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authorSteffen Klassert <steffen.klassert@secunet.com>2015-09-29 12:40:49 +0300
committerSteffen Klassert <steffen.klassert@secunet.com>2015-09-29 12:44:16 +0300
commitc386578f1cdb4dac230395a951f88027f64346e3 (patch)
tree8e8442a599588ae8876e2d0dc0975602ab0dbd69 /Documentation/networking
parent8a4683a5e06efda7e1f327213678d4dcafc0d894 (diff)
downloadlinux-c386578f1cdb4dac230395a951f88027f64346e3.tar.xz
xfrm: Let the flowcache handle its size by default.
The xfrm flowcache size is limited by the flowcache limit (4096 * number of online cpus) and the xfrm garbage collector threshold (2 * 32768), whatever is reached first. This means that we can hit the garbage collector limit only on systems with more than 16 cpus. On such systems we simply refuse new allocations if we reach the limit, so new flows are dropped. On syslems with 16 or less cpus, we hit the flowcache limit. In this case, we shrink the flow cache instead of refusing new flows. We increase the xfrm garbage collector threshold to INT_MAX to get the same behaviour, independent of the number of cpus. The xfrm garbage collector threshold can still be set below the flowcache limit to reduce the memory usage of the flowcache. Tested-by: Dan Streetman <dan.streetman@canonical.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/ip-sysctl.txt6
1 files changed, 4 insertions, 2 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index ebe94f2cab98..260f30b2def6 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1199,7 +1199,8 @@ tag - INTEGER
xfrm4_gc_thresh - INTEGER
The threshold at which we will start garbage collecting for IPv4
destination cache entries. At twice this value the system will
- refuse new allocations.
+ refuse new allocations. The value must be set below the flowcache
+ limit (4096 * number of online cpus) to take effect.
igmp_link_local_mcast_reports - BOOLEAN
Enable IGMP reports for link local multicast groups in the
@@ -1645,7 +1646,8 @@ ratelimit - INTEGER
xfrm6_gc_thresh - INTEGER
The threshold at which we will start garbage collecting for IPv6
destination cache entries. At twice this value the system will
- refuse new allocations.
+ refuse new allocations. The value must be set below the flowcache
+ limit (4096 * number of online cpus) to take effect.
IPv6 Update by: