ipv4:correct description for tcp_max_syn_backlog

Since commit c5ed63d66f24(tcp: fix three tcp sysctls tuning),
sysctl_max_syn_backlog is determined by tcp_hashinfo->ehash_mask,
and the minimal value is 128, and it will increase in proportion to the
memory of machine.
The original description for tcp_max_syn_backlog and sysctl_max_syn_backlog
are out of date.

Changelog:
V2: update description for sysctl_max_syn_backlog

Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Reviewed-by: Shan Wei <shanwei88@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Peter Pan(潘卫平) 2011-12-05 21:39:41 +00:00 committed by David S. Miller
parent 65e9d805e9
commit 99b53bdd81
2 changed files with 9 additions and 8 deletions

View file

@ -282,11 +282,11 @@ tcp_max_ssthresh - INTEGER
Default: 0 (off)
tcp_max_syn_backlog - INTEGER
Maximal number of remembered connection requests, which are
still did not receive an acknowledgment from connecting client.
Default value is 1024 for systems with more than 128Mb of memory,
and 128 for low memory machines. If server suffers of overload,
try to increase this number.
Maximal number of remembered connection requests, which have not
received an acknowledgment from connecting client.
The minimal value is 128 for low memory machines, and it will
increase in proportion to the memory of machine.
If server suffers from overload, try increasing this number.
tcp_max_tw_buckets - INTEGER
Maximal number of timewait sockets held by system simultaneously.

View file

@ -26,10 +26,11 @@
* but then some measure against one socket starving all other sockets
* would be needed.
*
* It was 128 by default. Experiments with real servers show, that
* The minimum value of it is 128. Experiments with real servers show that
* it is absolutely not enough even at 100conn/sec. 256 cures most
* of problems. This value is adjusted to 128 for very small machines
* (<=32Mb of memory) and to 1024 on normal or better ones (>=256Mb).
* of problems.
* This value is adjusted to 128 for low memory machines,
* and it will increase in proportion to the memory of machine.
* Note : Dont forget somaxconn that may limit backlog too.
*/
int sysctl_max_syn_backlog = 256;