTR(group_isolation),
__ATTR_NULL
};
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