From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F61F2931FB for ; Thu, 24 Sep 2026 07:26:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790234808; cv=none; b=B4Ro7OlXuuNkO5lFtMSyykhM45l5igxQHpkfQAoo/M4D77yDambLt6eFI4sEF83rOd2e8c7rLOsoMEgjRyCdzZyd+pZIbiz7yIQQA5qK9fCanPDR6jKU9nHOTAJwYpxG9qNfITG0ReeZCBvdOCelidKNdeOAxvpYkWvto+BWnEs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790234808; c=relaxed/simple; bh=TIOaEomzMVcNumYoptoLvcaCB6v5SNlcY+60z2uPGdk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TErRriybcwVR0H3OEPQk2mVOK5f49WgwMSggAvpqjpN42aebsVPHt/eg+UcK5h9dFI1BFIJSghGvZSUsjI5dI1BHTCNaEcDwAokpOo1KuZg1/otVDw67hWYQP5eI9LvJ86ZgS7Yc32keEoCSE/ersfLoTD4o6J3ra6QjK0Jrb+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VHfZfolz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VHfZfolz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E22E1F000FF; Thu, 24 Sep 2026 07:26:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790234807; bh=vU634+Wj0kiQw2ArhkvTeThC3DE1aRI5IxZASPotl1M=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=VHfZfolzleqbPbPN8K5KO0ppPQt0EK9ZpANQ6jYw27vrg6fRixZwA05ydbsfKEkPo 6nLEbD8zPAyIRgS4lapOARz5nMYfm5tKhFuYJc7PVsrOhnIQI9Ajhrl2WA4PGkx8BU yQ3Xe32uy/I5+4v/3BIpZkgaYz8F85CSBm/8JcaZel3TSMZKWR0JZ9kEBNqT1Qt+yV jrxn/G1WGsod1zizhKEZJALmNliX7cu73XJxUng82rF45M3n/zCfSjX/VlqOlVpa0O H8G44jCwUdx3a5AUfY2zCKkhX1RSEW1CCm4e3GBElCcrLlfMbWkwBZO8wqwLEdham1 f+OruzL71z0bA== Message-ID: <728a4a48-a2cc-4e0b-9c35-054ee0c31e78@kernel.org> Date: Thu, 24 Sep 2026 09:26:43 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC 7/8] mm, slab: add slab_tiny boot param Content-Language: en-US To: Harry Yoo Cc: Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Geert Uytterhoeven , Conor Dooley , Damien Le Moal , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260923-slub_tiny_rework-v1-0-a0e66d536eb5@kernel.org> <20260923-slub_tiny_rework-v1-7-a0e66d536eb5@kernel.org> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/23/26 17:45, Vlastimil Babka (SUSE) wrote: > In order to deprecate the CONFIG_SLUB_TINY option, introduce an early > boot param slab_tiny to control the value of slab_tiny_enabled. > > As long as CONFIG_SLUB_TINY is still around and enabled, this boot param > can also override it to be disabled. > > Signed-off-by: Vlastimil Babka (SUSE) > --- > Documentation/admin-guide/kernel-parameters.txt | 4 ++++ > Documentation/admin-guide/mm/slab.rst | 5 +++++ > mm/slub.c | 7 +++++++ > 3 files changed, 16 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 33cd30996e47..0100ab00388a 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -7031,6 +7031,10 @@ Kernel parameters > NUMA kernel object placement which helps with slow > interconnects in NUMA systems. > > + slab_tiny= [MM, EARLY] > + Minimize the slab allocator memory footprint at the > + expense of SMP scalability. > + > slram= [HW,MTD] > > smart2= [HW] > diff --git a/Documentation/admin-guide/mm/slab.rst b/Documentation/admin-guide/mm/slab.rst > index 0beeae71d472..6c005d3de0b2 100644 > --- a/Documentation/admin-guide/mm/slab.rst > +++ b/Documentation/admin-guide/mm/slab.rst > @@ -94,6 +94,11 @@ kdump kernels where scalability is not a concern, but memory has to be > > slab_debug=N > > +Note that for this purpose you can instead use an option that can achieve > +slightly better memory savings (by not creating separate kmalloc-rcl caches):: > + > + slab_tiny=1 > + > You can apply different options to different list of slab names, using blocks > of options. This will enable red zoning for dentry and user tracking for > kmalloc. All other slabs will not get any debugging enabled:: > diff --git a/mm/slub.c b/mm/slub.c > index 4814f025fde5..d672809fa2f6 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -8726,6 +8726,13 @@ void __init kmem_cache_init_late(void) > #endif > } > > +static int __init early_slab_tiny(char *buf) > +{ > + return kstrtobool(buf, &slub_tiny_enabled); ^ slab_tiny_enabled missed a place on a last-minute rename. The version in git is fixed: https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git/log/?h=b4/slub_tiny_rework > +} > + > +early_param("slab_tiny", early_slab_tiny); > + > int do_kmem_cache_create(struct kmem_cache *s, const char *name, > unsigned int size, struct kmem_cache_args *args, > slab_flags_t flags) >