Gentoo Archives: gentoo-amd64

From: Mark Knecht <markknecht@×××××.com>
To: gentoo-amd64@l.g.o
Subject: Re: [gentoo-amd64] Please suggest settings and flags in /etc/make.conf?
Date: Fri, 22 Jan 2010 13:27:59
In Reply to: Re: [gentoo-amd64] Please suggest settings and flags in /etc/make.conf? by Lie Ryan
1 On Thu, Jan 21, 2010 at 11:52 PM, Lie Ryan <lie.1296@×××××.com> wrote:
2 > On 01/22/10 16:26, Peter Humphrey wrote:
3 >> On Friday 22 January 2010 03:05:55 Lie Ryan wrote:
4 >>> On 01/22/10 11:44, Mark Knecht wrote:
5 >>
6 >>>> # These are the USE flags that were used in addition to what is
7 >>>> provided by the # profile used for building.
8 >>>> USE="mmx sse sse2"
9 >>>
10 >>> No one size fits all, only you can decide the best USE flags combination
11 >>> for your use. You probably wouldn't know the USE flags to use until you
12 >>> emerged some programs. Before emerging, look at the USE flags and decide
13 >>> whether you will need the feature activated by the flag, and whether you
14 >>> want to activate the USE flags globally (add here) or locally for the
15 >>> specific package (in /etc/portage/package.use).
16 >>
17 >>>> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
18 >>>> mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
19 >>>> syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good
20 >>>> xtopology nonstop_tsc pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2
21 >>>> ssse3 cx16 xtpr pdcm sse4_1 sse4_2 aes lahf_lm ida tpr_shadow vnmi
22 >>>> flexpriority ept vpid
23 >>
24 >> What I did recently is to go through the list of CPU flags one by one and
25 >> check which of them had corresponding USE flags; I set those in make.conf on
26 >> the assumption that, if the processor had that feature, I might as well let
27 >> it use it.
28 >>
29 >
30 > I can tell you that's actually a lot of work. A certain technology may
31 > be called differently in the CPU flags and in USE flags; and often even
32 > after activating the USE flags, you may still need to find the feature
33 > in kernel config. I always wished there is a website that listed the CPU
34 > flags with the relevant kernel config and/or USE flags.
35 >
36 >
37 Agreed. Not that I'm signing up for doing a lot of work but what's
38 involved in starting some sort of small working group to maybe put
39 some of that info together informally? Maybe we can come up with
40 something over the next few months working together that could be the
41 basis of such a page?
43 - Mark