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Date:   Thu, 7 Sep 2023 05:10:36 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Peng Zhang <zhangpeng.00@bytedance.com>
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Subject: Re: [PATCH] maple_tree: use GFP_KERNEL on mas_node_count
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On Thu, Sep 07, 2023 at 12:02:02PM +0800, Peng Zhang wrote:
> 
> 
> 在 2023/9/7 11:49, Matthew Wilcox 写道:
> > On Thu, Sep 07, 2023 at 12:39:14PM +0900, 심재선 wrote:
> > > Use GFP_KERNEL on mas_node_count instead of GFP_NOWAIT | __GFP_NOWARN
> > > in order to allow memory reclaim.
> There are many paths that call maple tree's mas_node_count(). Some paths
> cannot reclaim memory.

Right ... but we should be handling the ENOMEM inside the maple tree and
allocating some nodes with GFP_KERNEL instead of failing fork().

> > What testing did you do of this patch?  In particular, did you try it
> > with lockdep enabled?