linux-kernel - [QUESTION] xas_reload() in iter_xarray_populate

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Message-Id: <20250526063524.22597-1-dev.jain@arm.com>
Date: Mon, 26 May 2025 12:05:24 +0530
From: Dev Jain <dev.jain@....com>
To: david@...hat.com,
	ziy@...dia.com,
	willy@...radead.org,
	dhowells@...hat.com,
	hughd@...gle.com
Cc: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	ryan.roberts@....com,
	aneesh.kumar@...nel.org
Subject: [QUESTION] xas_reload() in iter_xarray_populate_pages()

Hello all,

After doing an xas_load() and xas_retry(), we take neither a reference nor a lock
on the folio, and we do an xas_reload(). Is this just to reduce the time window
for a race?

If the above is true, then, there is a negligible window between xas_load() and
xas_reload(), because only xas_retry() exists between them, so why to even reload()?

Thanks,
Dev