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Fri, 13 Nov 2026 00:52:24 -0800 (PST) Received: from [172.22.0.2] ([50.175.87.158]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2ee0f75b472sm6940845ad.19.2026.11.13.00.52.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Nov 2026 00:52:24 -0800 (PST) Date: Fri, 13 Nov 2026 00:52:19 -0800 From: Chris Down To: Harry Yoo Cc: Kees Cook , Vlastimil Babka , Andrew Morton , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Marco Elver , GONG Ruiqi , Jonathan Corbet , linux-mm@kvack.org, linux-hardening@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v2 3/6] mm/slab: Support disabling SLAB_BUCKETS at boot In-Reply-To: References: <9a68a4d95830352ad3821437c2e22c30a673055b.1793253633.git.chris@chrisdown.name> <202610302115.8C7AD110@keescook> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Message-ID: <20261113005219.f954ab03e886b1c3@chrisdown.name> User-Agent: Mutt/2.4.3 (cc9e3943) (2026-10-09) Hi Harry, Harry Yoo writes: >A gentle ping to Kees to hear his thoughts on having a bit more >coarse grained boot parameter e.g.) `slab_hardening=` to specify >how much performance/memory is worth sacrificing for enhanced security. For what it's worth, I'd still prefer to keep slab_buckets= and kmalloc_partition= as they are. Each one maps onto one config option and one cost that you can reason about on its own (about 1 MiB vs 18 MiB in your numbers). If we want slab_hardening= as well, it seems easy enough to add later on top, as a way to set the defaults for the individual parameters. So I don't think it needs to block this. I'd like to hear what Kees and Marco think too, though. Thanks! Chris