path: root/Documentation/networking
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authorNikolay Aleksandrov <nikolay@redhat.com>2014-07-24 16:50:37 +0200
committerDavid S. Miller <davem@davemloft.net>2014-07-27 22:34:36 -0700
commit1bab4c75075b84675b96992ac47580a57c26958d (patch)
treed015ddcf9d9d16e423efb63e9ddbd46fb02d95c3 /Documentation/networking
parentab1c724f633080ed2e8a0cfe61654599b55cf8f9 (diff)
inet: frag: set limits and make init_net's high_thresh limit global
This patch makes init_net's high_thresh limit to be the maximum for all namespaces, thus introducing a global memory limit threshold equal to the sum of the individual high_thresh limits which are capped. It also introduces some sane minimums for low_thresh as it shouldn't be able to drop below 0 (or > high_thresh in the unsigned case), and overall low_thresh should not ever be above high_thresh, so we make the following relations for a namespace: init_net: high_thresh - max(not capped), min(init_net low_thresh) low_thresh - max(init_net high_thresh), min (0) all other namespaces: high_thresh = max(init_net high_thresh), min(namespace's low_thresh) low_thresh = max(namespace's high_thresh), min(0) The major issue with having low_thresh > high_thresh is that we'll schedule eviction but never evict anything and thus rely only on the timers. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
1 files changed, 2 insertions, 1 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index e8c304e37831..29a93518bf18 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -101,7 +101,8 @@ ipfrag_high_thresh - INTEGER
Maximum memory used to reassemble IP fragments. When
ipfrag_high_thresh bytes of memory is allocated for this purpose,
the fragment handler will toss packets until ipfrag_low_thresh
- is reached.
+ is reached. This also serves as a maximum limit to namespaces
+ different from the initial one.
ipfrag_low_thresh - INTEGER
Maximum memory used to reassemble IP fragments before the kernel

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