Hello there, Looking over the man page for 'tcp' I came across a reference to tuning the 'TCP_SYNQ_HSIZE' parameter when increasing 'tcp_max_syn_backlog' above 1024. However, this static sizing was removed back in Linux 2.6.20 in favour of dynamic scaling - as part of commit 72a3effaf633bcae9034b7e176bdbd78d64a71db. I have included a patch below with reference to this commit, and that the process detailed is not required on >= Linux 2.6.20. This is my first patch for a man page, as well as groff, so I apologize if anything is incorrect. If so, please let me know and I will resolve and resubmit. This patch was prepared against the current HEAD - at time of writing - from the Kernel.org man-page repository (f6d086878485f63e390d10f59b6beae7b96c4120), which looks to be version 3.82. --- man7/tcp.7 | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/man7/tcp.7 b/man7/tcp.7 index 5723bde..794c636 100644 --- a/man7/tcp.7 +++ b/man7/tcp.7 @@ -530,12 +530,16 @@ The default value of 256 is increased to 1024 when the memory present in the system is adequate or greater (>= 128Mb), and reduced to 128 for those systems with very low memory (<= 32Mb). -It is recommended that if this -needs to be increased above 1024, TCP_SYNQ_HSIZE in + +Prior to Linux 2.6.20, +.\" commit 72a3effaf633bcae9034b7e176bdbd78d64a71db +it was recommended that if this needed to be increased above 1024, +the size of the SYNACK hash table (TCP_SYNQ_HSIZE) in .I include/net/tcp.h be modified to keep TCP_SYNQ_HSIZE*16<=tcp_max_syn_backlog, and the kernel be -recompiled. +recompiled. In Linux 2.6.20, the fixed sized TCP_SYNQ_HSIZE was removed +in favour of dynamic sizing. .TP .IR tcp_max_tw_buckets " (integer; default: see below; since Linux 2.4)" .\" Since 2.3.41 -- 1.9.1 Thank you for your time. Regards, Peter Adkins -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
