From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5E7923770B; Fri, 3 Oct 2025 01:46:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.125.252.92 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759456013; cv=none; b=O3b7FxoCka5EHoqpWtJS4gCxNU8HneSSaZ96M5bqso40y0SCcrCTDvwXPOnhCkXVOlQSUSpL3QYvqwBtrTjlfWVNE87qMkJ6Ay8helyrRyymJauT5Tvszh/mmq6JoO0Z7ABu7tCEObe8Bm3Sd8hqpBSgWA01o9whDnabcKBUy00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759456013; c=relaxed/simple; bh=qSeKLacpwTszi2nIGhZR51FDuj9AbbAKRr2JI/VVMs8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RiLUbylOq6rqiVEx/3zKDidJwUsOlKZ4KjLJE+eUxmIqlsDJW3IEMRXQFJvGpbSShOBdDVjTE1/ajOldpYZEDHu0DoKERAattu+PRrhLSImijSXiBoguZqnMzH5JCpVk+zrGiF2SW/3FWLnYechxH6qTBXnknh3qfID/F8FICLY= ARC-Authentication-Results:i=1; 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-c45ff70000001609-82-68df2b066d8f 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-block@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: H4sIAAAAAAAAA02Sa0yTZxTH87zPe6PhTR4rzEf5Vk2MGLwnnhiybMuMT0SNFz4YjdEqb2wD 5VKQCcmy4rxCZbiJl1ZMQa2VgppiDGbgEDZMizpmlDSzVBAF2aRMhSIiKC/GzG+/nPM/v3M+ HBnr7wmzZHNmnmrNNGYYRB2vG4itSpLmPzYt6joqwciYE0PNtSIOTvYX8TDotiNw9DolGD+R DpXdnRieXz2E4FprGIG/vESEyFURXPsaBahw/ozgRIWPB69v7eS0CM6TP3Jw51yIh1ZvnwRD D7o5qLH3YvD1dAjQ+Pd8aK1/woHNOSJAd1dQgGhpAgTLniGojVSJ8G/UjeF+k4uDVtcX8Op8 lIfbR5s4uDAUwXDXeU+AUOk/PFzwDAjQ56jgoGX4BQeBztcS/HLfJULgbYCDA/ZRCZxFpQgO /x7FMPbmjAi14x3oq0Ws5mwNYi0vBjF7O/xQZI1RF88CVZQdu5vEbjg6Jeby7WF1nkR2rqGf Y77qIyILdTSIrNJWjtlZ/wZWd/4H9miiB6+nW3TJaWqGOV+1Lvxyh870174xKfuObm97+SBn QxGpGMkyJcto2/vNxShmCkOe56LGPJlD6561TbFI5tJgcBRrHEdm04cjjXwx0smYVCbQiwNX BK0xnWyn7y494DSnQoAO1Zu1jJ6cRvTm8WZeyyhkGvWffjrFmCTS4ET/VB6TSc+ErJVjyNc0 XBLiNI6f3NV0/TaneSgJx9DBm7/xHw+dSW95gnwZIo7PtI7PtI7/tS6Eq5HenJlvMZozli0w FWSa9y7YlWXxockvc3//bms9etW+qRkRGRliFZYdNukFY35ugaUZURkb4pQdnpBJr6QZCwpV a9Z2654MNbcZJci8YYayJPpdmp7sNuap6aqarVo/dTk5ZpYNbRvNWzl793+/upOvuP+MpH5b 8NPFw08blNQZyTnrnEqkvv0bL79mBVoT4P32CWUUW4S5S1Pb08KH/khZbd/S5/DcsG2c15Kz /EDs5bKUU4m6XfuHV/S+ZMv9O697K3pWLrFsLnTZDz5ylJRHU0iOd2BOfNLM8ZTjY7R6uiys 2thn4HNNxsWJ2Jpr/ADqIHiCYQMAAA== 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