Re: [PATCH v3 1/5] mm: page_alloc: remain memblock_next_valid_pfn() when CONFIG_HAVE_ARCH_PFN_VALID is enable
From: Wei Yang
Date: Mon Apr 02 2018 - 04:12:55 EST
On Wed, Mar 28, 2018 at 05:49:23PM +0800, Jia He wrote:
>On 3/28/2018 5:18 PM, Wei Yang Wrote:
>> Oops, I should reply this thread. Forget about the reply on another thread.
>> On Sun, Mar 25, 2018 at 08:02:15PM -0700, Jia He wrote:
>> > Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns
>> > where possible") optimized the loop in memmap_init_zone(). But it causes
>> > possible panic bug. So Daniel Vacek reverted it later.
>> Why this has a bug? Do you have some link about it?
>> If the audience could know the potential risk, it would be helpful to review
>> the code and decide whether to take it back.
>Paul firstly submit a commit b92df1de5 to improve the loop in
>And Daniel tried to fix a bug_on panic issue on X86 in commit 864b75f9d6b
>there is evidence that this bug_on was caused by b92df1de5 .
>But things didn't get better, 864b75f9d6b caused booting hang issue on
>So maintainer decided to reverted both b92df1de5 and 864b75f9d6b
I took some time to look into the discussion, while the root cause seems not
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