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authorHolger Eitzenberger <heitzenberger@astaro.com>2006-02-04 02:13:14 -0800
committerDavid S. Miller <davem@sunset.davemloft.net>2006-02-04 23:51:18 -0800
commitc2db292438c20c3f13db6e5563e0ce5b449bedac (patch)
tree775c7aa2e2e6069cb238833e5328a7b42b23041a /net/ipv4
parentddc8d029ac6813827849801bce2d8c8813070db6 (diff)
downloadop-kernel-dev-c2db292438c20c3f13db6e5563e0ce5b449bedac.zip
op-kernel-dev-c2db292438c20c3f13db6e5563e0ce5b449bedac.tar.gz
[NETFILTER]: ULOG/nfnetlink_log: Use better default value for 'nlbufsiz'
Performance tests showed that ULOG may fail on heavy loaded systems because of failed order-N allocations (N >= 1). The default value of 4096 is not optimal in the sense that it actually allocates _two_ contigous physical pages. Reasoning: ULOG uses alloc_skb(), which adds another ~300 bytes for skb_shared_info. This patch sets the default value to NLMSG_GOODSIZE and adds some documentation at the top. Signed-off-by: Holger Eitzenberger <heitzenberger@astaro.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/netfilter/ipt_ULOG.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 641dbc4..2fe6413 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -35,6 +35,10 @@
* each nlgroup you are using, so the total kernel memory usage increases
* by that factor.
*
+ * Actually you should use nlbufsiz a bit smaller than PAGE_SIZE, since
+ * nlbufsiz is used with alloc_skb, which adds another
+ * sizeof(struct skb_shared_info). Use NLMSG_GOODSIZE instead.
+ *
* flushtimeout:
* Specify, after how many hundredths of a second the queue should be
* flushed even if it is not full yet.
@@ -76,7 +80,7 @@ MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NFLOG);
#define PRINTR(format, args...) do { if (net_ratelimit()) printk(format , ## args); } while (0)
-static unsigned int nlbufsiz = 4096;
+static unsigned int nlbufsiz = NLMSG_GOODSIZE;
module_param(nlbufsiz, uint, 0400);
MODULE_PARM_DESC(nlbufsiz, "netlink buffer size");
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