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| author | Holger Eitzenberger <heitzenberger@astaro.com> | 2006-02-04 13:13:14 +0300 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-02-05 10:51:18 +0300 |
| commit | c2db292438c20c3f13db6e5563e0ce5b449bedac (patch) | |
| tree | 775c7aa2e2e6069cb238833e5328a7b42b23041a /net/ipv4 | |
| parent | ddc8d029ac6813827849801bce2d8c8813070db6 (diff) | |
| download | linux-c2db292438c20c3f13db6e5563e0ce5b449bedac.tar.xz | |
[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.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c index 641dbc477650..2fe64133bba3 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"); |