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Date: Sun, 9 Jun 2024 14:03:41 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Leesoo Ahn <lsahn@ooseel.net>
Cc: Leesoo Ahn <lsahn@wewakecorp.com>, linux-mm@kvack.org,
 linux-kernel@vger.kernel.org, Mike Rapoport <rppt@kernel.org>
Subject: Re: [PATCH] mm: sparse: clarify a variable name and its value
Message-Id: <20240609140341.14ba3a1c62029771d60059ed@linux-foundation.org>
In-Reply-To: <20240608152114.867961-1-lsahn@wewakecorp.com>
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On Sun,  9 Jun 2024 00:21:14 +0900 Leesoo Ahn <lsahn@ooseel.net> wrote:

> Setting 'limit' variable to 0 might seem like it means "no limit". But
> in the memblock API, 0 actually means the 'MEMBLOCK_ALLOC_ACCESSIBLE'
> enum, which limits the physical address range based on
> 'memblock.current_limit'. This can be confusing.

Does it?  From my reading, this meaning applies to the range end
address, in memblock_find_in_range_node()?  If your interpretation is
correct, this should be documented in the relevant memblock kerneldoc.

> To make things clearer, I suggest renaming the variable to
> 'limit_or_flag'. This name shows that the variable can either be a
> number for limits or an enum for a flag. This way, readers will easily
> understand what kind of value is being passed to the memblock API and
> how it works without needing to look into the API details.
> 

I think I'll cc Mike and run away ;)