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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-23 12:22:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-23 12:22:49 -0700 |
commit | 3a166bdbf3abc8ca2d7ffe7cffc5c7a65f260e62 (patch) | |
tree | 4ad32893212766f194397b195467edbc47e59e8e /kernel | |
parent | 1e57930e9f4083ad5854ab6eadffe790a8167fb4 (diff) | |
parent | 0e7579ca732a39cc377e17509dda9bfc4f6ba78e (diff) | |
download | lwn-3a166bdbf3abc8ca2d7ffe7cffc5c7a65f260e62.tar.gz lwn-3a166bdbf3abc8ca2d7ffe7cffc5c7a65f260e62.zip |
Merge tag 'for-5.19/io_uring-2022-05-22' of git://git.kernel.dk/linux-block
Pull io_uring updates from Jens Axboe:
"Here are the main io_uring changes for 5.19. This contains:
- Fixes for sparse type warnings (Christoph, Vasily)
- Support for multi-shot accept (Hao)
- Support for io_uring managed fixed files, rather than always
needing the applicationt o manage the indices (me)
- Fix for a spurious poll wakeup (Dylan)
- CQE overflow fixes (Dylan)
- Support more types of cancelations (me)
- Support for co-operative task_work signaling, rather than always
forcing an IPI (me)
- Support for doing poll first when appropriate, rather than always
attempting a transfer first (me)
- Provided buffer cleanups and support for mapped buffers (me)
- Improve how io_uring handles inflight SCM files (Pavel)
- Speedups for registered files (Pavel, me)
- Organize the completion data in a struct in io_kiocb rather than
keep it in separate spots (Pavel)
- task_work improvements (Pavel)
- Cleanup and optimize the submission path, in general and for
handling links (Pavel)
- Speedups for registered resource handling (Pavel)
- Support sparse buffers and file maps (Pavel, me)
- Various fixes and cleanups (Almog, Pavel, me)"
* tag 'for-5.19/io_uring-2022-05-22' of git://git.kernel.dk/linux-block: (111 commits)
io_uring: fix incorrect __kernel_rwf_t cast
io_uring: disallow mixed provided buffer group registrations
io_uring: initialize io_buffer_list head when shared ring is unregistered
io_uring: add fully sparse buffer registration
io_uring: use rcu_dereference in io_close
io_uring: consistently use the EPOLL* defines
io_uring: make apoll_events a __poll_t
io_uring: drop a spurious inline on a forward declaration
io_uring: don't use ERR_PTR for user pointers
io_uring: use a rwf_t for io_rw.flags
io_uring: add support for ring mapped supplied buffers
io_uring: add io_pin_pages() helper
io_uring: add buffer selection support to IORING_OP_NOP
io_uring: fix locking state for empty buffer group
io_uring: implement multishot mode for accept
io_uring: let fast poll support multishot
io_uring: add REQ_F_APOLL_MULTISHOT for requests
io_uring: add IORING_ACCEPT_MULTISHOT for accept
io_uring: only wake when the correct events are set
io_uring: avoid io-wq -EAGAIN looping for !IOPOLL
...
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/task_work.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c index c59e1a49bc40..dff75bcde151 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -12,12 +12,22 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */ * @notify: how to notify the targeted task * * Queue @work for task_work_run() below and notify the @task if @notify - * is @TWA_RESUME or @TWA_SIGNAL. @TWA_SIGNAL works like signals, in that the - * it will interrupt the targeted task and run the task_work. @TWA_RESUME - * work is run only when the task exits the kernel and returns to user mode, - * or before entering guest mode. Fails if the @task is exiting/exited and thus - * it can't process this @work. Otherwise @work->func() will be called when the - * @task goes through one of the aforementioned transitions, or exits. + * is @TWA_RESUME, @TWA_SIGNAL, or @TWA_SIGNAL_NO_IPI. + * + * @TWA_SIGNAL works like signals, in that the it will interrupt the targeted + * task and run the task_work, regardless of whether the task is currently + * running in the kernel or userspace. + * @TWA_SIGNAL_NO_IPI works like @TWA_SIGNAL, except it doesn't send a + * reschedule IPI to force the targeted task to reschedule and run task_work. + * This can be advantageous if there's no strict requirement that the + * task_work be run as soon as possible, just whenever the task enters the + * kernel anyway. + * @TWA_RESUME work is run only when the task exits the kernel and returns to + * user mode, or before entering guest mode. + * + * Fails if the @task is exiting/exited and thus it can't process this @work. + * Otherwise @work->func() will be called when the @task goes through one of + * the aforementioned transitions, or exits. * * If the targeted task is exiting, then an error is returned and the work item * is not queued. It's up to the caller to arrange for an alternative mechanism @@ -53,6 +63,9 @@ int task_work_add(struct task_struct *task, struct callback_head *work, case TWA_SIGNAL: set_notify_signal(task); break; + case TWA_SIGNAL_NO_IPI: + __set_notify_signal(task); + break; default: WARN_ON_ONCE(1); break; |