RE: LINT CPU features table
Let me turn my original inquiry into an offer: I volunteer to write the section for the Handbook or other documentation detailing the various CPU options in LINT if somebody who fully understands what these options do is willing to spend 30 minutes on the phone with me answering questions about the options. Any takers? Thanks, --Lucky To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: LINT CPU features table
If memory serves me right, Lucky Green wrote: Let me turn my original inquiry into an offer: I volunteer to write the section for the Handbook or other documentation detailing the various CPU options in LINT if somebody who fully understands what these options do is willing to spend 30 minutes on the phone with me answering questions about the options. Any takers? Hi Lucky-- An excellent idea. A few thoughts for you: 1. You could peruse recent release notes (at least for i386) to get started. What little I know about the CPU-related options is encapsulated there, so thirty minutes on the phone with me is not likely to be useful, BTW. :-p 2. The CPU options in LINT are both version- and architecture-dependent. This fact probably makes this information a good candidate for the architecture-dependent hardware notes in the release documentation, with a pointer from the Handbook. 3. If you want a review on markup (or you want someone to mark up text for you), freebsd-doc is a great place to send things for feedback. Good luck, and thanks for volunteering to document this stuff! Bruce. msg35196/pgp0.pgp Description: PGP signature
RE: LINT CPU features table
On Sat, 22 Jun 2002, Lucky Green wrote: Let me turn my original inquiry into an offer: I volunteer to write the section for the Handbook or other documentation detailing the various CPU options in LINT if somebody who fully understands what these options do is willing to spend 30 minutes on the phone with me answering questions about the options. Any takers? Thanks, --Lucky Despite your enthusiasm, it's still a rather pointless exercise. To make explaining the cpu options worthwhile, you must show that only specifying I686 is sufficiently more optimal than specifying I686/I586/I486/I386. Mike Silby Silbersack To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: LINT CPU features table
In the last episode (Jun 22), Mike Silbersack said: On Sat, 22 Jun 2002, Lucky Green wrote: Let me turn my original inquiry into an offer: I volunteer to write the section for the Handbook or other documentation detailing the various CPU options in LINT if somebody who fully understands what these options do is willing to spend 30 minutes on the phone with me answering questions about the options. Despite your enthusiasm, it's still a rather pointless exercise. To make explaining the cpu options worthwhile, you must show that only specifying I686 is sufficiently more optimal than specifying I686/I586/I486/I386. I think he's referring to the flotilla of CPU feature options, mainly aimed at AMD and old Cyrix processors. A while back I went through all the places the I?86_CPU defines were used and determined that the only option that degraded performace when added to a kernel that didn't need it was I386_CPU; due to the 386's lack of locking primitives. For 486 and higher chips it doesn't matter if you have all three I[456]86_CPU defined or just the one you need. Most of the code activated by the options are specialized bcopy routines accessed through an indirect pointer, or initialization code used only once during bootup. -- Dan Nelson [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: LINT CPU features table
On Sat, 22 Jun 2002, Dan Nelson wrote: In the last episode (Jun 22), Mike Silbersack said: On Sat, 22 Jun 2002, Lucky Green wrote: Let me turn my original inquiry into an offer: I volunteer to write the section for the Handbook or other documentation detailing the various CPU options in LINT if somebody who fully understands what these options do is willing to spend 30 minutes on the phone with me answering questions about the options. Despite your enthusiasm, it's still a rather pointless exercise. To make explaining the cpu options worthwhile, you must show that only specifying I686 is sufficiently more optimal than specifying I686/I586/I486/I386. I think he's referring to the flotilla of CPU feature options, mainly aimed at AMD and old Cyrix processors. [snip] I would argue that any effort put toward documenting this is better spent documenting something else. That particular flotilla of options relates entirely to a group of rather old, rather slow, and rather rare processors. The incidence of their use or necessity in the general FreeBSD user base is likely to be quite small. If you're running on asome ancient bastard child of Cyrix processor then chances are you're not running a performance critical application. At that level I say to anyone who tries to squeeze every last ounce of performance out of their CPU, buy a faster CPU or UTFSL. Feel free to disagree and work on what interests you. Brandon D. Valentine -- http://www.geekpunk.net [EMAIL PROTECTED] ++[++-][++-].[+-][+-]+.+++..++ +.+[++-]++.+++..+++.--..+. To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: LINT CPU features table
On 2002-06-16 22:38 -0500, Mike Silbersack wrote: On Sun, 16 Jun 2002, Lucky Green wrote: If only a few CPU's would benefit from the CPU-specific options, creating a table of CPU options for those few CPU's should be all the simpler. What I am I missing? IMHO, the performance benefits are so small, that it's best to not even concern people with making cpu-specific kernels. CPU-specific compiler options might actually make a difference, but those tend to create kernels that crash. Or do not work flawlessly across hardware upgrades. I have an installation here at home that has gone through many hardware upgrades (motherboard, cpu, or other vital parts) and has worked like a charm, compiling worlds since 3.2-RELEASE from source. Having a userland or kernel that is 486-specific would have been a major PITA when I changed the cpu to a Pentium, with a new PITA waiting at the next corner, when I switched to a Celeron, etc. I feel that it's very nice that uname -p and uname -m still print i386 in their output :-] - Giorgos To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: LINT CPU features table
On Fri, 7 Jun 2002, Lucky Green wrote: [This inquiry found no takers on -questions, so I am trying it on -hackers] I found the list of CPU options in LINT to be not very accessible. What would be considerably more useful, perhaps in addition to the information in LINT, would be a table of CPU's, with a checkbox for each CPU feature that should/could be enabled for this particular CPU. Is anybody here aware of such a table? If not, is anybody here able to perhaps create such a table and add it to the Handbook? I believe it would be of substantial help to the user. OK, I have an AMD K6-333. [User looks down the AMD K6 row of the table]. I can turn on feature L, M, and Y. Thanks in advance, --Lucky For most cpus, there is little to be gained by fiddling with cpu specific options. Hence, there is little reason to provide a complex table; having all cpu types enabled as in GENERIC is just fine. Mike Silby Silbersack To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
LINT CPU features table
[This inquiry found no takers on -questions, so I am trying it on -hackers] I found the list of CPU options in LINT to be not very accessible. What would be considerably more useful, perhaps in addition to the information in LINT, would be a table of CPU's, with a checkbox for each CPU feature that should/could be enabled for this particular CPU. Is anybody here aware of such a table? If not, is anybody here able to perhaps create such a table and add it to the Handbook? I believe it would be of substantial help to the user. OK, I have an AMD K6-333. [User looks down the AMD K6 row of the table]. I can turn on feature L, M, and Y. Thanks in advance, --Lucky To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
