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authorMichal Kubeček <mkubecek@suse.cz>2013-08-01 12:04:14 +0400
committerDavid S. Miller <davem@davemloft.net>2013-08-02 01:16:20 +0400
commit2ac3ac8f86f2fe065d746d9a9abaca867adec577 (patch)
tree6d0513fcc4e048797a417174a667b7c562535ddb /include
parent1f1059fcf0b30deb1cf1e23af9ef4231c0bcc0bb (diff)
downloadlinux-2ac3ac8f86f2fe065d746d9a9abaca867adec577.tar.xz
ipv6: prevent fib6_run_gc() contention
On a high-traffic router with many processors and many IPv6 dst entries, soft lockup in fib6_run_gc() can occur when number of entries reaches gc_thresh. This happens because fib6_run_gc() uses fib6_gc_lock to allow only one thread to run the garbage collector but ip6_dst_gc() doesn't update net->ipv6.ip6_rt_last_gc until fib6_run_gc() returns. On a system with many entries, this can take some time so that in the meantime, other threads pass the tests in ip6_dst_gc() (ip6_rt_last_gc is still not updated) and wait for the lock. They then have to run the garbage collector one after another which blocks them for quite long. Resolve this by replacing special value ~0UL of expire parameter to fib6_run_gc() by explicit "force" parameter to choose between spin_lock_bh() and spin_trylock_bh() and call fib6_run_gc() with force=false if gc_thresh is reached but not max_size. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/net/ip6_fib.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 2a601e7da1bf..48ec25a7fcb6 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -300,7 +300,7 @@ extern void inet6_rt_notify(int event, struct rt6_info *rt,
struct nl_info *info);
extern void fib6_run_gc(unsigned long expires,
- struct net *net);
+ struct net *net, bool force);
extern void fib6_gc_cleanup(void);