Messages in this thread | | | Date | Mon, 15 Jul 2019 06:06:48 -0700 | From | Matthew Wilcox <> | Subject | Re: [PATCH] mm: page_alloc: document kmemleak's non-blockable __GFP_NOFAIL case |
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On Sun, Jul 14, 2019 at 08:47:07PM -0700, Yang Shi wrote: > > > On 7/13/19 2:25 PM, Matthew Wilcox wrote: > > 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. > > Do you mean kmemleak internal allocation? It would fail even though > __GFP_NOFAIL is passed in if GFP_NOWAIT is specified. Currently buddy > allocator will not retry if the allocation is non-blockable.
Actually it sets off a warning. Which is the right response from the core mm code because specifying __GFP_NOFAIL and __GFP_NOWAIT makes no sense.
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