Hi, Bryce Harrington wrote: > I have a question about how sar should operate during hotplug > operations. Consider the following situation: > > 1. offline a cpu > ... > > 2. start sar > ... > > 3. online the cpu > ... > > 4. The sar output does not display the newly onlined CPU, and > continues to only show cpu's 0, 1, and 2. > > > I'm wondering if this is intended behavior? When sar is started with > all the CPU's onlined, and a cpu is offlined when it runs, then it will > display 'nan' for that cpu, until it comes back online; this is fine, > since you can see in the output that a cpu is missing. However if the > cpu is brought online after sar starts, then the sar output is not > really providing complete information on the system. How do you think > sar ought to behave in this situation? > No, this is not really intended behavior. In fact sar is just not "hotplug CPU compliant" and has never been tested on such hardwares... Anyway I'm really interested to update it so that it can take into account CPU that get off- or onlined on the fly. But I need to know how files like /proc/stat for example are changed when a CPU is offlined or onlined. I would appreciate to get some info about that. Regards, -- Sébastien Godard (sysstat <at> wanadoo.fr) http://perso.orange.fr/sebastien.godard/
