Given a page, How to get the NUMA node id of this page
Hi all, I am working on a checkpoint/Restart Linux kernel module. Wherein, a process sends a request to this module to checkpoint itself. In this process information about the process is stored in a file, which is used later on to restart the process. Now when this module is storing the information related to pages (of the process) in a file, we also want to know on which NUMA node this page was assigned Can you suggest what will be the best way to get this data (page to NUMA node mapping) I tried using page_to_nid(page), but I am not really sure it gives me correct value. (Like, I am working on linux 2.6.32, 64 bit machine with 16 cores and there are 4 NUMA nodes (4 cores on each) on it, but this function returns 32 when called) Thanks, Ajay
On Fri, 30 Aug 2013 02:43:00 +0800, ajay saini said:
I am working on a checkpoint/Restart Linux kernel module.
Have you looked at the already existing checkpoint/restart support? (and C/R is a lot harder to get right than you think - turns out you need all sorts of infrastructure. The various namespaces support, for instance, are to a large degree to allow C/R to work right. For example, you need PID namespaces so you can properly do C/R of a process that has done a getpid() call - because you need to restart it with the same PID that it had at checkpoint time. in init/Kconfig: config CHECKPOINT_RESTORE bool "Checkpoint/restore support" if EXPERT default n help Enables additional kernel features in a sake of checkpoint/restore. In particular it adds auxiliary prctl codes to setup process text, data and heap segment sizes, and a few additional /proc filesystem entries. If unsure, say N here. Enjoy, and don't re-invent the wheel.
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ajay saini -
Valdis.Kletnieks＠vt.edu