On 16/09/10 15:41, Brice Goglin wrote:
Le 16/09/2010 06:10, Alexey Kardashevskiy a écrit :2. The HWLOC expects numa nodes to be numbered consecutively, like 1-2-3-4-5.... However this is not necessary true for PowerPC with LPARs or on systems with numa hotswap (do they exist? don't know).Yes, I've never implemented any sparse-aware code since I haven't ever seen sparse-numbered system :)
I posted tgz - you may take a look :)
- where do I put IBM-specific code?Is the device tree linux-specific ? If so, it can stay in linux file as long as it's not 30k lines :) We already have both sysfs and /proc/cpuinfo code there anyway.
It is powerpc-specific. It is mapped from the system firmware (aka bios) by the powerpc kernel. However it is just a folder within /proc so it is usual linux folder. But PowerPC might be not the only architecture which uses the same pathname for the same thing.
See my note above about the system firmware :) Almost every powerpc system has device-tree no matter which OS you run on it (sony ps3 is probably the only exception). /proc/device-tree is the only source for sysfs on powerpc linux.- may be there is a better way to detect that no cache info was fetched from sysfsThat's something that's not clear to me yet. There will likely be other cases in the future where we will fetch some info from different backends, and merging them may not be easy. Do you think the device tree generally contains more information than sysfs? If so, we could start by disabling cache info from sysfs when a device-tree is found, and maybe have a way to change that default (we already have a hidden en variable to use cpuinfo when sysfs is available).
- is the coding style ok? :-)It doesn't look bad.
The current topology-linux.c consist of several coding styles so I could not detect which one is primary :)
One question though: Is the device tree completely save-able for external reuse? We like being able to save /proc and /sys so as to debug distant machines locally. Doing the same for the device tree would be great. If so, could you send a tarball of a machine with sparse-numa numbers? And we'll likely make gather-topology.sh store it too.
I am attaching a result of the "tar czf 256cpu_device_tree.tgz /proc/device-tree/" command. Looks good. TAR complained multiple times that "file changed as we read it" though.
ps: I get every mail twice. I know I screwed up with subscription but how do I or somebody fix that? I need to have only a...@au1.ibm.com subscribed. Thank you :)
256cpu_device_tree.tgz
Description: application/compressed-tar
