Hi Kirill, On Thu, Sep 10, 2020 at 6:01 PM Kirill A. Shutemov <kirill.shute...@linux.intel.com> wrote: > > 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 <vij...@linux.microsoft.com> > > Cc: sta...@vger.kernel.org > > NAK. It would override min_free_kbytes set by user.
Hi Kirill, Thank you for looking into this. How is this different from when khugepaged modifies it? echo always >/sys/kernel/mm/transparent_hugepage/enabled Which results in: start_stop_khugepaged set_recommended_min_free_kbytes Which will also adjust min_free_kbytes according to hugepaged requirement? This bug that Vijay described is another hot-plug related issue that we have found on our system where we perform memory hot add and hot remove on every reboot. Thank you, Pasha