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Date:   Tue, 10 Jan 2023 15:25:32 -0800
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Baolin Wang <baolin.wang@linux.alibaba.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] mm: compaction: Remove redundant VM_BUG_ON() in
 compact_zone()
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On Tue, 10 Jan 2023 13:37:57 +0000 Matthew Wilcox <willy@infradead.org> wrote:

> On Tue, Jan 10, 2023 at 09:36:18PM +0800, Baolin Wang wrote:
> > The compaction_suitable() will never return values other than COMPACT_SUCCESS,
> > COMPACT_SKIPPED and COMPACT_CONTINUE, so after validation of COMPACT_SUCCESS
> > and COMPACT_SKIPPED, we will never hit other unexpected case. Thus remove
> > the redundant VM_BUG_ON() validation for the return values of compaction_suitable().
> 
> I don't understand why we'd remove this check.

Well, just from code inspection it serves no purpose.

Such an assertion might be useful during early code development, but I
think we can consider compaction_suitable() to adequately debugged by
now?