linux-kernel - Re: [PATCH 1/2] mm/zsmalloc: fix class per-fullness zspage counts

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Message-ID: <20240628005523.GC15925@google.com>
Date: Fri, 28 Jun 2024 09:55:23 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Chengming Zhou <chengming.zhou@...ux.dev>
Cc: minchan@...nel.org, senozhatsky@...omium.org, akpm@...ux-foundation.org,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] mm/zsmalloc: fix class per-fullness zspage counts

On (24/06/27 15:59), Chengming Zhou wrote:
> We always use insert_zspage() and remove_zspage() to update zspage's
> fullness location, which will account correctly.
> 
> But this special async free path use "splice" instead of remove_zspage(),
> so the per-fullness zspage count for ZS_INUSE_RATIO_0 won't decrease.
> 
> Fix it by decreasing when iterate over the zspage free list.

So this doesn't fix anything.  ZS_INUSE_RATIO_0 is just a "placeholder"
which is never used anywhere.

We can land this patch, if you insist/prefer, but it's some sort of
a NOOP, essentially (in a sense that it has no visible effects).