kernel/linux.git/include/linux/wait.h, branch v6.19.11

sched/wait: Add wait_event_state_exclusive()

2025-08-27T12:29:43+00:00

Allows exclusive waits with a custom @state. Signed-off-by: Sergey Senozhatsky Acked-by: Peter Zijlstra (Intel) Signed-off-by: Miklos Szeredi

sched/wait: Add a waitqueue helper for fully exclusive priority waiters

2025-06-23T16:50:58+00:00

Add a waitqueue helper to add a priority waiter that requires exclusive wakeups, i.e. that requires that it be the _only_ priority waiter. The API will be used by KVM to ensure that at most one of KVM's irqfds is bound to a single eventfd (across the entire kernel). Open code the helper instead of using __add_wait_queue() so that the common path doesn't need to "handle" impossible failures. Cc: K Prateek Nayak Reviewed-by: K Prateek Nayak Tested-by: K Prateek Nayak Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250522235223.3178519-9-seanjc@google.com Signed-off-by: Sean Christopherson

Merge tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux

2025-03-27T01:08:55+00:00

Pull block updates from Jens Axboe: - Fixes for integrity handling - NVMe pull request via Keith: - Secure concatenation for TCP transport (Hannes) - Multipath sysfs visibility (Nilay) - Various cleanups (Qasim, Baruch, Wang, Chen, Mike, Damien, Li) - Correct use of 64-bit BARs for pci-epf target (Niklas) - Socket fix for selinux when used in containers (Peijie) - MD pull request via Yu: - fix recovery can preempt resync (Li Nan) - fix md-bitmap IO limit (Su Yue) - fix raid10 discard with REQ_NOWAIT (Xiao Ni) - fix raid1 memory leak (Zheng Qixing) - fix mddev uaf (Yu Kuai) - fix raid1,raid10 IO flags (Yu Kuai) - some refactor and cleanup (Yu Kuai) - Series cleaning up and fixing bugs in the bad block handling code - Improve support for write failure simulation in null_blk - Various lock ordering fixes - Fixes for locking for debugfs attributes - Various ublk related fixes and improvements - Cleanups for blk-rq-qos wait handling - blk-throttle fixes - Fixes for loop dio and sync handling - Fixes and cleanups for the auto-PI code - Block side support for hardware encryption keys in blk-crypto - Various cleanups and fixes * tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux: (105 commits) nvmet: replace max(a, min(b, c)) by clamp(val, lo, hi) nvme-tcp: fix selinux denied when calling sock_sendmsg nvmet: pci-epf: Always configure BAR0 as 64-bit nvmet: Remove duplicate uuid_copy nvme: zns: Simplify nvme_zone_parse_entry() nvmet: pci-epf: Remove redundant 'flush_workqueue()' calls nvmet-fc: Remove unused functions nvme-pci: remove stale comment nvme-fc: Utilise min3() to simplify queue count calculation nvme-multipath: Add visibility for queue-depth io-policy nvme-multipath: Add visibility for numa io-policy nvme-multipath: Add visibility for round-robin io-policy nvmet: add tls_concat and tls_key debugfs entries nvmet-tcp: support secure channel concatenation nvmet: Add 'sq' argument to alloc_ctrl_args nvme-fabrics: reset admin connection for secure concatenation nvme-tcp: request secure channel concatenation nvme-keyring: add nvme_tls_psk_refresh() nvme: add nvme_auth_derive_tls_psk() nvme: add nvme_auth_generate_digest() ...

wait: avoid spurious calls to prepare_to_wait_event() in ___wait_event()

2025-03-04T08:46:07+00:00

In vast majority of cases the condition determining whether the thread can proceed is true after the first wake up. However, even in that case the thread ends up calling into prepare_to_wait_event() again, suffering a spurious irq + lock trip. Then it calls into finish_wait() to unlink itself. Note that in case of a pending signal the work done by prepare_to_wait_event() gets ignored even without the change. pre-check the condition after waking up instead. Stats gathared during a kernel build: bpftrace -e 'kprobe:prepare_to_wait_event,kprobe:finish_wait \ { @[probe] = count(); }' @[kprobe:finish_wait]: 392483 @[kprobe:prepare_to_wait_event]: 778690 As in calls to prepare_to_wait_event() almost double calls to finish_wait(). This evens out with the patch. Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20250303230409.452687-4-mjguzik@gmail.com Signed-off-by: Christian Brauner

block: introduce init_wait_func()

2025-02-11T20:04:11+00:00

There is already a macro DEFINE_WAIT_FUNC() to declare a wait_queue_entry with a specified waking function. But there is not a counterpart for initializing one wait_queue_entry with a specified waking function. So introducing init_wait_func() for this, which also could be used in iocost and rq-qos. Using default_wake_function() in rq_qos_wait() to wake up waiters, which could remove ->task field from rq_qos_wait_data. Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Muchun Song Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20250208090416.38642-1-songmuchun@bytedance.com Signed-off-by: Jens Axboe

Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-20T00:35:06+00:00

Pull timer updates from Thomas Gleixner: "A rather large update for timekeeping and timers: - The final step to get rid of auto-rearming posix-timers posix-timers are currently auto-rearmed by the kernel when the signal of the timer is ignored so that the timer signal can be delivered once the corresponding signal is unignored. This requires to throttle the timer to prevent a DoS by small intervals and keeps the system pointlessly out of low power states for no value. This is a long standing non-trivial problem due to the lock order of posix-timer lock and the sighand lock along with life time issues as the timer and the sigqueue have different life time rules. Cure this by: - Embedding the sigqueue into the timer struct to have the same life time rules. Aside of that this also avoids the lookup of the timer in the signal delivery and rearm path as it's just a always valid container_of() now. - Queuing ignored timer signals onto a seperate ignored list. - Moving queued timer signals onto the ignored list when the signal is switched to SIG_IGN before it could be delivered. - Walking the ignored list when SIG_IGN is lifted and requeue the signals to the actual signal lists. This allows the signal delivery code to rearm the timer. This also required to consolidate the signal delivery rules so they are consistent across all situations. With that all self test scenarios finally succeed. - Core infrastructure for VFS multigrain timestamping This is required to allow the kernel to use coarse grained time stamps by default and switch to fine grained time stamps when inode attributes are actively observed via getattr(). These changes have been provided to the VFS tree as well, so that the VFS specific infrastructure could be built on top. - Cleanup and consolidation of the sleep() infrastructure - Move all sleep and timeout functions into one file - Rework udelay() and ndelay() into proper documented inline functions and replace the hardcoded magic numbers by proper defines. - Rework the fsleep() implementation to take the reality of the timer wheel granularity on different HZ values into account. Right now the boundaries are hard coded time ranges which fail to provide the requested accuracy on different HZ settings. - Update documentation for all sleep/timeout related functions and fix up stale documentation links all over the place - Fixup a few usage sites - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP clocks A system can have multiple PTP clocks which are participating in seperate and independent PTP clock domains. So far the kernel only considers the PTP clock which is based on CLOCK TAI relevant as that's the clock which drives the timekeeping adjustments via the various user space daemons through adjtimex(2). The non TAI based clock domains are accessible via the file descriptor based posix clocks, but their usability is very limited. They can't be accessed fast as they always go all the way out to the hardware and they cannot be utilized in the kernel itself. As Time Sensitive Networking (TSN) gains traction it is required to provide fast user and kernel space access to these clocks. The approach taken is to utilize the timekeeping and adjtimex(2) infrastructure to provide this access in a similar way how the kernel provides access to clock MONOTONIC, REALTIME etc. Instead of creating a duplicated infrastructure this rework converts timekeeping and adjtimex(2) into generic functionality which operates on pointers to data structures instead of using static variables. This allows to provide time accessors and adjtimex(2) functionality for the independent PTP clocks in a subsequent step. - Consolidate hrtimer initialization hrtimers are set up by initializing the data structure and then seperately setting the callback function for historical reasons. That's an extra unnecessary step and makes Rust support less straight forward than it should be. Provide a new set of hrtimer_setup*() functions and convert the core code and a few usage sites of the less frequently used interfaces over. The bulk of the htimer_init() to hrtimer_setup() conversion is already prepared and scheduled for the next merge window. - Drivers: - Ensure that the global timekeeping clocksource is utilizing the cluster 0 timer on MIPS multi-cluster systems. Otherwise CPUs on different clusters use their cluster specific clocksource which is not guaranteed to be synchronized with other clusters. - Mostly boring cleanups, fixes, improvements and code movement" * tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits) posix-timers: Fix spurious warning on double enqueue versus do_exit() clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties clocksource/drivers/gpx: Remove redundant casts clocksource/drivers/timer-ti-dm: Fix child node refcount handling dt-bindings: timer: actions,owl-timer: convert to YAML clocksource/drivers/ralink: Add Ralink System Tick Counter driver clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource clocksource/drivers/timer-ti-dm: Don't fail probe if int not found clocksource/drivers:sp804: Make user selectable clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions hrtimers: Delete hrtimer_init_on_stack() alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack() io_uring: Switch to use hrtimer_setup_on_stack() sched/idle: Switch to use hrtimer_setup_on_stack() hrtimers: Delete hrtimer_init_sleeper_on_stack() wait: Switch to use hrtimer_setup_sleeper_on_stack() timers: Switch to use hrtimer_setup_sleeper_on_stack() net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack() futex: Switch to use hrtimer_setup_sleeper_on_stack() fs/aio: Switch to use hrtimer_setup_sleeper_on_stack() ...

wait: Switch to use hrtimer_setup_sleeper_on_stack()

2024-11-07T01:47:06+00:00

hrtimer_setup_sleeper_on_stack() replaces hrtimer_init_sleeper_on_stack() to keep the naming convention consistent. Convert the usage site over to it. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/fc91182375df81120a88dbe0263267e24d1bf19e.1730386209.git.namcao@linutronix.de

epoll: Add synchronous wakeup support for ep_poll_callback

2024-10-22T09:16:59+00:00

Now, the epoll only use wake_up() interface to wake up task. However, sometimes, there are epoll users which want to use the synchronous wakeup flag to hint the scheduler, such as Android binder driver. So add a wake_up_sync() define, and use the wake_up_sync() when the sync is true in ep_poll_callback(). Co-developed-by: Jing Xia Signed-off-by: Jing Xia Signed-off-by: Xuewen Yan Link: https://lore.kernel.org/r/20240426080548.8203-1-xuewen.yan@unisoc.com Tested-by: Brian Geffon Reviewed-by: Brian Geffon Reported-by: Benoit Lize Signed-off-by: Christian Brauner

wait: Remove uapi header file from main header file

2023-12-21T00:26:31+00:00

There's really no overlap between uapi/linux/wait.h and linux/wait.h. There are two files which rely on the uapi file being implcitly included, so explicitly include it there and remove it from the main header file. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Kent Overstreet Reviewed-by: Christian Brauner

sched: remove wait bookmarks

2023-10-18T21:34:18+00:00

There are no users of wait bookmarks left, so simplify the wait code by removing them. Link: https://lkml.kernel.org/r/20231010035829.544242-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Ingo Molnar Cc: Benjamin Segall Cc: Bin Lai Cc: Daniel Bristot de Oliveira Cc: Dietmar Eggemann Cc: Ingo Molnar Cc: Juri Lelli Cc: Mel Gorman Cc: Peter Zijlstra Cc: Steven Rostedt (Google) Cc: Valentin Schneider Cc: Vincent Guittot Signed-off-by: Andrew Morton