On Mon, Nov 23, 2020 at 01:52:13PM -0800, Mike Kravetz wrote: > On 11/22/20 11:38 PM, Michal Hocko wrote: > > On Fri 20-11-20 09:45:12, Mike Kravetz wrote: > >> Not sure if I agree with that last statement. Database and virtualization > >> use cases from my employer allocate allocate hugetlb pages after boot. It > >> is shortly after boot, but still not from boot/kernel command line. > > > > Is there any strong reason for that? > > The reason I have been given is that it is preferable to have SW compute > the number of needed huge pages after boot based on total memory, rather > than have a sysadmin calculate the number and add a boot parameter.
Oh, I remember this bug! I think it was posted publically, even. If the sysadmin configures, say, 90% of the RAM to be hugepages and then a DIMM fails and the sysadmin doesn't remember to adjust the boot parameter, Linux does some pretty horrible things and the symptom is "Linux doesn't boot".
