[opensuse] 10.3 kernel default vs. SMP
Hello Probably a stupid question: I thought that recent 2.6 kernels make the need for a SMP and non-SMP kernel obsolete. Maybe my memory is playing tricks again. The reason I ask is the on some PCs, 10.3 installs kernel 2.6.22.5-31-default, while on others it installs 2.6.22.5-31-SMP. In both cases the install was let do whatever it wanted in selecting the kernel version. Have I missed the obvious? Again? -- Roger Oberholtzer OPQ Systems / Ramböll RST Ramböll Sverige AB Kapellgränd 7 P.O. Box 4205 SE-102 65 Stockholm, Sweden Office: Int +46 8-615 60 20 Mobile: Int +46 70-815 1696 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer <roger@opq.se> writes:
Hello
Probably a stupid question: I thought that recent 2.6 kernels make the need for a SMP and non-SMP kernel obsolete. Maybe my memory is playing tricks again. The reason I ask is the on some PCs, 10.3 installs kernel 2.6.22.5-31-default, while on others it installs 2.6.22.5-31-SMP. In both cases the install was let do whatever it wanted in selecting the kernel version. Have I missed the obvious? Again?
Are you sure it is the SMP kernel and not the bigsmp one? There's no explicit SMP one anymore. Please run "rpm -qa 'kernel-*'" and check what is installed, Andreas -- Andreas Jaeger, Director Platform / openSUSE, aj@suse.de SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg) Maxfeldstr. 5, 90409 Nürnberg, Germany GPG fingerprint = 93A3 365E CE47 B889 DF7F FED1 389A 563C C272 A126
On Thu, 2008-01-17 at 13:28 +0100, Andreas Jaeger wrote:
Are you sure it is the SMP kernel and not the bigsmp one? There's no explicit SMP one anymore.
The system is used in a road measurement vehicle, so they are not always handy. I got the info over the phone. When the user said "big SMP", I thought big meant the case of the letters. One hears what one wants to hear. The system has 4GB of RAM. I guess that is why it uses the -BIGSMP kernel? The reason this came up was that I stopped worrying about supplying an -SMP version of a local device driver in our packages. Life was getting simple: only the -default kernel was needed. That didn't last so long. Now I need to dig up a system sunning a -BIGSMP kernel to compile the driver for the package. That's the hard part. -- Roger Oberholtzer OPQ Systems / Ramböll RST Ramböll Sverige AB Kapellgränd 7 P.O. Box 4205 SE-102 65 Stockholm, Sweden Office: Int +46 8-615 60 20 Mobile: Int +46 70-815 1696 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Thu, Jan 17, 2008 at 02:02:41PM +0100, Roger Oberholtzer wrote:
On Thu, 2008-01-17 at 13:28 +0100, Andreas Jaeger wrote:
Are you sure it is the SMP kernel and not the bigsmp one? There's no explicit SMP one anymore.
The system is used in a road measurement vehicle, so they are not always handy. I got the info over the phone. When the user said "big SMP", I thought big meant the case of the letters. One hears what one wants to hear.
The system has 4GB of RAM. I guess that is why it uses the -BIGSMP kernel?
Correct. "bigsmp" is what is in the uname line.
The reason this came up was that I stopped worrying about supplying an -SMP version of a local device driver in our packages. Life was getting simple: only the -default kernel was needed. That didn't last so long. Now I need to dig up a system sunning a -BIGSMP kernel to compile the driver for the package. That's the hard part.
The bigsmp kernel can run on all machines with PAE (Page Address Extensions), which is most of todays hardware. So you can likely just install it and run it ;) Ciao, Marcus -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Thursday 2008-01-17 at 14:02 +0100, Roger Oberholtzer wrote:
The reason this came up was that I stopped worrying about supplying an -SMP version of a local device driver in our packages. Life was getting simple: only the -default kernel was needed. That didn't last so long. Now I need to dig up a system sunning a -BIGSMP kernel to compile the driver for the package. That's the hard part.
Notice that the default kernel is also an SMP kernel, so you may need to compile two versions: smp and bigsmp versions. There is no "no smp" version now. I must be one of the few people on earth running a machine with a single, non smp, processor, so I usually recompile the kernel to suit. O:-) - -- Cheers, Carlos E. R. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) iD8DBQFHj1wVtTMYHG2NR9URAgwUAJ4rfjRFppWaUTuPUsb+JoRAN+2l/gCcDSN7 HPCUMPv7lkeB//YGkC+BD0E= =w99q -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
"Carlos E. R." <robin.listas@telefonica.net> writes:
The Thursday 2008-01-17 at 14:02 +0100, Roger Oberholtzer wrote:
The reason this came up was that I stopped worrying about supplying an -SMP version of a local device driver in our packages. Life was getting simple: only the -default kernel was needed. That didn't last so long. Now I need to dig up a system sunning a -BIGSMP kernel to compile the driver for the package. That's the hard part.
Notice that the default kernel is also an SMP kernel, so you may need to compile two versions: smp and bigsmp versions. There is no "no smp" version now.
I must be one of the few people on earth running a machine with a single, non smp, processor, so I usually recompile the kernel to suit. O:-)
You should not see any performance difference, the kernel figures out at runtime whether it's SMP or not and then uses the correct code. Check dmesg for something like: SMP alternatives: switching to UP code SMP alternatives: switching to SMP code Andreas -- Andreas Jaeger, Director Platform / openSUSE, aj@suse.de SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg) Maxfeldstr. 5, 90409 Nürnberg, Germany GPG fingerprint = 93A3 365E CE47 B889 DF7F FED1 389A 563C C272 A126
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Monday 2008-01-21 at 11:18 +0100, Andreas Jaeger wrote:
I must be one of the few people on earth running a machine with a single, non smp, processor, so I usually recompile the kernel to suit. O:-)
You should not see any performance difference, the kernel figures out at runtime whether it's SMP or not and then uses the correct code. Check dmesg for something like: SMP alternatives: switching to UP code SMP alternatives: switching to SMP code
You are right, I do see the first line; I just rebooted the default kernel in noapic mode to check some other thing (Bug 350980), and so I checked what you said. But I also recompile to optimize for the Pentium IV, and some times I dissable some drivers I know I don't use, like pci hotplug - that's if I feel in the mood to search over all the config, there are so many options that oftener I don't dissable anything out of laziness. - -- Cheers, Carlos E. R. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) iD8DBQFHlIxktTMYHG2NR9URAsu/AJ9EhqHGBk1XXtP5MjmjBW7ooPGJsACgk31O nGjH2Q8dxqSYKEE7+obuQuM= =9rS2 -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer <roger@opq.se> writes:
On Thu, 2008-01-17 at 13:28 +0100, Andreas Jaeger wrote:
Are you sure it is the SMP kernel and not the bigsmp one? There's no explicit SMP one anymore.
The system is used in a road measurement vehicle, so they are not always handy. I got the info over the phone. When the user said "big SMP", I thought big meant the case of the letters. One hears what one wants to hear.
The system has 4GB of RAM. I guess that is why it uses the -BIGSMP kernel?
Correct.
The reason this came up was that I stopped worrying about supplying an -SMP version of a local device driver in our packages. Life was getting simple: only the -default kernel was needed. That didn't last so long. Now I need to dig up a system sunning a -BIGSMP kernel to compile the driver for the package. That's the hard part.
We removed the SMP but BIGSMP is still needed and was needed in this case before already on 32-bit x86 systems, Andreas -- Andreas Jaeger, Director Platform / openSUSE, aj@suse.de SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg) Maxfeldstr. 5, 90409 Nürnberg, Germany GPG fingerprint = 93A3 365E CE47 B889 DF7F FED1 389A 563C C272 A126
participants (4)
-
Andreas Jaeger -
Carlos E. R. -
Marcus Meissner -
Roger Oberholtzer