Author: W B Hacker Date: To: exim-users Subject: Re: [exim] number of named lists default
Philip Hazel wrote: > On Sun, 7 Jan 2007, Jethro R Binks wrote:
>
>> I've always thought that the default of 16 named lists to be rather low;
>> in testing a new configuration, I've found I'm now using more than that.
>
> I'm always very bad at guessing how many of anything people will
> actually use in practice.
>
>> Could I suggest an increase to the default in the source, to 32? Or is
>> more than 16 named lists unusual? Is there a notable cost in increasing
>> it?
>
> I think it is unusual, because nobody else has raised this before. There
> is a notable cost because the caching arrangements use bitmaps, 2 bits
> per list. There are two caches for each address (local part + domain).
> Thus, increasing to 32 would add 8 bytes in the data block that is used
> for each and every address. A message with 1000 addresses would use up
> another 8K of memory.
>
> I'm always cautious about increasing the size of that data block.
> Probably overly so, but I come from the days when memory was expensive.
>
>> I know I can change it myself at compile time, but I use the FreeBSD port,
>> and there is currently no facility provided to make that change.
Puzzled by that 'no facility' statement.
If vi is too much of a PITA, try one of the (many!) other editors.
>> I am
>> chatting to the port maintainer about it anyway, but I think a change to
>> the source default would be generally beneficial.
> > I think it would be worth discussing this on one of the mailing lists to
> see whether there is any general feeling that 16 is too small.
Two are pretty much essential. Dunno if I have ever needed four, let alone 16.
> I would
> be happier to see it left as it is by default - clearly having a way to
> adjust it for FreeBSD would be useful.
>
>
> Philip
>
It is 'adjusted' in *BSD the same way as for any other OS:
edit ~/Local/Makefile
Set MAX_NAMED_LIST = [some integer multiple of 16]
