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authorMiroslav Urbanek <mu@miroslavurbanek.com>2016-11-21 17:48:21 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-12-10 21:09:44 +0300
commitbe5339492b2919a910bf06630a861d5da8a478bd (patch)
tree9a016960bc5acdc055768f5395db451ae2391f07
parent3a116fa8c95d4c16f864475c4fdd395fd2a6cce4 (diff)
downloadlinux-be5339492b2919a910bf06630a861d5da8a478bd.tar.xz
flowcache: Increase threshold for refusing new allocations
commit 6b226487815574193c1da864f2eac274781a2b0c upstream. The threshold for OOM protection is too small for systems with large number of CPUs. Applications report ENOBUFs on connect() every 10 minutes. The problem is that the variable net->xfrm.flow_cache_gc_count is a global counter while the variable fc->high_watermark is a per-CPU constant. Take the number of CPUs into account as well. Fixes: 6ad3122a08e3 ("flowcache: Avoid OOM condition under preasure") Reported-by: Lukáš Koldrt <lk@excello.cz> Tested-by: Jan Hejl <jh@excello.cz> Signed-off-by: Miroslav Urbanek <mu@miroslavurbanek.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/core/flow.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/net/core/flow.c b/net/core/flow.c
index 3937b1b68d5b..18e8893d4be5 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -95,7 +95,6 @@ static void flow_cache_gc_task(struct work_struct *work)
list_for_each_entry_safe(fce, n, &gc_list, u.gc_list) {
flow_entry_kill(fce, xfrm);
atomic_dec(&xfrm->flow_cache_gc_count);
- WARN_ON(atomic_read(&xfrm->flow_cache_gc_count) < 0);
}
}
@@ -236,9 +235,8 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
if (fcp->hash_count > fc->high_watermark)
flow_cache_shrink(fc, fcp);
- if (fcp->hash_count > 2 * fc->high_watermark ||
- atomic_read(&net->xfrm.flow_cache_gc_count) > fc->high_watermark) {
- atomic_inc(&net->xfrm.flow_cache_genid);
+ if (atomic_read(&net->xfrm.flow_cache_gc_count) >
+ 2 * num_online_cpus() * fc->high_watermark) {
flo = ERR_PTR(-ENOBUFS);
goto ret_object;
}