Building 64 bit binaries from source.

Zepiroth · 03-04-2008, 06:37 AM

dear Linux experts,

Currently I have a new AMD AthlonX2-64 box to be deployed as a core server for Nagios, Postfix, Apache-PHP-MySQL-Cacti and Squid. Since the microprocessor is 64 bit, I installed Centos 5 x86-64.
I intend to compile the applications from source and to utilize the full 64bit capability.

I already tried to add on the ./configure for Squid :
# env CFLAGS="-m64" ./configure

but it failed with segmentation fault.

my questions are :
1. Is there any guide to make sure that the build is using 64 bit ? or is it simply use the same ./configure and the compilation automatically producing 64 bit binaries ?

2. the installed RAM is only 1GB. As I read a reference on the web (http://www.cyberciti.biz/tips/maximu...ux-server.html), 64 bit processor will be an advantage when we have more than 64 GB of RAM. Is it worth to build 64 bit with this amount of RAM ? or is there any speed advantages for 64 bit binaries ?

any url references would be appreciated.
thank you in advance.

weisso5 · 03-04-2008, 11:14 AM

In regards to squid, i would recommend building the application as 32-bit, my reasons come from various posts on the squid-cache mailing lists, here are some snippets:

Quote:

I would probably recommend compiling Squid as a 32 bit application....However, Squid is designed and tested on 32 bits, and probably does not like 64 bits very well (well.. that said I did run Squid fine on Alpha some years back with only some small amount of patching required..) so in the end you probably get new more problems than the problems fixed by using 64bits, in addition to the substantial increase in memory usage.

Quote:

Secondly, are there any advantages to running Squid in 64bit mode?

Probably none, and quite likely more problems as very few people have
used Squid in 64bit mode..

There is some small benefits in compiling Squid with support for 64
bit file I/O, but this should be considered highly experimental at
this time and not recommended for production use..

One notable benefit of compiling Suqid 64 bits would be if you need to
make a really big Squid. A Squid compiled for 64 bits should have no
problem with upper limit on memory usage if you can afford the
memory.

64bits is generally a waste except for applications needing more than
2GB of memory or certain specific applications who benefit from the
64 bit integer math improvements (most applications are quite happy
with 32 bit integer math).

-weisso

Zepiroth · 03-11-2008, 03:54 AM

dear weisso5,

thank you.

regards,

Hong Liang.