Re: [PATCH v2] netfilter: nf_conntrack: use safer way to lock all buckets
From: Jesper Dangaard Brouer <hidden>
Date: 2016-01-15 07:07:01
Also in:
lkml, netfilter-devel
On Thu, 14 Jan 2016 12:03:56 -0500 Sasha Levin [off-list ref] wrote:
When we need to lock all buckets in the connection hashtable we'd attempt to lock 1024 spinlocks, which is way more preemption levels than supported by the kernel. Furthermore, this behavior was hidden by checking if lockdep is enabled, and if it was - use only 8 buckets(!). Fix this by using a global lock and synchronize all buckets on it when we need to lock them all. This is pretty heavyweight, but is only done when we need to resize the hashtable, and that doesn't happen often enough (or at all). Signed-off-by: Sasha Levin <redacted>
[...]
quoted hunk ↗ jump to hunk
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 3cb3cb8..4ccf5ad 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c@@ -66,6 +66,21 @@ EXPORT_SYMBOL_GPL(nf_conntrack_locks); __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock); EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock); +spinlock_t nf_conntrack_locks_all_lock; +bool nf_conntrack_locks_all;
You forgot to mark these static and __read_mostly as Florian pointed out... After that you can add my: Acked-by: Jesper Dangaard Brouer [off-list ref] -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer