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Subject: Re: Can kfree() sleep at runtime?
To:     Christopher Lameter <cl@linux.com>,
        Matthew Wilcox <willy@infradead.org>
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From:   Jia-Ju Bai <baijiaju1990@gmail.com>
Message-ID: <066df211-4d1e-787b-b89d-31b8827ea7a5@gmail.com>
Date:   Fri, 1 Jun 2018 09:22:00 +0800
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On 2018/5/31 22:30, Christopher Lameter wrote:
> On Thu, 31 May 2018, Matthew Wilcox wrote:
>
>>> Freeing a page in the page allocator also was traditionally not sleeping.
>>> That has changed?
>> No.  "Your bug" being "The bug in your static analysis tool".  It probably
>> isn't following the data flow correctly (or deeply enough).
> Well ok this is not going to trigger for kfree(), this is x86 specific and
> requires CONFIG_DEBUG_PAGEALLOC and a free of a page in a huge page.
>
> Ok that is a very contorted situation but how would a static checker deal
> with that?

I admit that my tool does not follow the data flow well, and I need to 
improve it.
In this case of kfree(), I want know how the data flow leads to my mistake.


Best wishes,
Jia-Ju Bai