Re: [PATCH] hugetlb: Add nohugepages parameter to prevent hugepages creation

From: Guilherme G. Piccoli
Date: Tue Oct 15 2019 - 10:09:59 EST

On 10/15/19 11:05 AM, Michal Hocko wrote:
On Tue 15-10-19 10:58:36, Guilherme G. Piccoli wrote:
On 10/15/19 9:18 AM, Michal Hocko wrote:
I do agree with Qian Cai here. Kdump kernel requires a very tailored
environment considering it is running in a very restricted
configuration. The hugetlb pre-allocation sounds like a tooling problem
and should be fixed at that layer.

Hi Michal, thanks for your response. Can you suggest me a current way of
preventing hugepages for being created, using userspace? The goal for this
patch is exactly this, introduce such a way.

Simply restrict the environment to not allocate any hugepages? Kdump
already controls the kernel command line and it also starts only a very
minimal subset of services. So who is allocating those hugepages?
sysctls should be already excluded by default as Qian mentioned.

OK, thanks Michal and Qian, I'll try to make things work from kdump perspective. The trick part is exactly preventing the sysctl to get applied heh