Re: [PATCH] mm: page_alloc: document kmemleak's non-blockable __GFP_NOFAIL case

From: Matthew Wilcox
Date: Sat Jul 13 2019 - 17:25:58 EST


On Sat, Jul 13, 2019 at 04:49:04AM +0800, Yang Shi wrote:
> When running ltp's oom test with kmemleak enabled, the below warning was
> triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
> passed in:

There are lots of places where kmemleak will call kmalloc with
__GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM (including the XArray code, which
is how I know about it). It needs to be fixed to allow its internal
allocations to fail and return failure of the original allocation as
a consequence.