Linaro-mm-sig May 2026

linaro-mm-sig@lists.linaro.org

107 participants
346 discussions

[PATCH v3 00/10] Add dmabuf read/write via io_uring

by Pavel Begunkov

The patch set allows to register a dmabuf to an io_uring instance for a specified file and use it with io_uring read / write requests. The infrastructure is not tied to io_uring and there could be more users in the future. A similar idea was attempted some years ago by Keith [1], from where I borrowed a good number of changes, and later was brough up by Tushar and Vishal from Intel. It's an opt-in feature for files, and they need to implement a new file operation to use it. Only NVMe block devices are supported in this series. The user API is built on top of io_uring's "registered buffers", where a dmabuf is registered in a special way, but after it can be used as any other "registered buffer" with IORING_OP_{READ,WRITE}_FIXED requests. It's created via a new file operation and the resulted map is then passed through the I/O stack in a new iterator type. There is some additional infrastructure to bind it all, which also counts requests using a dmabuf map and managing lifetimes, which is used to implement map invalidation. It was tested for GPU <-> NVMe transfers. Also, as it maintains a long-term dma mapping, it helps with the IOMMU cost. The numbers below are for udmabuf reads previously run by Anuj for different IOMMU modes: - STRICT: before = 570 KIOPS, after = 5.01 MIOPS - LAZY: before = 1.93 MIOPS, after = 5.01 MIOPS - PASSTHROUGH: before = 5.01 MIOPS, after = 5.01 MIOPS There are some liburing tests that can serve as an example: git: https://github.com/isilence/liburing.git rw-dmabuf-tests-v3 url: https://github.com/isilence/liburing/tree/rw-dmabuf-tests-v3 [1] https://lore.kernel.org/io-uring/20220805162444.3985535-1-kbusch@fb.com/ v3: - Rework io_uring registration - Move token/map infrastructure code out of blk-mq - Simplify callbacks: remove a separate blk-mq table, which was mostly just forwarding calls (to nvme). - Don't skip dma sync depending on request direction - Fix a couple of hangs - Rename s/dma/dmabuf/ - Other small changes v2: - Don't pass raw dma addresses, wrap it into a driver specific object - Split into two objects: token and map - Implement move_notify Pavel Begunkov (10): file: add callback for creating long-term dmabuf maps iov_iter: add iterator type for dmabuf maps block: move bvec init into __bio_clone block: introduce dma map backed bio type lib: add dmabuf token infrastructure block: forward create_dmabuf_token to drivers nvme-pci: implement dma_token backed requests io_uring/rsrc: introduce buf registration structure io_uring/rsrc: extend buffer update io_uring/rsrc: add dmabuf backed registered buffers block/bio.c | 28 +++- block/blk-merge.c | 14 ++ block/blk.h | 3 +- block/fops.c | 16 ++ drivers/nvme/host/pci.c | 282 ++++++++++++++++++++++++++++++++ include/linux/bio.h | 19 ++- include/linux/blk-mq.h | 9 + include/linux/blk_types.h | 8 +- include/linux/fs.h | 2 + include/linux/io_dmabuf_token.h | 92 +++++++++++ include/linux/io_uring_types.h | 5 + include/linux/uio.h | 11 ++ include/uapi/linux/io_uring.h | 31 +++- io_uring/io_uring.c | 3 +- io_uring/rsrc.c | 266 +++++++++++++++++++++++++----- io_uring/rsrc.h | 30 +++- io_uring/rw.c | 4 +- lib/Kconfig | 4 + lib/Makefile | 2 + lib/io_dmabuf_token.c | 272 ++++++++++++++++++++++++++++++ lib/iov_iter.c | 29 +++- 21 files changed, 1071 insertions(+), 59 deletions(-) create mode 100644 include/linux/io_dmabuf_token.h create mode 100644 lib/io_dmabuf_token.c -- 2.53.0

1 day, 2 hours

A Guide to Mastering Slope

by sarahcolter＠wshu.net

Have you ever felt the exhilarating rush of speed, the focus demanded by precision, and the utter satisfaction of overcoming a seemingly impossible challenge? If so, then you might just be ready to tackle Slope. This deceptively simple online game has captivated players with its addictive gameplay and endless potential for improvement. It's a perfect little escape for a quick break or a dedicated practice session. Let's dive into how to play and, more importantly, how to experience the thrill of Slope. Introduction: What is Slope? At its core, Slope is a rolling ball game. You control a ball that’s constantly moving downhill, navigating a procedurally generated landscape of interconnected platforms. Sounds straightforward, right? Don’t be fooled! The platforms narrow, the speed increases relentlessly, and the gaps between platforms widen as you progress. One wrong move and you’re plummeting into the abyss. https://slopegame-online.com The brilliance of Slope lies in its accessibility and its learning curve. It's incredibly easy to pick up and play, yet fiendishly difficult to master. You don't need complicated controllers or extensive tutorials. Just a keyboard, a steady hand, and a determined spirit. It's a perfect example of a simple concept executed brilliantly. Gameplay: Navigating the Perilous Path The controls are as minimal as the aesthetic: the left and right arrow keys are all you need to guide your ball. Use the left arrow key to steer the ball left, and the right arrow key to steer it right. That's it! But mastering those two keys is the key to survival. Your objective is to stay on the platforms for as long as possible. As you roll further down the slope, your speed increases, and the environment becomes increasingly challenging. Red blocks appear, acting as obstacles that instantly end your run if touched. The platforms themselves will start to shift and move, adding another layer of complexity to the game. The game ends when your ball falls off the platform. Your score is determined by the distance you travelled before your demise. The higher the score, the better! The goal is to constantly improve your score, pushing yourself to see just how far you can go. Tips and Tricks for Conquering the Slope While the controls are simple, mastering Slope requires practice and a good understanding of the game's mechanics. Here are a few tips to help you improve your game: Smooth Movements Are Key: Avoid jerky, panicked movements. Small, controlled adjustments are far more effective than large, sweeping ones. Think less about reacting and more about anticipating. Look Ahead: Try to focus a little further down the slope. Anticipating the next turn or gap will give you more time to react and adjust your trajectory. This is easier said than done when the speed is high, but it's a crucial skill to develop. Embrace the Momentum: Understand how your ball's momentum affects its movement. Learn how to use the slight curve of the platforms to your advantage, especially when approaching tight turns. Don't Fear the Edges: Sometimes, the safest route is to ride along the edge of the platform. This allows you to make small corrections and avoid potential obstacles in the center. Practice, Practice, Practice: There's no substitute for practice. The more you play, the better you'll become at anticipating the challenges and reacting accordingly. Don't get discouraged by early failures. Everyone starts somewhere. You can visit Slope to begin practicing! Learn from Your Mistakes: Analyze your failures. What caused you to fall off the platform? Were you too slow to react? Did you misjudge the turn? Understanding your mistakes will help you avoid them in the future. Conclusion: The Enduring Appeal of an Endless Game Slope isn't about complicated storylines, stunning graphics, or intricate controls. It's about the pure, unadulterated challenge of pushing your skills to the limit. It's about the satisfaction of mastering a seemingly impossible task. It's about the addictive loop of playing, failing, learning, and improving. And its accessible nature means anyone can jump in and experience that thrill. So, go ahead, give it a try. You might just find yourself hooked on the endless decline. The simple controls and challenging gameplay make it a strangely addictive experience. It's a testament to the idea that sometimes, the simplest games are the most engaging.

5 days, 7 hours

What's Wave Rider game?

by Leo Enda

Wave Rider surprised me more than I expected. The game looks simple at first, but once the speed increases and the waves become unstable, every run starts feeling intense. Unlike many endless runner games that rely only on fast movement, Wave Rider creates pressure through unpredictable water physics and constantly changing obstacle patterns. Play Wave Rider online at https://wave-rider.io The gameplay is built around survival. Your board moves forward automatically while you focus on steering through dangerous sections of water. Floating barriers, underwater mines, sharp turns, and narrow lanes appear quickly, forcing players to react within seconds. What I liked most is how the game balances smooth surfing movement with sudden moments of chaos. Sometimes the water feels calm, then everything changes when multiple obstacles appear together. Wave Rider also rewards risky decisions. Pearls are often hidden near dangerous routes, making players choose between safe movement and higher scores. I found myself taking bigger risks after every run just to see how far I could push the distance counter. The durability system adds even more tension because repeated small crashes slowly reduce your chance of surviving longer sessions. Game Controls Left Arrow / A: Move left Right Arrow / D: Move right Spacebar or Up Arrow: Jump or glide over obstacles The controls are easy to learn, but mastering the timing takes practice. Quick reactions help, but smooth movement and patience usually lead to better runs. Players who panic and change direction too aggressively often crash faster than expected. Overall, Wave Rider feels like a solid arcade experience for anyone who enjoys reaction-based gameplay. The combination of flowing water, rising speed, and nonstop danger makes every session feel fresh and competitive.

1 week, 1 day

[PATCH v18 00/42] DEPT(DEPendency Tracker)

by Byungchul Park

I'm happy to see that DEPT reported real problems in practice: https://lore.kernel.org/lkml/6383cde5-cf4b-facf-6e07-1378a485657d@I-love.SA… https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.pa… https://lore.kernel.org/all/b6e00e77-4a8c-4e05-ab79-266bf05fcc2d@igalia.com/ I’ve added documentation describing DEPT — this should help you understand what DEPT is and how it works. You can use DEPT simply by enabling CONFIG_DEPT and checking dmesg at runtime. --- Hi Linus and folks, I’ve been developing a tool to detect deadlock possibilities by tracking waits/events — rather than lock acquisition order — to cover all the synchronization mechanisms. To summarize the design rationale, starting from the problem statement, through analysis, to the solution: CURRENT STATUS -------------- Lockdep tracks lock acquisition order to identify deadlock conditions. Additionally, it tracks IRQ state changes — via {en,dis}able — to detect cases where locks are acquired unintentionally during interrupt handling. PROBLEM ------- Waits and their associated events that are never reachable can eventually lead to deadlocks. However, since Lockdep focuses solely on lock acquisition order, it has inherent limitations when handling waits and events. Moreover, by tracking only lock acquisition order, Lockdep cannot properly handle read locks or cross-event scenarios — such as wait_for_completion() and complete() — making it increasingly inadequate as a general-purpose deadlock detection tool. SOLUTION -------- Once again, waits and their associated events that are never reachable can eventually lead to deadlocks. The new solution, DEPT, focuses directly on waits and events. DEPT monitors waits and events, and reports them when any become unreachable. DEPT provides: * Correct handling of read locks. * Support for general waits and events. * Continuous operation, even after multiple reports. * Simple, intuitive annotation APIs. There are still false positives, and some are already being worked on for suppression. Especially splitting the folio class into several appropriate classes e.g. block device mapping class and regular file mapping class, is currently under active development by me and Yeoreum Yun. Anyway, these efforts will need to continue for a while, as we’ve seen with lockdep over two decades. DEPT is tagged as EXPERIMENTAL in Kconfig — meaning it’s not yet suitable for use as an automation tool. However, for those who are interested in using DEPT to analyze complex synchronization patterns and extract dependency insights, DEPT would be a great tool for the purpose. Thanks for your support and contributions to: Harry Yoo <harry.yoo(a)oracle.com> Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Yunseong Kim <ysk(a)kzalloc.com> Yeoreum Yun <yeoreum.yun(a)arm.com> FAQ --- Q. Is this the first attempt to solve this problem? A. No. The cross-release feature (commit b09be676e0ff2) attempted to address it — as a Lockdep extension. It was merged, but quickly reverted, because: While it uncovered valuable hidden issues, it also introduced false positives. Since these false positives mask further real problems with Lockdep — and developers strongly dislike them — the feature was rolled back. Q. Why wasn’t DEPT built as a Lockdep extension? A. Lockdep is the result of years of work by kernel developers — and is now very stable. But I chose to build DEPT separately, because: While reusing BFS(Breadth First Search) and Lockdep’s hashing is beneficial, the rest of the system must be rebuilt from scratch to align with DEPT’s wait-event model — since Lockdep was originally designed for tracking lock acquisition orders, not wait-event dependencies. Q. Do you plan to replace Lockdep entirely? A. Not at all — Lockdep still plays a vital role in validating correct lock usage. While its dependency-checking logic should eventually be superseded by DEPT, the rest of its functionality should stay. Q. Should we replace the dependency check immediately? A. Absolutely not. Lockdep’s stability is the result of years of hard work by kernel developers. Lockdep and DEPT should run side by side until DEPT matures. Q. Stronger detection often leads to more false positives — which was a major pain point when cross-release was added. Is DEPT designed to handle this? A. Yes. DEPT’s simple, generalized design enables flexible reporting — so while false positives still need fixing, they’re far less disruptive than they were under the Lockdep extension, cross-release. Q. Why not fix all false positives out-of-tree before merging? A. Since the affected subsystems span the entire kernel, like Lockdep, which has relied on annotations to avoid false positives over the last two decades, DEPT too will require the annotation efforts. Performing annotation work within the mainline will help us add annotations more appropriately and will also make DEPT a useful tool for a wider range of users more quickly. CONFIG_DEPT is marked EXPERIMENTAL, so it’s opt-in. Some users are already interested in using DEPT to analyze complex synchronization patterns and extract dependency insights. Byungchul --- Changes from v17: 1. Rebase on the mainline as of 2025 Dec 5. 2. Convert the documents' format from txt to rst. (feedbacked by Jonathan Corbet and Bagas Sanjaya) 3. Move the documents from 'Documentation/dependency' to 'Documentation/dev-tools'. (feedbakced by Jonathan Corbet) 4. Improve the documentation. (feedbacked by NeilBrown) 5. Use a common function, enter_from_user_mode(), instead of arch specific code, to notice context switch from user mode. (feedbacked by Dave Hansen, Mark Rutland, and Mark Brown) 6. Resolve the header dependency issue by using dept's internal header, instead of relocating 'struct llist_{head,node}' to another header. (feedbacked by Greg KH) 7. Improve page(or folio) usage type APIs. 8. Add rust helper for wait_for_completion(). (feedbacked by Guangbo Cui, Boqun Feng, and Danilo Krummrich) 9. Refine some commit messages. Changes from v16: 1. Rebase on v6.17. 2. Fix a false positive from rcu (by Yunseong Kim) 3. Introduce APIs to set page's usage, dept_set_page_usage() and dept_reset_page_usage() to avoid false positives. 4. Consider lock_page() as a potential wait unconditionally. 5. Consider folio_lock_killable() as a potential wait unconditionally. 6. Add support for tracking PG_writeback waits and events. 7. Fix two build errors due to the additional debug information added by dept. (by Yunseong Kim) Changes from v15: 1. Fix typo and improve comments and commit messages (feedbacked by ALOK TIWARI, Waiman Long, and kernel test robot). 2. Do not stop dept on detection of cicular dependency of recover event, allowing to keep reporting. 3. Add SK hynix to copyright. 4. Consider folio_lock() as a potential wait unconditionally. 5. Fix Kconfig dependency bug (feedbacked by kernel test rebot). 6. Do not suppress reports that involve classes even that have already involved in other reports, allowing to keep reporting. Changes from v14: 1. Rebase on the current latest, v6.15-rc6. 2. Refactor dept code. 3. With multi event sites for a single wait, even if an event forms a circular dependency, the event can be recovered by other event(or wake up) paths. Even though informing the circular dependency is worthy but it should be suppressed once informing it, if it doesn't lead an actual deadlock. So introduce APIs to annotate the relationship between event site and recover site, that are, event_site() and dept_recover_event(). 4. wait_for_completion() worked with dept map embedded in struct completion. However, it generates a few false positves since all the waits using the instance of struct completion, share the map and key. To avoid the false positves, make it not to share the map and key but each wait_for_completion() caller have its own key by default. Of course, external maps also can be used if needed. 5. Fix a bug about hardirq on/off tracing. 6. Implement basic unit test for dept. 7. Add more supports for dma fence synchronization. 8. Add emergency stop of dept e.g. on panic(). 9. Fix false positives by mmu_notifier_invalidate_*(). 10. Fix recursive call bug by DEPT_WARN_*() and DEPT_STOP(). 11. Fix trivial bugs in DEPT_WARN_*() and DEPT_STOP(). 12. Fix a bug that a spin lock, dept_pool_spin, is used in both contexts of irq disabled and enabled without irq disabled. 13. Suppress reports with classes, any of that already have been reported, even though they have different chains but being barely meaningful. 14. Print stacktrace of the wait that an event is now waking up, not only stacktrace of the event. 15. Make dept aware of lockdep_cmp_fn() that is used to avoid false positives in lockdep so that dept can also avoid them. 16. Do do_event() only if there are no ecxts have been delimited. 17. Fix a bug that was not synchronized for stage_m in struct dept_task, using a spin lock, dept_task()->stage_lock. 18. Fix a bug that dept didn't handle the case that multiple ttwus for a single waiter can be called at the same time e.i. a race issue. 19. Distinguish each kernel context from others, not only by system call but also by user oriented fault so that dept can work with more accuracy information about kernel context. That helps to avoid a few false positives. 20. Limit dept's working to x86_64 and arm64. Changes from v13: 1. Rebase on the current latest version, v6.9-rc7. 2. Add 'dept' documentation describing dept APIs. Changes from v12: 1. Refine the whole document for dept. 2. Add 'Interpret dept report' section in the document, using a deadlock report obtained in practice. Hope this version of document helps guys understand dept better. https://lore.kernel.org/lkml/6383cde5-cf4b-facf-6e07-1378a485657d@I-love.SA… https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.pa… Changes from v11: 1. Add 'dept' documentation describing the concept of dept. 2. Rewrite the commit messages of the following commits for using weaker lockdep annotation, for better description. fs/jbd2: Use a weaker annotation in journal handling cpu/hotplug: Use a weaker annotation in AP thread (feedbacked by Thomas Gleixner) Changes from v10: 1. Fix noinstr warning when building kernel source. 2. dept has been reporting some false positives due to the folio lock's unfairness. Reflect it and make dept work based on dept annotaions instead of just wait and wake up primitives. 3. Remove the support for PG_writeback while working on 2. I will add the support later if needed. 4. dept didn't print stacktrace for [S] if the participant of a deadlock is not lock mechanism but general wait and event. However, it made hard to interpret the report in that case. So add support to print stacktrace of the requestor who asked the event context to run - usually a waiter of the event does it just before going to wait state. 5. Give up tracking raw_local_irq_{disable,enable}() since it totally messed up dept's irq tracking. So make it work in the same way as lockdep does. I will consider it once any false positives by those are observed again. 6. Change the manual rwsem_acquire_read(->j_trans_commit_map) annotation in fs/jbd2/transaction.c to the try version so that it works as much as it exactly needs. 7. Remove unnecessary 'inline' keyword in dept.c and add '__maybe_unused' to a needed place. Changes from v9: 1. Fix a bug. SDT tracking didn't work well because of my big mistake that I should've used waiter's map to indentify its class but it had been working with waker's one. FYI, PG_locked and PG_writeback weren't affected. They still worked well. (reported by YoungJun) Changes from v8: 1. Fix build error by adding EXPORT_SYMBOL(PG_locked_map) and EXPORT_SYMBOL(PG_writeback_map) for kernel module build - appologize for that. (reported by kernel test robot) 2. Fix build error by removing header file's circular dependency that was caused by "atomic.h", "kernel.h" and "irqflags.h", which I introduced - appolgize for that. (reported by kernel test robot) Changes from v7: 1. Fix a bug that cannot track rwlock dependency properly, introduced in v7. (reported by Boqun and lockdep selftest) 2. Track wait/event of PG_{locked,writeback} more aggressively assuming that when a bit of PG_{locked,writeback} is cleared there might be waits on the bit. (reported by Linus, Hillf and syzbot) 3. Fix and clean bad style code e.i. unnecessarily introduced a randome pattern and so on. (pointed out by Linux) 4. Clean code for applying dept to wait_for_completion(). Changes from v6: 1. Tie to task scheduler code to track sleep and try_to_wake_up() assuming sleeps cause waits, try_to_wake_up()s would be the events that those are waiting for, of course with proper dept annotations, sdt_might_sleep_weak(), sdt_might_sleep_strong() and so on. For these cases, class is classified at sleep entrance rather than the synchronization initialization code. Which would extremely reduce false alarms. 2. Remove the dept associated instance in each page struct for tracking dependencies by PG_locked and PG_writeback thanks to the 1. work above. 3. Introduce CONFIG_dept_AGGRESIVE_TIMEOUT_WAIT to suppress reports that waits with timeout set are involved, for those who don't like verbose reporting. 4. Add a mechanism to refill the internal memory pools on running out so that dept could keep working as long as free memory is available in the system. 5. Re-enable tracking hashed-waitqueue wait. That's going to no longer generate false positives because class is classified at sleep entrance rather than the waitqueue initailization. 6. Refactor to make it easier to port onto each new version of the kernel. 7. Apply dept to dma fence. 8. Do trivial optimizaitions. Changes from v5: 1. Use just pr_warn_once() rather than WARN_ONCE() on the lack of internal resources because WARN_*() printing stacktrace is too much for informing the lack. (feedback from Ted, Hyeonggon) 2. Fix trivial bugs like missing initializing a struct before using it. 3. Assign a different class per task when handling onstack variables for waitqueue or the like. Which makes dept distinguish between onstack variables of different tasks so as to prevent false positives. (reported by Hyeonggon) 4. Make dept aware of even raw_local_irq_*() to prevent false positives. (reported by Hyeonggon) 5. Don't consider dependencies between the events that might be triggered within __schedule() and the waits that requires __schedule(), real ones. (reported by Hyeonggon) 6. Unstage the staged wait that has prepare_to_wait_event()'ed *and* yet to get to __schedule(), if we encounter __schedule() in-between for another sleep, which is possible if e.g. a mutex_lock() exists in 'condition' of ___wait_event(). 7. Turn on CONFIG_PROVE_LOCKING when CONFIG_DEPT is on, to rely on the hardirq and softirq entrance tracing to make dept more portable for now. Changes from v4: 1. Fix some bugs that produce false alarms. 2. Distinguish each syscall context from another *for arm64*. 3. Make it not warn it but just print it in case dept ring buffer gets exhausted. (feedback from Hyeonggon) 4. Explicitely describe "EXPERIMENTAL" and "dept might produce false positive reports" in Kconfig. (feedback from Ted) Changes from v3: 1. dept shouldn't create dependencies between different depths of a class that were indicated by *_lock_nested(). dept normally doesn't but it does once another lock class comes in. So fixed it. (feedback from Hyeonggon) 2. dept considered a wait as a real wait once getting to __schedule() even if it has been set to TASK_RUNNING by wake up sources in advance. Fixed it so that dept doesn't consider the case as a real wait. (feedback from Jan Kara) 3. Stop tracking dependencies with a map once the event associated with the map has been handled. dept will start to work with the map again, on the next sleep. Changes from v2: 1. Disable dept on bit_wait_table[] in sched/wait_bit.c reporting a lot of false positives, which is my fault. Wait/event for bit_wait_table[] should've been tagged in a higher layer for better work, which is a future work. (feedback from Jan Kara) 2. Disable dept on crypto_larval's completion to prevent a false positive. Changes from v1: 1. Fix coding style and typo. (feedback from Steven) 2. Distinguish each work context from another in workqueue. 3. Skip checking lock acquisition with nest_lock, which is about correct lock usage that should be checked by lockdep. Changes from RFC(v0): 1. Prevent adding a wait tag at prepare_to_wait() but __schedule(). (feedback from Linus and Matthew) 2. Use try version at lockdep_acquire_cpus_lock() annotation. 3. Distinguish each syscall context from another. Byungchul Park (41): dept: implement DEPT(DEPendency Tracker) dept: add single event dependency tracker APIs dept: add lock dependency tracker APIs dept: tie to lockdep and IRQ tracing dept: add proc knobs to show stats and dependency graph dept: distinguish each kernel context from another dept: distinguish each work from another dept: add a mechanism to refill the internal memory pools on running out dept: record the latest one out of consecutive waits of the same class dept: apply sdt_might_sleep_{start,end}() to wait_for_completion()/complete() dept: apply sdt_might_sleep_{start,end}() to swait dept: apply sdt_might_sleep_{start,end}() to waitqueue wait dept: apply sdt_might_sleep_{start,end}() to hashed-waitqueue wait dept: apply sdt_might_sleep_{start,end}() to dma fence dept: track timeout waits separately with a new Kconfig dept: apply timeout consideration to wait_for_completion()/complete() dept: apply timeout consideration to swait dept: apply timeout consideration to waitqueue wait dept: apply timeout consideration to hashed-waitqueue wait dept: apply timeout consideration to dma fence wait dept: make dept able to work with an external wgen dept: track PG_locked with dept dept: print staged wait's stacktrace on report locking/lockdep: prevent various lockdep assertions when lockdep_off()'ed dept: add documents for dept cpu/hotplug: use a weaker annotation in AP thread dept: assign dept map to mmu notifier invalidation synchronization dept: assign unique dept_key to each distinct dma fence caller dept: make dept aware of lockdep_set_lock_cmp_fn() annotation dept: make dept stop from working on debug_locks_off() dept: assign unique dept_key to each distinct wait_for_completion() caller completion, dept: introduce init_completion_dmap() API dept: introduce a new type of dependency tracking between multi event sites dept: add module support for struct dept_event_site and dept_event_site_dep dept: introduce event_site() to disable event tracking if it's recoverable dept: implement a basic unit test for dept dept: call dept_hardirqs_off() in local_irq_*() regardless of irq state dept: introduce APIs to set page usage and use subclasses_evt for the usage dept: track PG_writeback with dept SUNRPC: relocate struct rcu_head to the first field of struct rpc_xprt mm: percpu: increase PERCPU_DYNAMIC_SIZE_SHIFT on DEPT and large PAGE_SIZE Yunseong Kim (1): rcu/update: fix same dept key collision between various types of RCU Documentation/dev-tools/dept.rst | 778 ++++++ Documentation/dev-tools/dept_api.rst | 125 + drivers/dma-buf/dma-fence.c | 23 +- include/asm-generic/vmlinux.lds.h | 13 +- include/linux/completion.h | 124 +- include/linux/dept.h | 402 +++ include/linux/dept_ldt.h | 78 + include/linux/dept_sdt.h | 68 + include/linux/dept_unit_test.h | 67 + include/linux/dma-fence.h | 74 +- include/linux/hardirq.h | 3 + include/linux/irq-entry-common.h | 4 + include/linux/irqflags.h | 21 +- include/linux/local_lock_internal.h | 1 + include/linux/lockdep.h | 105 +- include/linux/lockdep_types.h | 3 + include/linux/mm_types.h | 4 + include/linux/mmu_notifier.h | 26 + include/linux/module.h | 5 + include/linux/mutex.h | 1 + include/linux/page-flags.h | 217 +- include/linux/pagemap.h | 37 +- include/linux/percpu-rwsem.h | 2 +- include/linux/percpu.h | 4 + include/linux/rcupdate_wait.h | 13 +- include/linux/rtmutex.h | 1 + include/linux/rwlock_types.h | 1 + include/linux/rwsem.h | 1 + include/linux/sched.h | 118 + include/linux/seqlock.h | 2 +- include/linux/spinlock_types_raw.h | 3 + include/linux/srcu.h | 2 +- include/linux/sunrpc/xprt.h | 9 +- include/linux/swait.h | 3 + include/linux/wait.h | 3 + include/linux/wait_bit.h | 3 + init/init_task.c | 2 + init/main.c | 2 + kernel/Makefile | 1 + kernel/cpu.c | 2 +- kernel/dependency/Makefile | 5 + kernel/dependency/dept.c | 3499 ++++++++++++++++++++++++++ kernel/dependency/dept_hash.h | 10 + kernel/dependency/dept_internal.h | 314 +++ kernel/dependency/dept_object.h | 13 + kernel/dependency/dept_proc.c | 94 + kernel/dependency/dept_unit_test.c | 173 ++ kernel/exit.c | 1 + kernel/fork.c | 2 + kernel/locking/lockdep.c | 33 + kernel/module/main.c | 19 + kernel/rcu/rcu.h | 1 + kernel/rcu/update.c | 5 +- kernel/sched/completion.c | 62 +- kernel/sched/core.c | 9 + kernel/workqueue.c | 3 + lib/Kconfig.debug | 48 + lib/debug_locks.c | 2 + lib/locking-selftest.c | 2 + mm/filemap.c | 38 + mm/mm_init.c | 3 + mm/mmu_notifier.c | 31 +- rust/helpers/completion.c | 5 + 63 files changed, 6602 insertions(+), 121 deletions(-) create mode 100644 Documentation/dev-tools/dept.rst create mode 100644 Documentation/dev-tools/dept_api.rst create mode 100644 include/linux/dept.h create mode 100644 include/linux/dept_ldt.h create mode 100644 include/linux/dept_sdt.h create mode 100644 include/linux/dept_unit_test.h create mode 100644 kernel/dependency/Makefile create mode 100644 kernel/dependency/dept.c create mode 100644 kernel/dependency/dept_hash.h create mode 100644 kernel/dependency/dept_internal.h create mode 100644 kernel/dependency/dept_object.h create mode 100644 kernel/dependency/dept_proc.c create mode 100644 kernel/dependency/dept_unit_test.c base-commit: 43dfc13ca972988e620a6edb72956981b75ab6b0 -- 2.17.1

1 week, 1 day

Prepare to Rage Quit (and Maybe Love It): Diving into Level Devil

by graceful.earthworm.hsos＠hidingmail.com

So, you're looking for a new game to sink your teeth into? Something challenging, maybe a little bit infuriating, and definitely memorable? Look no further than Level Devil. This deceptively simple platformer is a masterclass in trickery, constantly changing the rules and keeping you on your toes. But don't be intimidated! With a little patience (and maybe a stress ball), you can conquer its devilish design. https://leveldevilfull.com Gameplay: Expect the Unexpected At its core, Level Devil is a 2D platformer. You control a little pixelated character tasked with reaching the exit door in each level. Sounds easy, right? Wrong. The beauty (and the frustration) lies in the unpredictable nature of the environment. Platforms crumble beneath your feet, spikes appear out of nowhere, and the ground itself can vanish unexpectedly. Each level introduces new challenges, forcing you to adapt your strategy on the fly. You'll encounter moving platforms, disappearing blocks, and even gravity-defying puzzles. The real kicker? The layout of the levels often changes on each attempt, meaning memorization alone won't cut it. You need to be quick-witted and reactive. The charm of Level Devil is its lack of hand-holding. There are no tutorials, no hints, and no mercy. You're thrown straight into the deep end, forced to learn from your mistakes (and trust me, there will be plenty). That feeling of finally overcoming a particularly difficult section is incredibly rewarding. It's a game that demands your full attention and rewards persistence. Tips for Taming the Devil While Level Devil thrives on its unpredictability, here are a few tips to help you navigate its treacherous landscape: • Patience is Key: This game is designed to test your limits. Don't get discouraged by frequent deaths. Treat each attempt as a learning experience. • Observe Carefully: Before making a move, take a moment to scan the environment. Look for subtle cues that might indicate impending danger. • Embrace Failure: You will die. A lot. Embrace it as part of the learning process. Each death provides valuable insight into the level's design. • Don't Overthink It: Sometimes, the solution is simpler than you think. Avoid overcomplicating your approach. • Take Breaks: If you find yourself getting too frustrated, step away from the game for a while. Come back with a fresh perspective. • Listen to the Sound: The game’s audio cues often hint at upcoming dangers. Pay close attention! Level Devil utilizes sound design to enhance the experience (and sometimes, to cleverly mislead you!). Conclusion: A Test of Skill and Sanity Level Devil isn't for the faint of heart. It's a challenging and often frustrating experience. However, it's also incredibly rewarding. The constant surprises, the need for quick thinking, and the sheer satisfaction of overcoming its devilish design make it a truly unique and memorable game. If you're looking for a platformer that will push you to your limits and leave you feeling accomplished, then Level Devil is definitely worth a try. Just be prepared to rage quit... and then come back for more.

1 week, 4 days

Re: [PATCH] drm: docs: Remove item from TODO list

by Maxime Ripard

Hi, On Mon, Oct 23, 2023 at 10:25:50AM -0700, Doug Anderson wrote: > On Mon, Oct 23, 2023 at 9:31 AM Yuran Pereira <yuran.pereira(a)hotmail.com> wrote: > > > > Since "Clean up checks for already prepared/enabled in panels" has > > already been done and merged [1], I think there is no longer a need > > for this item to be in the gpu TODO. > > > > [1] https://patchwork.freedesktop.org/patch/551421/ > > > > Signed-off-by: Yuran Pereira <yuran.pereira(a)hotmail.com> > > --- > > Documentation/gpu/todo.rst | 25 ------------------------- > > 1 file changed, 25 deletions(-) > > It's not actually all done. It's in a bit of a limbo state right now, > unfortunately. I landed all of the "simple" cases where panels were > needlessly tracking prepare/enable, but the less simple cases are > still outstanding. > > Specifically the issue is that many panels have code to properly power > cycle themselves off at shutdown time and in order to do that they > need to keep track of the prepare/enable state. After a big, long > discussion [1] it was decided that we could get rid of all the panel > code handling shutdown if only all relevant DRM KMS drivers would > properly call drm_atomic_helper_shutdown(). > > I made an attempt to get DRM KMS drivers to call > drm_atomic_helper_shutdown() [2] [3] [4]. I was able to land the > patches that went through drm-misc, but currently many of the > non-drm-misc ones are blocked waiting for attention. > > ...so things that could be done to help out: > > a) Could review patches that haven't landed in [4]. Maybe adding a > Reviewed-by tag would help wake up maintainers? > > b) Could see if you can identify panels that are exclusively used w/ > DRM drivers that have already been converted and then we could post > patches for just those panels. I have no idea how easy this task would > be. Is it enough to look at upstream dts files by "compatible" string? I think it is, yes. Maxime

1 week, 5 days

Wordle Unlimited Game Guide for Endless Word Puzzle Fun

by thoughtless.stork.wxrl＠hidingmail.net

Introduction to Wordle Unlimited Experience Wordle Unlimited is an online word puzzle game that expands the classic word guessing concept into an endless format. Instead of waiting for a daily puzzle, players can enjoy continuous gameplay with unlimited attempts and unlimited rounds. This format makes it appealing for players who enjoy vocabulary challenges, logic thinking, and casual gaming without time restrictions. https://wordleunlimitedgame.org/ The main objective remains simple. Players try to guess a hidden five letter word within a limited number of attempts. After each guess, feedback is provided through color indicators that help narrow down the correct answer. This simple design combined with endless replay value makes Wordle Unlimited highly engaging for both beginners and experienced puzzle players. How Wordle Unlimited Gameplay Works Wordle Unlimited follows a straightforward set of rules that are easy to understand. Each round begins with a hidden word that players must discover. Players enter a five letter word as a guess, and the system responds with color coded hints. Green indicates a correct letter in the correct position. Yellow indicates a correct letter in the wrong position. Gray indicates a letter that is not part of the hidden word. These feedback signals guide players toward the correct answer step by step. Unlike traditional daily word puzzles, Wordle Unlimited allows continuous play without waiting periods. Players can restart instantly after finishing a round, making it suitable for practice, entertainment, or improving vocabulary skills. This unlimited structure also allows experimentation with different guessing strategies. Key Features of Wordle Unlimited One of the most important features of Wordle Unlimited is unlimited gameplay. Players are not restricted to a single puzzle per day, which increases engagement and learning opportunities. This feature is especially useful for users who enjoy repetitive practice or competitive improvement. Another key feature is accessibility. The game runs directly in a web browser, meaning no installation is required. It works on desktop computers, tablets, and mobile devices, making it convenient for users in different environments. Wordle Unlimited also maintains a simple interface. There are no complicated menus or distractions. The focus remains entirely on word solving. This minimal design helps players concentrate and improves the overall puzzle solving experience. Additionally, the game supports learning and vocabulary development. Players are exposed to different word patterns and letter combinations, which can help improve language skills over time. Effective Strategies for Winning Wordle Unlimited A strong strategy in Wordle Unlimited begins with choosing a good starting word. Many players select words that contain common vowels and frequently used consonants. This approach increases the chance of identifying correct letters early in the game. Another effective strategy is to avoid repeating incorrect letters. Once a letter is marked as gray, it is usually best to exclude it from future guesses. This helps narrow down possibilities more efficiently. Players also benefit from analyzing letter placement carefully. When a letter is marked yellow, it should be repositioned in the next guess. This process of elimination is essential for solving puzzles in fewer attempts. It is also helpful to think in word patterns rather than random guesses. English words often follow predictable structures, and recognizing these patterns can significantly improve success rates. Finally, patience plays an important role. Rushing guesses can lead to repeated mistakes. Taking time to evaluate feedback from each attempt leads to more accurate solutions. Benefits of Playing Wordle Unlimited Regularly Playing Wordle Unlimited regularly offers several cognitive benefits. One major advantage is vocabulary improvement. Players are exposed to a wide range of words, which helps expand language knowledge over time. Another benefit is mental exercise. Word puzzle games stimulate logical thinking, pattern recognition, and memory recall. These skills are useful in both academic and professional contexts. Wordle Unlimited also provides stress relief for many players. The simple structure and short gameplay sessions make it a relaxing activity that can be enjoyed during breaks or free time. In addition, the unlimited nature of the game allows continuous practice. This is especially beneficial for players who want to improve performance or challenge themselves with faster solving times. Social interaction is another indirect benefit. Many players enjoy sharing results or competing with friends, which adds a fun and competitive element to the experience. Why Wordle Unlimited Remains Popular The popularity of Wordle Unlimited comes from its balance of simplicity and challenge. It does not require advanced gaming skills, yet it still offers a satisfying mental challenge. This combination makes it accessible to a wide audience. The unlimited format also contributes to its popularity. Players are no longer restricted by daily limits, which means they can engage with the game whenever they want. This flexibility aligns well with modern digital habits. Another reason for its popularity is its quick gameplay loop. Each round can be completed in a short time, making it ideal for casual entertainment. Despite its simplicity, the game continues to offer new challenges with every hidden word. Conclusion on Wordle Unlimited Experience Wordle Unlimited delivers a simple yet highly engaging word puzzle experience that appeals to players of all ages. With unlimited gameplay, easy rules, and strong cognitive benefits, it stands out as an effective and enjoyable word game.

2 weeks

Shred Some Slopes: Getting the Hang of Snow Rider 3D

by careful.earthworm.usil＠hidingmail.com

Feeling the need for speed and a bit of winter fun, even when the weather outside is frightful? Then maybe it’s time to check out Snow Rider 3D. This simple but surprisingly addictive game offers a thrill of downhill skiing and snowboarding right from your browser, no downloads required. Let’s break down how to jump in and start enjoying this surprisingly engaging title. https://snowriderfree.com/ Gameplay: Simple Controls, Endless Possibilities The core gameplay of Snow Rider 3D is deceptively straightforward. You control your character's direction using the left and right arrow keys (or A and D). Your objective? Navigate through a series of procedurally generated slopes littered with obstacles. These obstacles range from simple ramps and rails to more challenging hazards like trees, snowdrifts, and even abandoned shacks. The beauty of Snow Rider 3D lies in its physics. While simple, they feel surprisingly realistic. You'll need to anticipate turns, adjust your speed, and time your jumps to successfully navigate the terrain. A crash will reset you to the beginning of the course, so precision and patience are key. The game offers different levels, each presenting a unique challenge. Some focus on speed and long jumps, while others demand skillful maneuvering through tight spaces. As you progress, you unlock new skins and sleds, adding a touch of customization to your experience. Think of it as a casual time-killer that can quickly turn into an hour-long obsession! Tips for Mastering the Mountain: Alright, so you're ready to hit the slopes. Here are a few tips to help you improve your runs and avoid those frustrating wipeouts: Practice Makes Perfect: Don't get discouraged by early crashes. The more you play, the better you'll understand the physics and learn to anticipate the terrain. Master the Turns: Smooth, controlled turns are essential for maintaining speed and avoiding obstacles. Practice feathering the arrow keys to make subtle adjustments. Timing is Everything: When approaching jumps and ramps, pay close attention to your speed and angle. A well-timed jump can make all the difference. Don't Be Afraid to Slow Down: Sometimes, the fastest route isn't the safest. Don't be afraid to ease off the gas and navigate tricky sections with caution. Consider looking up guides for specific levels of Snow Rider 3D at websites like Snow Rider 3D if you’re really struggling. Experiment with Sleds and Skins: Different sleds may offer slight variations in handling. Try out different options to find one that suits your playstyle. Conclusion: A Fun and Accessible Winter Escape Snow Rider 3D is a surprisingly addictive and accessible game that’s perfect for a quick dose of winter fun. It's simple controls and challenging gameplay make it easy to pick up and play, while its procedural generation ensures that each run is a unique experience. So, whether you're looking for a casual time-killer or a challenging skill-based game, Snow Rider 3D is definitely worth checking out.

2 weeks, 1 day

Bake Your Way to Billions: A Look at the Addictive World of Store Management Games

by hot.meerkat.lloh＠hidingmail.net

Ever dreamed of running your own bustling enterprise, watching your profits soar, and building an empire from humble beginnings? If so, you've likely stumbled upon the fascinating and surprisingly addictive world of store management games. These titles offer a unique blend of strategy, incremental growth, and the satisfying feeling of seeing your hard work pay off. And when it comes to the purest, most delightful form of this genre, one game stands out: https://cookieclickers.io/ The Sweet Simplicity of Cookie Clicker: A Gateway to Management At its heart, Cookie Clicker is incredibly simple. You start with a single, humble cookie, and your goal is to click it to generate more cookies. These initial clicks are crucial, as they fund your first upgrades. Soon, you’ll be able to purchase "grandmas," who automatically bake cookies for you, freeing up your clicking finger. From there, the sky's the limit! You'll acquire farms, factories, mines, and even portals to other dimensions, all dedicated to the singular purpose of baking more and more cookies. What makes Cookie Clicker so captivating is its elegant progression system. Each new upgrade and building provides a tangible boost to your cookie production, creating a satisfying feedback loop. The numbers on your screen grow exponentially, transforming from humble dozens to mind-boggling septillions and beyond. It’s a masterclass in incremental design, making every new purchase feel impactful and exciting. Beyond the Click: Strategic Thinking and Exponential Growth While the initial appeal of Cookie Clicker might be the simple act of clicking, true mastery lies in strategic decision-making. As your cookie empire expands, you'll be faced with choices: Upgrade Prioritization: Should you invest in another Grandma, a new farm, or a powerful upgrade that boosts all your existing structures? Understanding the cost-benefit analysis of each option is key. Synergies: Many upgrades have synergistic effects, meaning they become more powerful when paired with specific buildings. Discovering these combinations is a delightful puzzle. Ascension and Prestige: Eventually, you’ll unlock the ability to “ascend,” resetting your game but granting you powerful "heavenly chips" that provide permanent bonuses. This meta-progression adds a whole new layer of long-term strategy, encouraging you to rethink your approach with each new playthrough. These elements elevate Cookie Clicker from a simple clicking game to a genuinely engaging management simulation. It teaches you about exponential growth, compound interest (in a fun, cookie-filled way!), and the satisfaction of building something from nothing. Tips for Aspiring Cookie Tycoons If you’re ready to dive into the sweet, sweet world of Cookie Clicker, here are a few friendly tips to get you started: Don't Be Afraid to Click! In the early game, your clicks are your most valuable resource. Keep that finger moving! Invest in Grandmas Early: They're your first step towards automation and a steady cookie income. Always Buy Upgrades: The small boosts they provide add up quickly and are often more cost-effective than new buildings in the short term. Look for Golden Cookies: These appear randomly and offer temporary, powerful buffs. Clicking them can drastically boost your production! Consider Ascending: While it seems daunting to reset your progress, the permanent bonuses you gain make future runs much faster and more efficient. The Endless Appeal of Automation Cookie Clicker, and store management games in general, tap into a fundamental human desire: the joy of creation and the satisfaction of watching systems work efficiently. There's a particular kind of quiet pleasure in setting up a well-oiled machine and observing its output multiply. So, if you're looking for a game that's easy to pick up, surprisingly deep, and immensely satisfying, give Cookie Clicker a try. You might just find yourself baking billions before you know it!

2 weeks, 1 day

Why should you buy a dachshund puppy?

by Chong Criston

3 weeks

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