Messages in this thread | | | Subject | Re: [v4] mm: khugepaged: avoid overriding min_free_kbytes set by user | From | Vijay Balakrishna <> | Date | Thu, 17 Sep 2020 10:27:16 -0700 |
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On 9/17/2020 2:28 AM, Michal Hocko wrote: > On Wed 16-09-20 23:39:39, Vijay Balakrishna wrote: >> set_recommended_min_free_kbytes need to honor min_free_kbytes set by the >> user. Post start-of-day THP enable or memory hotplug operations can >> lose user specified min_free_kbytes, in particular when it is higher than >> calculated recommended value. > > I was about to recommend a more detailed explanation when I have > realized that this patch is not really needed after all. Unless I am > missing something. > > init_per_zone_wmark_min ignores the newly calculated min_free_kbytes if > it is lower than user_min_free_kbytes. So calculated min_free_kbytes >= > user_min_free_kbytes. > > Except for value clamping when the value is reduced and this likely > needs fixing. But set_recommended_min_free_kbytes should be fine. >
IIUC, after start-of-day if a user performs - THP disable - modifies min_free_bytes - THP enable above sequence currently wouldn't result in calling init_per_zone_wmark_min.
Thanks, Vijay
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