March 2005 - openSUSE AMD64 - openSUSE Mailing Lists

Hardware, RAM, databus
by Colin Carter 13 Mar '05

13 Mar '05

Greetings, What I really need to know is how modern 64 bit memory is addressed. I already understand that if I have a pointer, ptr, which points to an array of some structure then ptr++ will point to the next element. That is, Ptr++ increments in a multiple of bytes. But that is all done in software. I want to optimise my software to match what happens in hardware. If I have a pointer pointing to address 256 and then look at address 257, by how many BYTES have I jumped in physical memory? In old style memory of 16 bit words it would jump one word, that is 4 BYTES, but in a machine with 8 bit words it would jump one word of 2 BYTES. That is, always one machine word. Also, if your machine was up to date, it always had the matching data bus to access a full word (machine word, not a Bill Gates 'word') in one take. That is, a 16 bit machine had a 16 bit databus. Cheap machines, with a cheap data-bus, would take two mouths full. An equivalent question would be: If I have a string, Str(16), of bytes Str(0) to Str(15) containing "ABCDEFGHIJKLMNOn" (n=NUL) in a 32 bit machine, does the request for Str(9) ie "J" electronically load this character directly into the least significant byte of the register, (doubt it) or, by assembler code (generated by the compiler) do the following: Load the characters "IJKL" into the register, shift right, ("00IJ") and mask ("oooJ") ? That is: does the electronic system access one byte directly? or perhaps the load/shift/mask is done in hardware? (doubt it) For me the important issue is, for a 64 bit machine: I suspect that access to IntArray(23) is faster if defined as int64_t IntArray(128) ie as 64 bit words with the top bits generally being zero than if defined as int32_t IntArray(128) ie as 32 bit words because, for a 64 bit machine, the latter will store two values into each physical address. (I must experiment with int_fast32_t ) (In a 32 bit machine everybody knows that it requires two bites of the cherry to get a 64 bit integer or float value.) The significance of this last question would be that there may be no value in having data 'nn byte aligned'. Finally, I am aware that modern machines have a cache. When I ask for the value of K, as in M = N + K, does the machine load a whole page to get N and another page to get K? If these are int32_t does the memory do a 32 bit pulse/read of one address? Or perhaps a 64 bit pulse/read and mask? or repeated reads for a whole page? Does the AMD64 have a 32 bit databus or a 64 bit databus? Thanks to any hardware boffins, Colin

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XEN for AMD64
by Arjen Runsink 12 Mar '05

12 Mar '05

Hi, Does anyone know if the XEN, which will come with 9.3, will also work with the 64bit kernels? BB, Arjen

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Re: [suse-amd64] Suse 9.3 - which kernel and gcc ?
by Andreas Jaeger 12 Mar '05

12 Mar '05

"Joel Wiramu Pauling" <aenertia(a)aenertia.net> writes: > Are the gnome 2.10 rpm's available somewhere now? Not done yet, I'll talk to the guys later. > I've been hanging out for 2.10 rpm's for amd64 for a while... It would > be nice to make these available through an apt repository or YOU update > for all the 9.2 folks in strange parts of the World (i.e NZ) whom will > have to get a Quazi legal version of 9.3 dvd because it takes months to > get here, and by that time it's out of date. Andreas P.S.: I shipped the first 9.2 version myself last November to NZ. -- Andreas Jaeger, aj(a)suse.de, http://www.suse.de/~aj SUSE Linux Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GPG fingerprint = 93A3 365E CE47 B889 DF7F FED1 389A 563C C272 A126

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Re: [suse-amd64] swap partition size?
by James Parra 12 Mar '05

12 Mar '05

> Hi James, > > Thanks for the reply. > > Is your entire 16GB swap in one partition or file? I was trying to find > out if 2GB was the max for each swap partition. > > eugene It is a 16 Gb partition, however a swapfile would work as well. ~James

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RE: [suse-amd64] swap partition size?
by James D. Parra 12 Mar '05

12 Mar '05

>I can't find a definitive answer to this, so I'll ask here. >I have a dual Opteron server running SLES 8/64. It has 4 GB of RAM. >What is the largest swap partition that Linux supports? I understand the >performance benefits of creating multiple partitions on multiple disks, >but what is the biggest swap partition that Linux will allow or can use? >Would it be different between SLES8/64 vs SLES 8/32? Most of the >documentation I've found seem to suggest that 2GB is the maximum for >each swap partition or file. We have a similar setup. Dual Opterons with eight gigs of ram. The swap is 16gb. We have no problems. Tasks: 87 total, 1 running, 86 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0% us, 0.3% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si Cpu1 : 0.0% us, 0.3% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si Mem: 8119576k total, 8080928k used, 38648k free, 31024k buffers Swap: 16777648k total, 456k used, 16777192k free, 7567684k cached ~James

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swap partition size?
by chu＠tes-mail.jpl.nasa.gov 12 Mar '05

12 Mar '05

Hi List, I can't find a definitive answer to this, so I'll ask here. I have a dual Opteron server running SLES 8/64. It has 4 GB of RAM. What is the largest swap partition that Linux supports? I understand the performance benefits of creating multiple partitions on multiple disks, but what is the biggest swap partition that Linux will allow or can use? Would it be different between SLES8/64 vs SLES 8/32? Most of the documentation I've found seem to suggest that 2GB is the maximum for each swap partition or file. thanks for any information on this. eyc

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Suse 9.3 - which kernel and gcc ?
by Kevin_Gassiot＠veritasdgc.com 12 Mar '05

12 Mar '05

Saw the announcment about the imminent release of Suse 9.3 using the 2.6.11 kernel. Can you tell me which version of gcc will be packaged with this release ? I am looking for gcc 3.4.3 ( I know I can download and build it, I am just curious about what will be packaged :) What is the official release date for this ? Thanks, Kevin Kevin Gassiot Advanced Systems Group Visualization Systems Support Veritas DGC 10300 Town Park Dr. Houston, Texas 77072 832-351-8978 kevin_gassiot(a)veritasdgc.com

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Install hangs
by Ivan Popivanov 11 Mar '05

11 Mar '05

Hi, AMD64, Gigabyte GA-K8NF motherboard, ATI x700 on PCI Express. The 64 bit install hangs when it tries to switch to graphic mode. Changing the resolution doesn't help. If I install in text mode there are no problems with the install, however,. I couldn't install the graphics driver from ATI after the install - similar problem as with the install. sax2 does not show any windows, just a white rectangle where the window is supposed to be. On the same machine the 32 bit install run smoothly in graphic mode and after that following the instructions to install the ATI drivers worked as well. Obviously it's a problem with the 64 bit setup. Is there a fix for that? If there is no fix, I can help debugging the problem on my machine, really want to get the 64 bit SUSE running ;-) Thanks in advance! Ivan

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What is this
by David 11 Mar '05

11 Mar '05

I have been trying to build the xmms from src.rpm. I am getting this result. error: Failed build dependencies: texinfo is needed by xmms-1.2.10-56.1 I have search the SuSE rpm's and descriptions and have not found any reference to this. This is only my second installtion of SuSE and I have not seen this before. David

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HOWTO merge PatchCD and remote install files
by Ron Lau 11 Mar '05

11 Mar '05

HELP! I need the patch CD to install 9.2 on an AMD with sata, but I don't have a DVD drive so I need to use my NFS server. How do I merge the patchCD with the 9.2 install files so that I can install from the nfs server and use the PatchCD kernel? -- R.

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