[patch 2/5] sched: (cleanup) remove redundant cfs_rq checks

Paul Turner
2011-01-22T05:04:41Z

[-- Attachment #1: sched-remove_cfs_rq_checks.patch --]
[-- Type: text/plain, Size: 1252 bytes --]

Since updates are against an entity's queuing cfs_rq it's not possible to
enter update_cfs_{shares,load} with a NULL cfs_rq. (Indeed, update_cfs_load
would crash prior to the check if we did anyway since we load is examined
during the initializers). Also, in the update_cfs_load case there's no point
in maintaining averages for rq->cfs_rq since we don't perform shares
distribution at that level -- NULL check is replaced accordingly.

Thanks to Dan Carpenter for pointing out the deference before NULL check.

Signed-off-by: Paul Turner <pjt@google.com>

---
kernel/sched_fair.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

Index: tip3/kernel/sched_fair.c
===================================================================
--- tip3.orig/kernel/sched_fair.c
+++ tip3/kernel/sched_fair.c
@@ -721,7 +721,7 @@ static void update_cfs_load(struct cfs_r
u64 now, delta;
unsigned long load = cfs_rq->load.weight;

- if (!cfs_rq)
+ if (cfs_rq->tg == &root_task_group)
return;

now = rq_of(cfs_rq)->clock;
@@ -784,9 +784,6 @@ static void update_cfs_shares(struct cfs
struct sched_entity *se;
long load_weight, load, shares;

- if (!cfs_rq)
- return;
-
tg = cfs_rq->tg;
se = tg->se[cpu_of(rq_of(cfs_rq))];
if (!se)