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Wed, 5 Feb 2025 10:51:47 -0800 (PST) Date: Wed, 5 Feb 2025 10:51:47 -0800 (PST) From: "Christoph Lameter (Ampere)" To: Jessica Clarke cc: Maciej Wieczor-Retman , luto@kernel.org, xin@zytor.com, kirill.shutemov@linux.intel.com, palmer@dabbelt.com, tj@kernel.org, andreyknvl@gmail.com, brgerst@gmail.com, ardb@kernel.org, dave.hansen@linux.intel.com, jgross@suse.com, will@kernel.org, akpm@linux-foundation.org, arnd@arndb.de, corbet@lwn.net, dvyukov@google.com, richard.weiyang@gmail.com, ytcoode@gmail.com, tglx@linutronix.de, hpa@zytor.com, seanjc@google.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu, justinstitt@google.com, jason.andryuk@amd.com, glider@google.com, ubizjak@gmail.com, jannh@google.com, bhe@redhat.com, vincenzo.frascino@arm.com, rafael.j.wysocki@intel.com, ndesaulniers@google.com, mingo@redhat.com, catalin.marinas@arm.com, junichi.nomura@nec.com, nathan@kernel.org, ryabinin.a.a@gmail.com, dennis@kernel.org, bp@alien8.de, kevinloughlin@google.com, morbo@google.com, dan.j.williams@intel.com, julian.stecklina@cyberus-technology.de, peterz@infradead.org, kees@kernel.org, kasan-dev@googlegroups.com, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, linux-doc@vger.kernel.org Subject: Re: [PATCH 00/15] kasan: x86: arm64: risc-v: KASAN tag-based mode for x86 In-Reply-To: Message-ID: <72837fcd-97a8-c213-0098-c8f308c3415d@gentwo.org> References: <8bd9c793-aac6-a330-ea8f-3bde0230a20b@gentwo.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-1508829946-1738781507=:2407083" X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: AE830140003 X-Stat-Signature: xefun6qza8f167ay48bisckixf57zaxd X-HE-Tag: 1738788386-583495 X-HE-Meta: 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 dgUhVvpe Kgu4dNiNEpq2nv/hFFIw1IOMUXebM5rQQCTTaOeKVjnpgu+CMjSetB2QE16IOl9Ygw8UwMHfT2K53vH7GTMnT/DriSmUfS2J/xvJK1Twtl1DzVfQ7kl7CBkez18YnPPKehkbNhULkUhD7EFYw9hO+Bmd6I8yqYjATf6OcwTEYxt9WzFL1yBuCOnvrk0nK755KIlNja106P2WnCHmzkDPHnRPpgV6EswI/tVxTphfK5YuKo41U4zzlpyxPYUpCXO4hSs6ykjGuFWYCJ4KXxA6YOy4LEfduSQ8i1yJ9YECgLWDWcamIYbCMPyvhg0Kc0aAzGlnP3vH2MXX3ELkQydzhn55xsiDbD7Xd33+9BXyhVs10kXDAkKM/KfFu401wmAoiCYAH1nZtMHJc8WRKrQMwjl4xkN1G9Aq9hPfVwqmSf35Dvb4mwisGzXUPrFvDjBbGDVVm X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1508829946-1738781507=:2407083 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT On Tue, 4 Feb 2025, Jessica Clarke wrote: > It’s not “no performance penalty”, there is a cost to tracking the MTE > tags for checking. In asynchronous (or asymmetric) mode that’s not too On Ampere Processor hardware there is no penalty since the logic is build into the usual read/write paths. This is by design. There may be on other platforms that cannot do this. --8323329-1508829946-1738781507=:2407083--