Thanks Nitin for your inputs.

On 5/28/2021 5:22 AM, Nitin Gupta wrote:

quoted

First, Does the user doing the above steps are valid?
If yes, then we should guarantee to the user that proactive compaction
atleast tried to run when the user changed the proactiveness.
If not, I feel, we should document that 'once user changed the
compaction_proactiveness, he need to wait atleast
HPAGE_FRAG_CHECK_INTERVAL_MSEC before considering that the value he
tried to set is effective and proactive compaction tried to run on that'.
Doesn't this seem okay?

Proactive compaction does not guarantee if the kernel will be able to achieve
fragmentation targets implied from the compaction_proactiveness sysctl. It also
does not guarantee how much time it will take to reach desired fragmentation
levels (if at all possible). 

Shouldn't we add these lines in the Documentation. Will raise a patch If
it is fine.

Maybe add a Kconfig parameter for setting
HPAGE_FRAG_CHECK_INTERVAL_MSEC to say 1msec?

I really don't have an use case to make the
HPAGE_FRAG_CHECK_INTERVAL_MSEC as config option. But should we make it
as Kconfig option and let the user decide how aggressively proactive
compaction should do the job of system defragmentation in his system?
Selection will be limited in the range of 10msec to 500msec, defaults to
500msec.

--Thanks

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