diff options
| author | Christoph Lameter <clameter@sgi.com> | 2006-12-10 02:20:29 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-10 09:55:43 -0800 |
| commit | 08c183f31bdbb709f177f6d3110d5f288ea33933 (patch) | |
| tree | be7b84c07f3b0bf29473bad2b7b788fa189f948e /kernel/sched.c | |
| parent | 1bd77f2da58e9cdd1f159217887343dadd9af417 (diff) | |
| download | lwn-08c183f31bdbb709f177f6d3110d5f288ea33933.tar.gz lwn-08c183f31bdbb709f177f6d3110d5f288ea33933.zip | |
[PATCH] sched: add option to serialize load balancing
Large sched domains can be very expensive to scan. Add an option SD_SERIALIZE
to the sched domain flags. If that flag is set then we make sure that no
other such domain is being balanced.
[akpm@osdl.org: build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Peter Williams <pwil3058@bigpond.net.au>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 0a4a26b21f69..2b2b780939c9 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2880,6 +2880,7 @@ static void update_load(struct rq *this_rq) * * Balancing parameters are set up in arch_init_sched_domains. */ +static DEFINE_SPINLOCK(balancing); static void run_rebalance_domains(struct softirq_action *h) { @@ -2909,6 +2910,11 @@ static void run_rebalance_domains(struct softirq_action *h) if (unlikely(!interval)) interval = 1; + if (sd->flags & SD_SERIALIZE) { + if (!spin_trylock(&balancing)) + goto out; + } + if (time_after_eq(jiffies, sd->last_balance + interval)) { if (load_balance(this_cpu, this_rq, sd, idle)) { /* @@ -2920,6 +2926,9 @@ static void run_rebalance_domains(struct softirq_action *h) } sd->last_balance = jiffies; } + if (sd->flags & SD_SERIALIZE) + spin_unlock(&balancing); +out: if (time_after(next_balance, sd->last_balance + interval)) next_balance = sd->last_balance + interval; } |