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smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com; spf=pass smtp.mailfrom=sk.com; arc=none smtp.client-ip=166.125.252.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-c2dff70000001609-83-68df2b06f003 Date: Fri, 3 Oct 2025 10:46:41 +0900 From: Byungchul Park To: Mark Brown Cc: linux-kernel@vger.kernel.org, kernel_team@skhynix.com, torvalds@linux-foundation.org, damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, jack@suse.cz, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com, harry.yoo@oracle.com, chris.p.wilson@intel.com, gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com, boqun.feng@gmail.com, longman@redhat.com, yunseong.kim@ericsson.com, ysk@kzalloc.com, yeoreum.yun@arm.com, netdev@vger.kernel.org, matthew.brost@intel.com, her0gyugyu@gmail.com, corbet@lwn.net, catalin.marinas@arm.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, sumit.semwal@linaro.org, gustavo@padovan.org, christian.koenig@amd.com, andi.shyti@kernel.org, arnd@arndb.de, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, rppt@kernel.org, surenb@google.com, mcgrof@kernel.org, petr.pavlu@suse.com, da.gomez@kernel.org, samitolvanen@google.com, paulmck@kernel.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com, josh@joshtriplett.org, urezki@gmail.com, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang@linux.dev, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, chuck.lever@oracle.com, neil@brown.name, okorniev@redhat.com, Dai.Ngo@oracle.com, tom@talpey.com, trondmy@kernel.org, anna@kernel.org, kees@kernel.org, bigeasy@linutronix.de, clrkwllms@kernel.org, mark.rutland@arm.com, ada.coupriediaz@arm.com, kristina.martsenko@arm.com, wangkefeng.wang@huawei.com, kevin.brodsky@arm.com, dwmw@amazon.co.uk, shakeel.butt@linux.dev, ast@kernel.org, ziy@nvidia.com, yuzhao@google.com, baolin.wang@linux.alibaba.com, usamaarif642@gmail.com, joel.granados@kernel.org, richard.weiyang@gmail.com, geert+renesas@glider.be, tim.c.chen@linux.intel.com, linux@treblig.org, alexander.shishkin@linux.intel.com, lillian@star-ark.net, chenhuacai@kernel.org, francesco@valla.it, guoweikang.kernel@gmail.com, link@vivo.com, jpoimboe@kernel.org, masahiroy@kernel.org, brauner@kernel.org, thomas.weissschuh@linutronix.de, oleg@redhat.com, mjguzik@gmail.com, andrii@kernel.org, wangfushuai@baidu.com, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-i2c@vger.kernel.org, linux-arch@vger.kernel.org, linux-modules@vger.kernel.org, rcu@vger.kernel.org, linux-nfs@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: Re: [PATCH v17 09/47] arm64, dept: add support CONFIG_ARCH_HAS_DEPT_SUPPORT to arm64 Message-ID: <20251003014641.GF75385@system.software.com> References: <20251002081247.51255-1-byungchul@sk.com> <20251002081247.51255-10-byungchul@sk.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA02Sa0yTZxTH97zv817orHlXJbxqlrjiosHJ5qLJMXFkt4QnWVyW+EXdB63w Zm3klhZBNpd1CFjdjTQrhorKRWrlqjQyqYLIpNp0pEUE6iytmKIQ6EiwxSCFriUz89vvec4/ v3Nycnha0cCu5zV5hZI2T5WjZGVYFlpVv43bGlB/MP9QgJEfezFEwgYMNe0tLBg6qhnwtDUj CEQMCMq7YhiWjA4OwguPOIh1OxBUDRppeH5lmYXpP+cQmMaDLEz1Z0IocIOB2NgzCkbnZxBY gssUBHtPIrhQb2NhccBNwxmTB0G3tZSFicprNAwFV8ODyCwLocEaCk40tLPQ9djOweB0lAJf lZGCgOUpBldlPQVVV1Pg7JlJCkytNyhYsDRxYNG/C2cHhhh4YjVzEB3fDrHafBj7zYShLeRm wOkfYWD6qZGFwN0KBv7QP+ag42E/AoM9gqGu4iKG6vM+Fm52OzEYlsIIhuw1LPx85RoD/pZY fA+9LgbuN3swtD/zUuBy3MPgNF/G4La3Mh9nkxflv2LSZOukSPn9JZa0nG9BZPGlEZFw4wma lFfGn2W2YtLommFJl3mMI2U9f3OktuMoKbsTYojNmkYabk5RpG4uwny19YBsd7aUoymStO9n HJKpB0sXuYK/ZMc8pllKj/7hTqMkXhR2iFOdF/Ar9lkn2QRjYZNom3CtMCtsFr3eBTrBa4VU cfhFdzwv42mhboN4KdTOJAprhINi9PID6jTiebkAYvi6JpFRCNVI7Pm9b6WBXHhLdFYHV5gW 0kTv8tRKnhbinmU+8Z0kfCL6f/JRCU6O9+rtvEslPKLgTxJne279N+g68bbViyuRYH5Na35N a/5fW4voJqTQ5BXlqjQ5O9LVJXmaY+lZ+bkdKH66lu+jX19Hc569fUjgkXKVnBT41QpGVaQr ye1DIk8r18oPWX1qhTxbVfKtpM0/qD2aI+n60AYeK1PkH84XZyuEb1SF0hFJKpC0r6oUn7Re j3Y23J4s+GzXGxdF99XCbaltEuKUpZG3R79w7M0cneh/s3n/e+mNWePpu6oOM1mtHL9xZM+X Qf/xT4ePfOfO/Gj/mmKdfUtyVtE9b/QH5Ray+tG+VM+5U0OgfL5Yu2dGMezM3DT5zpOBDDxH bfyl4pRt5M5s8uexc4zjVnNPaUaKvkSJdWrV9jRaq1P9C2cgzuy2AwAA X-Brightmail-Tracker: H4sIAAAAAAAAA02SbUxTZxTH8zz3lWZ3u1aIN+CyrZOYQVCILjm+ZNmyZNwsmWHJ1MQPkwav trwU0moHJou82NigbrWjEFp1FWNF6KADIVRTJKgQRIQKKpFCwVSEyMsyCwRLYS2JmV9Ofuf5 ///nOR8OS8jDVDyr1hyXtBplroKWkbJ9e8pS6GS/KrXFmAhPSzpIWAgaSbjY6KTB2FRNwUBD PQL/ghHBUshGgMG9RkLY3MVAcHmEgTVPF4JKr5kA580SDG9cqzS8vvsvAstEgIaq6RIS5h3n EFgnbQxM30+HWf9tCtZGX2F4tjiDwBFYxRDoOIMgXJkDf9Y00xDq6yegyjKA4MrEKAFTroh4 s2sMgae2lIaXphYCBgMfwtDCPA09lrM0zHovYphz0WAv9VBwyWZGUHa1kYbKS00kuMdvMeB9 vYLBV2nGUN/0A/gdkyT0mmpwZL+I6+9NYKsqw5EyhcHy120My446Bh5e9ZHgKE4EW98gBS9q rQysTKTBmj0fuupfMTD6u4WEhtl+6msLEpcMv5FiXXMrFg2Pw7TovOxEYuitGYnBa2WEaDBF 2rsz84R4uvkX8VrvDC2+XXhCi55FOyk+qBHEC30pots6yoin258zGbsPyfYekXLVekm7/atM mcpbGmIKHsoKByzzuBjNMeUohhX4nYKvdoqOMslvEZpf9q4zzW8VhoeXiSjH8p8LT5Y8ZDmS sQR/JUG4PttIRYWN/GFh5cYQLkcsy/EgBNvUUY+cr0ZCe0UnGfVw/AahpzqwzgSfJAyvTq/7 CT4yZ5WNPsfw3whjZ304ynGRvzpau7EJcdb30tb30tb/03ZE1KFYtUafp1TnfrlNl6Mq0qgL t2Xl5zWhyFE6fl250IaCg+mdiGeR4gNOLBhTySmlXleU14kEllDEcpm1PpWcO6IsOilp8w9r T+RKuk6UwJKKTdz3B6VMOX9MeVzKkaQCSftOxWxMfDFqeZBR6jB+tHmLr15+NEt/p8HlDtt/ SjgkFQZZf9a32VW70j499dgg9CyW/xg+9kf+uYz9Ns62nNJgfBTXbmoVXPFtk4/G732h43I8 3rRPKkq2nk8t1uMDId+I0zxEfZcdY01N/vmf4ObCz3xSardbM3C+JVG93ZQxt+tj247LhILU qZRpSYRWp/wPOciOgZADAAA= X-CFilter-Loop: Reflected On Thu, Oct 02, 2025 at 12:39:31PM +0100, Mark Brown wrote: > On Thu, Oct 02, 2025 at 05:12:09PM +0900, Byungchul Park wrote: > > dept needs to notice every entrance from user to kernel mode to treat > > every kernel context independently when tracking wait-event dependencies. > > Roughly, system call and user oriented fault are the cases. > > > > Make dept aware of the entrances of arm64 and add support > > CONFIG_ARCH_HAS_DEPT_SUPPORT to arm64. > > The description of what needs to be tracked probably needs some > tightening up here, it's not clear to me for example why exceptions for > mops or the vector extensions aren't included here, or what the > distinction is with error faults like BTI or GCS not being tracked? Thanks for the feedback but I'm afraid I don't get you. Can you explain in more detail with example? JFYI, pairs of wait and its event need to be tracked to see if each event can be prevented from being reachable by other waits like: context X context Y lock L ... initiate event A context start toward event A ... ... wait A // wait for event A and lock L // wait for unlock L and // prevent unlock L // prevent event A ... ... unlock L unlock L ... event A I meant things like this need to be tracked. Byungchul