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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-c2dff70000001609-4b-699ba05fae7c Date: Mon, 23 Feb 2026 09:33:30 +0900 From: Byungchul Park To: Petr Pavlu Cc: 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, 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, 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, broonie@kernel.org, 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, 2407018371@qq.com, dakr@kernel.org, miguel.ojeda.sandonis@gmail.com, neilb@ownmail.net, bagasdotme@gmail.com, wsa+renesas@sang-engineering.com, dave.hansen@intel.com, geert@linux-m68k.org, ojeda@kernel.org, alex.gaynor@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v18 34/42] dept: add module support for struct dept_event_site and dept_event_site_dep Message-ID: <20260223003330.GB44876@system.software.com> References: <20251205071855.72743-1-byungchul@sk.com> <20251205071855.72743-35-byungchul@sk.com> <7afb6666-43b6-4d17-b875-e585c7a5ac99@suse.com> <20260213055006.GA55430@system.software.com> <7765df86-b08a-4f70-900d-4b4d85c07d49@suse.com> Precedence: bulk X-Mailing-List: rcu@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: <7765df86-b08a-4f70-900d-4b4d85c07d49@suse.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA02Sf1DTZRzH7/n+3s51TxPzUa5fS8/DzH4ccZ/ukOjqj++dd4aXd3napSu+ xa5t6KYgdRlzYINqER0S3xk3BZFgiQxR80IWg6UJBRa46bBEWBEsYm4zITC+dl3+87nXvZ/X vT+fPx6B1srccsFg3iVZzHqjjlMz6uiiw49td7sMTwT9y8BR+h4M2XwMJOIOBuZcp3hweGtY OHdpHwP9x5oRzFUGeKiyIbjdEUDgOWGjoOraKAdyxMXDpeQkglHf+wgOXRum4UTgKoKfElMc RAcOUjDQO4EgcrmDAntdCwcHPvcyUD2+AK1LwVVtpxbGbxT01oUZaCheCSONMg+33fkQaP6V h+GPqxg4Fv2BBc+HERq814dYqKkNc+CYiyModt1kod93gYULgXMMJJ2p0P/JRywEK8YQhKon eWicrmYh4L4P2jtLEcTqkwz0ub5nIez8nYH99a0UdLecoqAl4qfBn5ikYMQZ5cFlcyJwdCdp aO+5ycPx6aMc2G78jKAk/DT8dfw6C1/ODaHsbLGp7SQlemo9SJydqURi/IidFkvaCsWZxCAn diTdjPjdYSLWl81Q4lfyMC+6vbvFku4oK9Z9PU6Jh2IJVrw8sU70NpVxOQ9tUWfmSkZDgWR5 PGu7Oi/ibKV3hDL2nA7nFKPP0sqRSiA4nVwdvMKVI+EO9/oFJWbwStJ81okU5vAqEgzeohUl Ba8gF0eeK0dqgcYHHiDn2xys4izGRuL/dJpSHA0G4oktUWItTiDSF3pRYQ2+l5yvGWUUpvFq Epwfv6PTOJUcnRcUVOFMEu15UDGW4EeI7+S3lLKJ4IiKjNXE0L8HLyPfNAaZCoTlu1rlu1rl /1vdiG5CWoO5wKQ3GNPX5hWZDXvWvp5v8qKFH9vw7t9bT6NY/0tdCAtIt0jjm5INWlZfYC0y dSEi0LoUzezsQqTJ1Re9LVnyt1l2GyVrF0oVGN1SzVPJwlwtflO/S3pLknZIlv9eKUG1vBi9 sP9s+x8b3LOqLTilMuQo+3Fb9v23dk6/Zn1Uv/nPK1kZe+9ZXy6nb/xlcc8X6x8u3bgmfmbN cGfnjZ21vn3PdttfWRE3M4kjTWmN1oh5LGed/9WChl7TpirLhsGLhW8YZzIqhMwzaVl7nwm9 k7Xq5anR5x3z9XUTH1g39U3aTfRALDNDx1jz9E+upi1W/T8wE0YKrQMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA02SfUwbdRjHfe53vR6NZ86ubOeImnU2TsxejM48iXNxxrhzZnPinHFZ3Kq7 SEMpWzvZGDECtVrREKhpGe3QilIXqG5rGY4tVUIdAweRDiegvGym1hFgnUBZoJTaMzHunyff 53k+n+T542GJel6xkjWYDktmk96oZVS0asdT1rX7vB7Dhrn4/Wi3vYfDY1EF/lreTmNi1k7j iVN+BlOe75RoD9QpsGuggsa+b5sBxxJ2wNtJD0FbW5rGlKNTibPzvyvRWQ6YDnUCuiIOgoN9 PxD0t5RTOHN6icGJ8DSg83qUwdrxchrjvk8A3TGPEscvbsWpsQsKTI/8ReHA3CSgL7pEYbT9 Q8CUqwA/bwhmdNctBpO9PxOsdfYBfnF9hOD0+DXAls5RwNDJCgb/rD5LsD96D/6SiDPY7fyY wanICQpvnmbQWxFSYKRnArDe4wCM/Rai0PrlKQZd9QEa266dV2JkYpHCYZeDwubAdhzzxWi8 XN1AZc7NUGdWoKfWSmXKDQqd31ygcN7XpHymEcTbtipabAq2UqLtSooR/Z/5QUwuOECcbbQS 0VadacOTcSK+HzwiNl6eZMSFxFVGDM15afGnBkH86qMFSqzpXSu2uUeUO7fsUW06IBkNxZJ5 /eb9qvxY1RlycOjJo+eGd5bB8UcqgWUF/gmhJ8xWQhZL8zqh+fsqkDPDPywMDs4TGdHwDwlX /thSCSqW8K4HhO6gXSEzy3ijEP70b0pmOB4F/3S2PFbzCRB6h16SM8ffK3TXRWk5Ez5XGFwa /xcnfI7w9RIrxyx+kzB18UGZyOZXC+2tl6hq4Nx3yO47ZPf/shdIE2gMpuJCvcG4cZ2lIL/E ZDi67q2iwgBkHtL37mLNOZjt39oBPAvau7lb93kMaoW+2FJS2AECS7QaLpl0G9TcAX3JMclc tM/8jlGydEAOS2tXcNtek/ar+bf1h6UCSToomf/bUmzWyjJ481i6LLZo1nj7D63GILf8lR6z LlTwslN/12R6d9zZ0jXQym6eXnboyO6hIrixUTHzqu+F0tIPXr/KWbcnt+19uk633vNjIO/x Ndl5nGn5s6N7F3TdeaZHzz9X6grtmtmVU3Pp+eNrVrV0rdqjC2t6TcWjG07mvng2MpBqrLe9 kU7f1NKWfP1jucRs0f8DOc5IfIwDAAA= X-CFilter-Loop: Reflected On Wed, Feb 18, 2026 at 04:08:19PM +0100, Petr Pavlu wrote: > On 2/13/26 6:50 AM, Byungchul Park wrote: > > On Wed, Jan 07, 2026 at 01:19:00PM +0100, Petr Pavlu wrote: > >> On 12/5/25 8:18 AM, Byungchul Park wrote: > >>> struct dept_event_site and struct dept_event_site_dep have been > >>> introduced to track dependencies between multi event sites for a single > >>> wait, that will be loaded to data segment. Plus, a custom section, > >>> '.dept.event_sites', also has been introduced to keep pointers to the > >>> objects to make sure all the event sites defined exist in code. > >>> > >>> dept should work with the section and segment of module. Add the > >>> support to handle the section and segment properly whenever modules are > >>> loaded and unloaded. > >>> > >>> Signed-off-by: Byungchul Park > >> > >> Below are a few comments from the module loader perspective. > > > > Sorry about the late reply. I've been going through some major life > > changes lately. :( > > > > Thank you sooooo~ much for your helpful feedback. I will leave my > > opinion below. > > > [...] > >>> diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c > >>> index b14400c4f83b..07d883579269 100644 > >>> --- a/kernel/dependency/dept.c > >>> +++ b/kernel/dependency/dept.c > >>> @@ -984,6 +984,9 @@ static void bfs(void *root, struct bfs_ops *ops, void *in, void **out) > >>> * event sites. > >>> */ > >>> > >>> +static LIST_HEAD(dept_event_sites); > >>> +static LIST_HEAD(dept_event_site_deps); > >>> + > >>> /* > >>> * Print all events in the circle. > >>> */ > >>> @@ -2043,6 +2046,33 @@ static void del_dep_rcu(struct rcu_head *rh) > >>> preempt_enable(); > >>> } > >>> > >>> +/* > >>> + * NOTE: Must be called with dept_lock held. > >>> + */ > >>> +static void disconnect_event_site_dep(struct dept_event_site_dep *esd) > >>> +{ > >>> + list_del_rcu(&esd->dep_node); > >>> + list_del_rcu(&esd->dep_rev_node); > >>> +} > >>> + > >>> +/* > >>> + * NOTE: Must be called with dept_lock held. > >>> + */ > >>> +static void disconnect_event_site(struct dept_event_site *es) > >>> +{ > >>> + struct dept_event_site_dep *esd, *next_esd; > >>> + > >>> + list_for_each_entry_safe(esd, next_esd, &es->dep_head, dep_node) { > >>> + list_del_rcu(&esd->dep_node); > >>> + list_del_rcu(&esd->dep_rev_node); > >>> + } > >>> + > >>> + list_for_each_entry_safe(esd, next_esd, &es->dep_rev_head, dep_rev_node) { > >>> + list_del_rcu(&esd->dep_node); > >>> + list_del_rcu(&esd->dep_rev_node); > >>> + } > >>> +} > >>> + > >>> /* > >>> * NOTE: Must be called with dept_lock held. > >>> */ > >>> @@ -2384,6 +2414,8 @@ void dept_free_range(void *start, unsigned int sz) > >>> { > >>> struct dept_task *dt = dept_task(); > >>> struct dept_class *c, *n; > >>> + struct dept_event_site_dep *esd, *next_esd; > >>> + struct dept_event_site *es, *next_es; > >>> unsigned long flags; > >>> > >>> if (unlikely(!dept_working())) > >>> @@ -2405,6 +2437,24 @@ void dept_free_range(void *start, unsigned int sz) > >>> while (unlikely(!dept_lock())) > >>> cpu_relax(); > >>> > >>> + list_for_each_entry_safe(esd, next_esd, &dept_event_site_deps, all_node) { > >>> + if (!within((void *)esd, start, sz)) > >>> + continue; > >>> + > >>> + disconnect_event_site_dep(esd); > >>> + list_del(&esd->all_node); > >>> + } > >>> + > >>> + list_for_each_entry_safe(es, next_es, &dept_event_sites, all_node) { > >>> + if (!within((void *)es, start, sz) && > >>> + !within(es->name, start, sz) && > >>> + !within(es->func_name, start, sz)) > >>> + continue; > >>> + > >>> + disconnect_event_site(es); > >>> + list_del(&es->all_node); > >>> + } > >>> + > >>> list_for_each_entry_safe(c, n, &dept_classes, all_node) { > >>> if (!within((void *)c->key, start, sz) && > >>> !within(c->name, start, sz)) > >>> @@ -3337,6 +3387,7 @@ void __dept_recover_event(struct dept_event_site_dep *esd, > >>> > >>> list_add(&esd->dep_node, &es->dep_head); > >>> list_add(&esd->dep_rev_node, &rs->dep_rev_head); > >>> + list_add(&esd->all_node, &dept_event_site_deps); > >>> check_recover_dl_bfs(esd); > >>> unlock: > >>> dept_unlock(); > >>> @@ -3347,6 +3398,23 @@ EXPORT_SYMBOL_GPL(__dept_recover_event); > >>> > >>> #define B2KB(B) ((B) / 1024) > >>> > >>> +void dept_mark_event_site_used(void *start, void *end) > >> > >> Nit: I suggest that dept_mark_event_site_used() take pointers to > >> dept_event_site_init, which would catch the type mismatch with > > > > IMO, this is the easiest way to get all the pointers from start to the > > end, or I can't get the number of the pointers. It's similar to the > > initcalls section for device drivers. > > This was a minor suggestion.. The idea is to simply change the function > signature to: > > void dept_mark_event_site_used(struct dept_event_site_init **start, > struct dept_event_site_init **end)) I got what you meant. I will. Thanks. Byungchul > This way, the compiler can provide proper type checking to ensure that > correct pointers are passed to dept_mark_event_site_used(). It would > catch the type mismatch with module::dept_event_sites. > > > > >> module::dept_event_sites. > >> > >>> +{ > >>> + struct dept_event_site_init **evtinitpp; > >>> + > >>> + for (evtinitpp = (struct dept_event_site_init **)start; > >>> + evtinitpp < (struct dept_event_site_init **)end; > >>> + evtinitpp++) { > >>> + (*evtinitpp)->evt_site->used = true; > >>> + (*evtinitpp)->evt_site->func_name = (*evtinitpp)->func_name; > >>> + list_add(&(*evtinitpp)->evt_site->all_node, &dept_event_sites); > >>> + > >>> + pr_info("dept_event_site %s@%s is initialized.\n", > >>> + (*evtinitpp)->evt_site->name, > >>> + (*evtinitpp)->evt_site->func_name); > >>> + } > >>> +} > >>> + > >>> extern char __dept_event_sites_start[], __dept_event_sites_end[]; > >> > >> Related to the above, __dept_event_sites_start and > >> __dept_event_sites_end can already be properly typed here. > > > > How can I get the number of the pointers? > > Similarly here, changing the code to: > > extern struct dept_event_site_init *__dept_event_sites_start[], *__dept_event_sites_end[]; > > It is the same for the initcalls you mentioned. The declarations of > their start/end symbols are also already properly typed as > initcall_entry_t[] in include/linux/init.h. > > -- > Thanks, > Petr