Messages in this thread | | | Date | Mon, 6 Feb 2023 10:42:46 +0100 (CET) | From | Christoph Lameter <> | Subject | Re: [PATCH 3/5] mm/vmstat: use cmpxchg loop in cpu_vm_stats_fold |
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On Fri, 3 Feb 2023, Marcelo Tosatti wrote:
> > Isnt there some lock/serializtion to stall the kernel until you are done? > > Not that i know of. Anyway, an additional datapoint is: > > "Software defined PLC" > (https://www.redhat.com/en/blog/software-defined-programmable-logic-controller-introduction), > applications > can perform system calls in their time sensitive loop. > > One example of an opensource software is OpenPLC. > > One would like to avoid interruptions for those cases as well.
Well allowing sytem calls during "time sensitiveness" implies it is not that sensitive to vmstat updates which have a smaller impact than system calls.
Unless we are talking about virtual system calls like gettimeofday or clock_gettime. These do not enter the kernel if configured correctly.
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