Re: [PATCH 5/5] hugetlbfs: Limit wait time when trying to share huge PMD

From: Matthew Wilcox
Date: Wed Sep 11 2019 - 11:15:02 EST

On Wed, Sep 11, 2019 at 04:05:37PM +0100, Waiman Long wrote:
> When allocating a large amount of static hugepages (~500-1500GB) on a
> system with large number of CPUs (4, 8 or even 16 sockets), performance
> degradation (random multi-second delays) was observed when thousands
> of processes are trying to fault in the data into the huge pages. The
> likelihood of the delay increases with the number of sockets and hence
> the CPUs a system has. This only happens in the initial setup phase
> and will be gone after all the necessary data are faulted in.

Can;t the application just specify MAP_POPULATE?