This is a note to let you know that I've just added the patch titled
flowcache: Increase threshold for refusing new allocations
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
flowcache-increase-threshold-for-refusing-new-allocations.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6b226487815574193c1da864f2eac274781a2b0c Mon Sep 17 00:00:00 2001
From: Miroslav Urbanek <mu@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 21 Nov 2016 15:48:21 +0100
Subject: flowcache: Increase threshold for refusing new allocations
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From: Miroslav Urbanek <mu@xxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxx>
Tested-by: Jan Hejl <jh@xxxxxxxxxx>
Signed-off-by: Miroslav Urbanek <mu@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/flow.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -95,7 +95,6 @@ static void flow_cache_gc_task(struct wo
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
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;
}
Patches currently in stable-queue which might be from mu@xxxxxxxxxxxxxxxxxxx are
queue-4.8/flowcache-increase-threshold-for-refusing-new-allocations.patch
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