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From: Lance Yang <lance.yang@linux.dev>
To: ye.liu@linux.dev
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Subject: Re: [PATCH v2] mm/khugepaged: use ALIGN helpers for PMD alignment
Date: Thu,  9 Apr 2026 11:12:42 +0800
Message-Id: <20260409031242.91778-1-lance.yang@linux.dev>
In-Reply-To: <20260409014323.2385982-1-ye.liu@linux.dev>
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On Thu, Apr 09, 2026 at 09:43:22AM +0800, Ye Liu wrote:
>From: Ye Liu <liuye@kylinos.cn>
>
>PMD alignment in khugepaged is currently implemented using a mix of
>rounding helpers and open-coded bitmask operations.
>
>Use ALIGN() and ALIGN_DOWN() consistently for PMD-sized address range
>alignment, matching the preferred style for address and size handling.

One more spot in madvise_collapse():

hend = min(hend, vma->vm_end & HPAGE_PMD_MASK);

Maybe switch that one to ALIGN_DOWN() as well.

And there is also in try_collapse_pte_mapped_thp():

unsigned long haddr = addr & HPAGE_PMD_MASK;

Just a thought :)
Lance