Date: Sat, 27 Nov 1999 18:43:27 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: John Polstra <jdp@polstra.com> Cc: wollman@khavrinen.lcs.mit.edu, current@FreeBSD.ORG Subject: Re: Route table leaks Message-ID: <199911280243.SAA40107@apollo.backplane.com> References: <199911220150.UAA78559@khavrinen.lcs.mit.edu> <XFMail.991121195840.jdp@polstra.com> <199911221552.KAA84691@khavrinen.lcs.mit.edu> <199911270141.RAA29416@vashon.polstra.com>
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:+ s = splnet();
:+ RTFREE(rt);
:+ splx(s);
:...
:+ s = splnet();
:+ RTFREE(rt);
:+ splx(s);
:+ }
: ro->ro_rt = rtalloc1(&ro->ro_dst, 1, ignore);
: }
:
:
:Now for my questions:
:
:1. Do I really need the splnet calls around RTFREE?
Yes. Because the route table may be flushed from an interrupt in
a low memory situation.
:2. To eliminate all the duplicated code, shall I make rtalloc just
:call rtalloc_ign(ro, 0UL)? I assume that was avoided originally for
:performance reasons, but now there's more code than before.
:
:John
:--
: John Polstra jdp@polstra.com
Hmm. One trick I used in the VM code was to put the common code in an
inline static function and leave the external functions broken out to
avoid an unnecessary call chain.
So, for example, if rtalloc() and rtalloc_ign() require a bunch of extra
code prior to calling rtalloc1(), then a good solution would be to put
the bulk of that code or perhaps even all of it in an inline and then
have rtalloc() and rtalloc_ign() both call the inline with appropriate
arguments.
Remember that inline function calls *WILL* optimize constants passed
as arguments. It's a very effective way to genericize a block of code
without creating any procedural recursion.
-Matt
Matthew Dillon
<dillon@backplane.com>
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