Date: Thu, 4 Jun 1998 10:41:01 -0700 (PDT) From: dima@best.net (Dima Ruban) To: peter@netplex.com.au (Peter Wemm) Cc: committers@FreeBSD.ORG Subject: Re: FD_SETSIZE Message-ID: <199806041741.KAA08545@burka.rdy.com> In-Reply-To: <199806041439.WAA24579@spinner.netplex.com.au> from Peter Wemm at "Jun 4, 98 10:39:21 pm"
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Peter Wemm writes: > Dima Ruban wrote: > > Hey guys! > > > > -current has Subject defined to 1024, -stable - to 256. > > Any objections from bumping it in -stable, so it would match > > value that we have in -current? > > If I recall correctly, the -current select() implementation was enhanced to > make better use of memory and copyin/out with large vector sizes. This has > not happened with -stable, so increasing the vector size might not be an > idea as it could have a [slight?] detrimental effect. I don't remember > the details of the situation well enough but I am pretty sure that there > was some reason why it wasn't taken across. I just went through a commit logs, and here we go: -- revision 1.19 date: 1996/08/20 07:17:48; author: smpatel; state: Exp; lines: +43 -15 Remove the kernel FD_SETSIZE limit for select(). Make select()'s first argument 'int' not 'u_int'. Reviewed by: bde -- revision 1.22 date: 1997/02/20 11:51:52; author: bde; state: Exp; lines: +51 -36 Improved select(): - avoid malloc() if the number of fds is small. - pack the bits better so that `small' is quite large. - don't waste time generating zero bits for null fd_set pointers or scanning these bits. Possibly improved select(): - free malloc()ed storage before returning. This is simpler and I think huge select()s aren't worth optimizing since they are rare, relative gain would be small and there would be tiny costs for all selects(). Reviewed by: ache (first version by him too) -- (that's for sys_generic.c) It looks like it would be relatively easy to bring this into -stable. > > Cheers, > -Peter > -- > Peter Wemm <peter@netplex.com.au> Netplex Consulting > > -- dima To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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