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authorEric Dumazet <eric.dumazet@gmail.com>2011-06-08 17:35:34 +0400
committerDavid S. Miller <davem@davemloft.net>2011-06-09 04:05:30 +0400
commit4b9d9be839fdb7dcd7ce7619a623fd9015a50cda (patch)
treebd1827203efe27578b783c30b0ff5e2d4966b26a /Documentation/networking
parent9ad7c049f0f79c418e293b1b68cf10d68f54fcdb (diff)
downloadlinux-4b9d9be839fdb7dcd7ce7619a623fd9015a50cda.tar.xz
inetpeer: remove unused list
Andi Kleen and Tim Chen reported huge contention on inetpeer unused_peers.lock, on memcached workload on a 40 core machine, with disabled route cache. It appears we constantly flip peers refcnt between 0 and 1 values, and we must insert/remove peers from unused_peers.list, holding a contended spinlock. Remove this list completely and perform a garbage collection on-the-fly, at lookup time, using the expired nodes we met during the tree traversal. This removes a lot of code, makes locking more standard, and obsoletes two sysctls (inet_peer_gc_mintime and inet_peer_gc_maxtime). This also removes two pointers in inet_peer structure. There is still a false sharing effect because refcnt is in first cache line of object [were the links and keys used by lookups are located], we might move it at the end of inet_peer structure to let this first cache line mostly read by cpus. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Andi Kleen <andi@firstfloor.org> CC: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/ip-sysctl.txt10
1 files changed, 0 insertions, 10 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index d3d653a5f9b9..3dcb26cd33f6 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -106,16 +106,6 @@ inet_peer_maxttl - INTEGER
when the number of entries in the pool is very small).
Measured in seconds.
-inet_peer_gc_mintime - INTEGER
- Minimum interval between garbage collection passes. This interval is
- in effect under high memory pressure on the pool.
- Measured in seconds.
-
-inet_peer_gc_maxtime - INTEGER
- Minimum interval between garbage collection passes. This interval is
- in effect under low (or absent) memory pressure on the pool.
- Measured in seconds.
-
TCP variables:
somaxconn - INTEGER