diff options
| author | Benjamin LaHaise <bcrl@kvack.org> | 2008-01-30 12:33:13 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 12:33:13 (GMT) |
| commit | 0723a69a63beec1ca6e792239ef75d0181387ef0 (patch) | |
| tree | df0205d10a3811084923e8f24935e400e0a81667 | |
| parent | 6b8be6df7f971919622d152d144c8798ad7fd160 (diff) | |
| download | linux-fsl-qoriq-0723a69a63beec1ca6e792239ef75d0181387ef0.tar.xz | |
x86: fix synchronize_rcu(): high latency on idle system
an otherwise idle system takes about 3 ticks per network
interface in unregister_netdev() due to multiple calls to synchronize_rcu(),
which adds up to quite a few seconds for tearing down thousands of
interfaces. By flushing pending rcu callbacks in the idle loop, the system
makes progress hundreds of times faster. If this is indeed a sane thing to,
it probably needs to be done for other architectures than x86. And yes, the
network stack shouldn't call synchronize_rcu() quite so much, but fixing that
is a little more involved.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/kernel/process_32.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 7a61b54..69a69c3 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -198,6 +198,9 @@ void cpu_idle(void) rmb(); idle = pm_idle; + if (rcu_pending(cpu)) + rcu_check_callbacks(cpu, 0); + if (!idle) idle = default_idle; |