Messages in this thread Patch in this message | | | Date | Wed, 9 Dec 2009 09:55:20 GMT | From | tip-bot for Peter Zijlstra <> | Subject | [tip:sched/urgent] sched: Remove unnecessary RCU exclusion |
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Commit-ID: fb58bac5c75bfff8bbf7d02071a10a62f32fe28b Gitweb: http://git.kernel.org/tip/fb58bac5c75bfff8bbf7d02071a10a62f32fe28b Author: Peter Zijlstra <a.p.zijlstra@chello.nl> AuthorDate: Tue, 1 Dec 2009 12:21:47 +0100 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 9 Dec 2009 10:03:08 +0100
sched: Remove unnecessary RCU exclusion
As Nick pointed out, and realized by myself when doing: sched: Fix balance vs hotplug race the patch: sched: for_each_domain() vs RCU
is wrong, sched_domains are freed after synchronize_sched(), which means disabling preemption is enough.
Reported-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- kernel/sched_fair.c | 9 ++------- 1 files changed, 2 insertions(+), 7 deletions(-)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index e9f5dae..c163a28 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1403,7 +1403,6 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag new_cpu = prev_cpu; } - rcu_read_lock(); for_each_domain(cpu, tmp) { /* * If power savings logic is enabled for a domain, see if we @@ -1484,10 +1483,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag update_shares(tmp); } - if (affine_sd && wake_affine(affine_sd, p, sync)) { - new_cpu = cpu; - goto out; - } + if (affine_sd && wake_affine(affine_sd, p, sync)) + return cpu; while (sd) { int load_idx = sd->forkexec_idx; @@ -1528,8 +1525,6 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag /* while loop will break here if sd == NULL */ } -out: - rcu_read_unlock(); return new_cpu; } #endif /* CONFIG_SMP */
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