Re: [[PATCH]] mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged

From: Kirill A. Shutemov
Date: Thu Sep 10 2020 - 18:01:52 EST

On Thu, Sep 10, 2020 at 01:47:39PM -0700, Vijay Balakrishna wrote:
> When memory is hotplug added or removed the min_free_kbytes must be
> recalculated based on what is expected by khugepaged. Currently
> after hotplug, min_free_kbytes will be set to a lower default and higher
> default set when THP enabled is lost. This leaves the system with small
> min_free_kbytes which isn't suitable for systems especially with network
> intensive loads. Typical failure symptoms include HW WATCHDOG reset,
> soft lockup hang notices, NETDEVICE WATCHDOG timeouts, and OOM process
> kills.
> Fixes: f000565adb77 ("thp: set recommended min free kbytes")
> Signed-off-by: Vijay Balakrishna <vijayb@xxxxxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

NAK. It would override min_free_kbytes set by user.

Kirill A. Shutemov