linux-kernel - Re: [PATCH v2] slab: fix slab accounting imbalance due to defer_deactivate

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Message-ID: <CAADnVQ+H+VLFROjJJYkbaT6ED_ecFzu4eLci1oP9C0kDp7Aa9Q@mail.gmail.com>
Date: Fri, 24 Oct 2025 11:08:51 -0700
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: Harry Yoo <harry.yoo@...cle.com>
Cc: Vlastimil Babka <vbabka@...e.cz>, Andrew Morton <akpm@...ux-foundation.org>, 
	Christoph Lameter <cl@...two.org>, David Rientjes <rientjes@...gle.com>, 
	Roman Gushchin <roman.gushchin@...ux.dev>, Alexei Starovoitov <ast@...nel.org>, linux-mm <linux-mm@...ck.org>, 
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] slab: fix slab accounting imbalance due to defer_deactivate_slab()

On Fri, Oct 24, 2025 at 2:36 AM Harry Yoo <harry.yoo@...cle.com> wrote:
>
> >
> > Note that deactivate_slab() contains VM_BUG_ON(!old.frozen);
> > we would have seen this triggered if we were passing unfrozen slabs to
> > (defer_)deactivate_slab(). I assume it's also why the "unlucky, discard"
> > code marks it frozen before calling defer_deactivate_slab() (and this patch
> > removes that).

Yes, exactly, since that's what deactivate_slab() wants to see.

> > So I think we're fine?
>
> Yes.

All my concerns were answered. I guess I understand it enough now to:
Acked-by: Alexei Starovoitov <ast@...nel.org>