Re: [PATCH 1/5] mm: compaction: Remove redundant VM_BUG_ON() in compact_zone()

[Andrew Morton]

On Tue, 10 Jan 2023 13:37:57 +0000 Matthew Wilcox <willy@xxxxxxxxxxxxx> 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?