linux-kernel - Re: [PATCH v3 12/21] slab: remove the do_slab

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Message-ID: <CAJuCfpFaeYyzHirCYUPT0JDeavuq5UGqegW0OMata31XbYGnww@mail.gmail.com>
Date: Wed, 21 Jan 2026 16:57:17 +0000
From: Suren Baghdasaryan <surenb@...gle.com>
To: Hao Li <hao.li@...ux.dev>
Cc: Vlastimil Babka <vbabka@...e.cz>, Harry Yoo <harry.yoo@...cle.com>, 
	Petr Tesarik <ptesarik@...e.com>, Christoph Lameter <cl@...two.org>, David Rientjes <rientjes@...gle.com>, 
	Roman Gushchin <roman.gushchin@...ux.dev>, Andrew Morton <akpm@...ux-foundation.org>, 
	Uladzislau Rezki <urezki@...il.com>, "Liam R. Howlett" <Liam.Howlett@...cle.com>, 
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>, Alexei Starovoitov <ast@...nel.org>, linux-mm@...ck.org, 
	linux-kernel@...r.kernel.org, linux-rt-devel@...ts.linux.dev, 
	bpf@...r.kernel.org, kasan-dev@...glegroups.com
Subject: Re: [PATCH v3 12/21] slab: remove the do_slab_free() fastpath

On Tue, Jan 20, 2026 at 12:30 PM Hao Li <hao.li@...ux.dev> wrote:
>
> On Fri, Jan 16, 2026 at 03:40:32PM +0100, Vlastimil Babka wrote:
> > We have removed cpu slab usage from allocation paths. Now remove
> > do_slab_free() which was freeing objects to the cpu slab when
> > the object belonged to it. Instead call __slab_free() directly,
> > which was previously the fallback.
> >
> > This simplifies kfree_nolock() - when freeing to percpu sheaf
> > fails, we can call defer_free() directly.
> >
> > Also remove functions that became unused.
> >
> > Reviewed-by: Suren Baghdasaryan <surenb@...gle.com>
> > Signed-off-by: Vlastimil Babka <vbabka@...e.cz>
> > ---
> >  mm/slub.c | 149 ++++++--------------------------------------------------------
> >  1 file changed, 13 insertions(+), 136 deletions(-)
> >
>
> Looks good to me.
> Reviewed-by: Hao Li <hao.li@...ux.dev>

There are some hits in the comments on __update_cpu_freelist_fast and
do_slab_free but you remove them later. Nice cleanup!

Reviewed-by: Suren Baghdasaryan <surenb@...gle.com>

>
> --
> Thanks,
> Hao