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author | Florian Westphal <fw@strlen.de> | 2018-06-25 17:26:02 +0200 |
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committer | Steffen Klassert <steffen.klassert@secunet.com> | 2018-06-25 17:46:06 +0200 |
commit | e4db5b61c572475bbbcf63e3c8a2606bfccf2c9d (patch) | |
tree | 1c059749a92e5b8c47efc54d342184c2fc73aed9 /net/xfrm/xfrm_state.c | |
parent | f203b76d78092faf248db3f851840fbecf80b40e (diff) | |
download | linux-stable-e4db5b61c572475bbbcf63e3c8a2606bfccf2c9d.tar.gz linux-stable-e4db5b61c572475bbbcf63e3c8a2606bfccf2c9d.tar.bz2 linux-stable-e4db5b61c572475bbbcf63e3c8a2606bfccf2c9d.zip |
xfrm: policy: remove pcpu policy cache
Kristian Evensen says:
In a project I am involved in, we are running ipsec (Strongswan) on
different mt7621-based routers. Each router is configured as an
initiator and has around ~30 tunnels to different responders (running
on misc. devices). Before the flow cache was removed (kernel 4.9), we
got a combined throughput of around 70Mbit/s for all tunnels on one
router. However, we recently switched to kernel 4.14 (4.14.48), and
the total throughput is somewhere around 57Mbit/s (best-case). I.e., a
drop of around 20%. Reverting the flow cache removal restores, as
expected, performance levels to that of kernel 4.9.
When pcpu xdst exists, it has to be validated first before it can be
used.
A negative hit thus increases cost vs. no-cache.
As number of tunnels increases, hit rate decreases so this pcpu caching
isn't a viable strategy.
Furthermore, the xdst cache also needs to run with BH off, so when
removing this the bh disable/enable pairs can be removed too.
Kristian tested a 4.14.y backport of this change and reported
increased performance:
In our tests, the throughput reduction has been reduced from around -20%
to -5%. We also see that the overall throughput is independent of the
number of tunnels, while before the throughput was reduced as the number
of tunnels increased.
Reported-by: Kristian Evensen <kristian.evensen@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm/xfrm_state.c')
-rw-r--r-- | net/xfrm/xfrm_state.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 3803b6813fc5..e04a510ec992 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -735,10 +735,9 @@ restart: } out: spin_unlock_bh(&net->xfrm.xfrm_state_lock); - if (cnt) { + if (cnt) err = 0; - xfrm_policy_cache_flush(); - } + return err; } EXPORT_SYMBOL(xfrm_state_flush); |