On 03/12/2015 08:15 AM, Peter Adkins wrote: > 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. Thanks, Peter! Applied. Cheers, Michael > --- > 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 > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- 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
