Commit Graph

1031339 Commits

Author SHA1 Message Date
Pavel Begunkov
48dcd38d73 io_uring: optimise iowq refcounting
If a requests is forwarded into io-wq, there is a good chance it hasn't
been refcounted yet and we can save one req_ref_get() by setting the
refcount number to the right value directly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2d53f4449faaf73b4a4c5de667fc3c176d974860.1628981736.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:37 -06:00
Jens Axboe
a141dd896f io_uring: correct __must_hold annotation
io_req_free_batch() has a __must_hold annotation referencing a
request being passed in, but we're passing in the context.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:37 -06:00
Hao Xu
41a5169c23 io_uring: code clean for completion_lock in io_arm_poll_handler()
We can merge two spin_unlock() operations to one since we removed some
code not long ago.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:37 -06:00
Hao Xu
f552a27afe io_uring: remove files pointer in cancellation functions
When doing cancellation, we use a parameter to indicate where it's from
do_exit or exec. So a boolean value is good enough for this, remove the
struct files* as it is not necessary.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
[axboe: fixup io_uring_files_cancel for !CONFIG_IO_URING]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:37 -06:00
Hao Xu
a4aadd11ea io_uring: extract io_uring_files_cancel() in io_uring_task_cancel()
Extract io_uring_files_cancel() call in io_uring_task_cancel() to make
io_uring_files_cancel() and io_uring_task_cancel() coherent and easy to
read.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:37 -06:00
Pavel Begunkov
fd08e5309b io_uring: optimise hot path of ltimeout prep
io_prep_linked_timeout() grew too heavy and compiler now refuse to
inline the function. Help it by splitting in two and annotating with
inline.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/560636717a32e9513724f09b9ecaace942dde4d4.1628705069.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:37 -06:00
Pavel Begunkov
20e60a3832 io_uring: skip request refcounting
As submission references are gone, there is only one initial reference
left. Instead of actually doing atomic refcounting, add a flag
indicating whether we're going to take more refs or doing any other sync
magic. The flag should be set before the request may get used in
parallel.

Together with the previous patch it saves 2 refcount atomics per request
for IOPOLL and IRQ completions, and 1 atomic per req for inline
completions, with some exceptions. In particular, currently, there are
three cases, when the refcounting have to be enabled:
- Polling, including apoll. Because double poll entries takes a ref.
  Might get relaxed in the near future.
- Link timeouts, enabled for both, the timeout and the request it's
  bound to, because they work in-parallel and we need to synchronise
  to cancel one of them on completion.
- When a request gets in io-wq, because it doesn't hold uring_lock and
  we need guarantees of submission references.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8b204b6c5f6643062270a1913d6d3a7f8f795fd9.1628705069.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Pavel Begunkov
5d5901a343 io_uring: remove submission references
Requests are by default given with two references, submission and
completion. Completion references are straightforward, they represent
request ownership and are put when a request is completed or so.
Submission references are a bit more trickier. They're needed when
io_issue_sqe() followed deep into the submission stack (e.g. in fs,
block, drivers, etc.), request may have given away for concurrent
execution or already completed, and the code unwinding back to
io_issue_sqe() may be accessing some pieces of our requests, e.g.
file or iov.

Now, we prevent such async/in-depth completions by pushing requests
through task_work. Punting to io-wq is also done through task_works,
apart from a couple of cases with a pretty well known context. So,
there're two cases:
1) io_issue_sqe() from the task context and protected by ->uring_lock.
Either requests return back to io_uring or handed to task_work, which
won't be executed because we're currently controlling that task. So,
we can be sure that requests are staying alive all the time and we don't
need submission references to pin them.

2) io_issue_sqe() from io-wq, which doesn't hold the mutex. The role of
submission reference is played by io-wq reference, which is put by
io_wq_submit_work(). Hence, it should be fine.

Considering that, we can carefully kill the submission reference.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6b68f1c763229a590f2a27148aee77767a8d7750.1628705069.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Pavel Begunkov
91c2f69783 io_uring: remove req_ref_sub_and_test()
Soon, we won't need to put several references at once, remove
req_ref_sub_and_test() and @nr argument from io_put_req_deferred(),
and put the rest of the references by hand.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1868c7554108bff9194fb5757e77be23fadf7fc0.1628705069.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Pavel Begunkov
21c843d582 io_uring: move req_ref_get() and friends
Move all request refcount helpers to avoid forward declarations in the
future.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89fd36f6f3fe5b733dfe4546c24725eee40df605.1628705069.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Jens Axboe
79ebeaee8a io_uring: remove IRQ aspect of io_ring_ctx completion lock
We have no hard/soft IRQ users of this lock left, remove any IRQ
disabling/saving and restoring when grabbing this lock.

This is straight forward with no users entering with IRQs disabled
anymore, the only thing to look out for is the waitqueue poll head
lock which nests inside the completion lock. That needs IRQs disabled,
and hence we have to do that now instead of relying on the outer lock
doing so.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Jens Axboe
8ef12efe26 io_uring: run regular file completions from task_work
This is in preparation to making the completion lock work outside of
hard/soft IRQ context.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Jens Axboe
89b263f6d5 io_uring: run linked timeouts from task_work
This is in preparation to making the completion lock work outside of
hard/soft IRQ context.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Jens Axboe
89850fce16 io_uring: run timeouts from task_work
This is in preparation to making the completion lock work outside of
hard/soft IRQ context.

Add a timeout_lock to handle the ordering of timeout completions or
cancelations with the timeouts actually triggering.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Pavel Begunkov
62906e89e6 io_uring: remove file batch-get optimisation
For requests with non-fixed files, instead of grabbing just one
reference, we get by the number of left requests, so the following
requests using the same file can take it without atomics.

However, it's not all win. If there is one request in the middle
not using files or having a fixed file, we'll need to put back the left
references. Even worse if an application submits requests dealing with
different files, it will do a put for each new request, so doubling the
number of atomics needed. Also, even if not used, it's still takes some
cycles in the submission path.

If a file used many times, it rather makes sense to pre-register it, if
not, we may fall in the described pitfall. So, this optimisation is a
matter of use case. Go with the simpliest code-wise way, remove it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Pavel Begunkov
6294f3686b io_uring: clean up tctx_task_work()
After recent fixes, tctx_task_work() always does proper spinlocking
before looking into ->task_list, so now we don't need atomics for
->task_state, replace it with non-atomic task_running using the critical
section.

Tide it up, combine two separate block with spinlocking, and always try
to splice in there, so we do less locking when new requests are arriving
during the function execution.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
[axboe: fix missing ->task_running reset on task_work_add() failure]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:32 -06:00
Pavel Begunkov
5d70904367 io_uring: inline io_poll_remove_waitqs
Inline io_poll_remove_waitqs() into its only user and clean it up.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2f1a91a19ffcd591531dc4c61e2f11c64a2d6a6d.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:26 -06:00
Pavel Begunkov
90f67366cb io_uring: remove extra argument for overflow flush
Unlike __io_cqring_overflow_flush(), nobody does forced flushing with
io_cqring_overflow_flush(), so removed the argument from it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7594f869ca41b7cfb5a35a3c7c2d402242834e9e.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:10:19 -06:00
Pavel Begunkov
cd0ca2e048 io_uring: inline struct io_comp_state
Inline struct io_comp_state into struct io_submit_state. They are
already coupled tightly, together with mixed responsibilities it
only brings confusion having them separately.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e55bba77426b399e3a2e54e3c6c267c6a0fc4b57.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:09:48 -06:00
Pavel Begunkov
bb943b8265 io_uring: use inflight_entry instead of compl.list
req->compl.list is used to cache freed requests, and so can't overlap in
time with req->inflight_entry. So, use inflight_entry to link requests
and remove compl.list.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e430e79d22d70a190d718831bda7bfed1daf8976.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:09:43 -06:00
Pavel Begunkov
7255834ed6 io_uring: remove redundant args from cache_free
We don't use @tsk argument of io_req_cache_free(), remove it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6a28b4a58ee0aaf0db98e2179b9c9f06f9b0cca1.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:09:43 -06:00
Pavel Begunkov
c34b025f2d io_uring: cache __io_free_req()'d requests
Don't kfree requests in __io_free_req() but put them back into the
internal request cache. That makes allocations more sustainable and will
be used for refcounting optimisations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9f4950fbe7771c8d41799366d0a3a08ac3040236.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:09:43 -06:00
Pavel Begunkov
f56165e62f io_uring: move io_fallback_req_func()
Move io_fallback_req_func() to kill yet another forward declaration.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d0a8f9d9a0057ed761d6237167d51c9378798d2d.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:09:22 -06:00
Pavel Begunkov
e9dbe221f5 io_uring: optimise putting task struct
We cache all the reference to task + tctx, so if io_put_task() is
called by the corresponding task itself, we can save on atomics and
return the refs right back into the cache.

It's beneficial for all inline completions, and also iopolling, when
polling and submissions are done by the same task, including
SQPOLL|IOPOLL.

Note: io_uring_cancel_generic() can return refs to the cache as well,
so those should be flushed in the loop for tctx_inflight() to work
right.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6fe9646b3cb70e46aca1f58426776e368c8926b3.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:08:06 -06:00
Pavel Begunkov
af066f31eb io_uring: drop exec checks from io_req_task_submit
In case of on-exec io_uring cancellations, tasks already wait for all
submitted requests to get completed/cancelled, so we don't need to check
for ->in_execve separately.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/be8707049f10df9d20ca03dc4ca3316239b5e8e0.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:08:06 -06:00
Pavel Begunkov
bbbca09489 io_uring: kill unused IO_IOPOLL_BATCH
IO_IOPOLL_BATCH is not used, delete it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b2bdf19dbee2c9fc8865bbab9412135a14e24a64.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:08:06 -06:00
Pavel Begunkov
58d3be2c60 io_uring: improve ctx hang handling
If io_ring_exit_work() can't get it done in 5 minutes, something is
going very wrong, don't keep spinning at HZ / 20 rate, it doesn't help
and it may take much of CPU time if there is a lot of workers stuck as
such.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9e2d1ca81d569f6bc628af1a42ff6663bff7ce9c.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
d3fddf6ddd io_uring: deduplicate open iopoll check
Move IORING_SETUP_IOPOLL check into __io_openat_prep(), so both openat
and openat2 reuse it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9a73ce83e4ee60d011180ef177eecef8e87ff2a2.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
543af3a13d io_uring: inline io_free_req_deferred
Inline io_free_req_deferred(), there is no reason to keep it separated.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ce04b7180d4eac0d69dd00677b227eefe80c2cc5.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
b9bd2bea0f io_uring: move io_rsrc_node_alloc() definition
Move the function together with io_rsrc_node_ref_zero() in the source
file as it is to get rid of forward declarations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4d81f6f833e7d017860b24463a9a68b14a8a5ed2.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
6a290a1442 io_uring: move io_put_task() definition
Move the function in the source file as it is to get rid of forward
declarations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/33d917d69e4206557c75a5b98fe22bcdf77ce47d.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
e73c5c7cd3 io_uring: extract a helper for ctx quiesce
Refactor __io_uring_register() by extracting a helper responsible for
ctx queisce. Looks better and will make it easier to add more
optimisations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0339e0027504176be09237eefa7945bf9a6f153d.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
90291099f2 io_uring: optimise io_cqring_wait() hot path
Turns out we always init struct io_wait_queue in io_cqring_wait(), even
if it's not used after, i.e. there are already enough of CQEs. And often
it's exactly what happens, for instance, requests may have been
completed inline, or in case of io_uring_enter(submit=N, wait=1).

It shows up in my profiler, so optimise it by delaying the struct init.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6f1b81c60b947d165583dc333947869c3d85d037.1628471125.git.asml.silence@gmail.com
[axboe: fixed up for new cqring wait]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
282cdc8693 io_uring: add more locking annotations for submit
Add more annotations for submission path functions holding ->uring_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/128ec4185e26fbd661dd3a424aa66108ee8ff951.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
a2416e1ec2 io_uring: don't halt iopoll too early
IOPOLL users should care more about getting completions for requests
they submitted, but not in "device did/completed something". Currently,
io_do_iopoll() may return a positive number, which will instruct
io_iopoll_check() to break the loop and end the syscall, even if there
is not enough CQEs or none at all.

Don't return positive numbers, so io_iopoll_check() exits only when it
gets an actual error, need reschedule or got enough CQEs.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/641a88f751623b6758303b3171f0a4141f06726e.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
864ea921b0 io_uring: refactor io_alloc_req
Replace the main if of io_flush_cached_reqs() with inverted condition +
goto, so all the cases are handled in the same way. And also extract
io_preinit_req() to make it cleaner and easier to refer to.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1abcba1f7b55dc53bf1dbe95036e345ffb1d5b01.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:59 -06:00
Pavel Begunkov
8724dd8c83 io-wq: improve wq_list_add_tail()
Prepare nodes that we're going to add before actually linking them, it's
always safer and costs us nothing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f7e53f0c84c02ed6748c488ed0789b98f8cc6185.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Pavel Begunkov
2215bed924 io_uring: remove unnecessary PF_EXITING check
We prefer nornal task_works even if it would fail requests inside. Kill
a PF_EXITING check in io_req_task_work_add(), task_work_add() handles
well dying tasks, i.e. return error when can't enqueue due to late
stages of do_exit().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fc14297e8441cd8f5d1743a2488cf0df09bf48ac.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Pavel Begunkov
ebc11b6c6b io_uring: clean io-wq callbacks
Move io-wq callbacks closer to each other, so it's easier to work with
them, and rename io_free_work() into io_wq_free_work() for consistency.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/851bbc7f0f86f206d8c1333efee8bcb9c26e419f.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Pavel Begunkov
c97d8a0f68 io_uring: avoid touching inode in rw prep
If we use fixed files, we can be sure (almost) that REQ_F_ISREG is set.
However, for non-reg files io_prep_rw() still will look into inode to
double check, and that's expensive and can be avoided.

The only caveat is that it only currently works with 64+ bit
architectures, see FFS_ISREG, so we should consider that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0a62780c491ca2522cd52db4ae3f16e03aafed0f.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Pavel Begunkov
b191e2dfe5 io_uring: rename io_file_supports_async()
io_file_supports_async() checks whether a file supports nowait
operations, so "async" in the name is misleading. Rename it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/33d55b5ce43aa1884c637c1957f1e30d30dc3bec.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Pavel Begunkov
ac177053bb io_uring: inline fixed part of io_file_get()
Optimise io_file_get() with registered files, which is in a hot path,
by inlining parts of the function. Saves a function call, and
inefficiencies of passing arguments, e.g. evaluating
(sqe_flags & IOSQE_FIXED_FILE).

It couldn't have been done before as compilers were refusing to inline
it because of the function size.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/52115cd6ce28f33bd0923149c0e6cb611084a0b1.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Pavel Begunkov
042b0d85ea io_uring: use kvmalloc for fixed files
Instead of hand-coded two-level tables for registered files, allocate
them with kvmalloc(). In many cases small enough tables are enough, and
so can be kmalloc()'ed removing an extra memory load and a bunch of bit
logic instructions from the hot path. If the table is larger, we trade
off all the pros with a TLB-assisted memory lookup.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/280421d3b48775dabab773006bb5588c7b2dabc0.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Jens Axboe
5fd4617840 io_uring: be smarter about waking multiple CQ ring waiters
Currently we only wake the first waiter, even if we have enough entries
posted to satisfy multiple waiters. Improve that situation so that
every waiter knows how much the CQ tail has to advance before they can
be safely woken up.

With this change, if we have N waiters each asking for 1 event and we get
4 completions, then we wake up 4 waiters. If we have N waiters asking
for 2 completions and we get 4 completions, then we wake up the first
two. Previously, only the first waiter would've been woken up.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Jens Axboe
d3e9f732c4 io-wq: remove GFP_ATOMIC allocation off schedule out path
Daniel reports that the v5.14-rc4-rt4 kernel throws a BUG when running
stress-ng:

| [   90.202543] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:35
| [   90.202549] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2047, name: iou-wrk-2041
| [   90.202555] CPU: 5 PID: 2047 Comm: iou-wrk-2041 Tainted: G        W         5.14.0-rc4-rt4+ #89
| [   90.202559] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
| [   90.202561] Call Trace:
| [   90.202577]  dump_stack_lvl+0x34/0x44
| [   90.202584]  ___might_sleep.cold+0x87/0x94
| [   90.202588]  rt_spin_lock+0x19/0x70
| [   90.202593]  ___slab_alloc+0xcb/0x7d0
| [   90.202598]  ? newidle_balance.constprop.0+0xf5/0x3b0
| [   90.202603]  ? dequeue_entity+0xc3/0x290
| [   90.202605]  ? io_wqe_dec_running.isra.0+0x98/0xe0
| [   90.202610]  ? pick_next_task_fair+0xb9/0x330
| [   90.202612]  ? __schedule+0x670/0x1410
| [   90.202615]  ? io_wqe_dec_running.isra.0+0x98/0xe0
| [   90.202618]  kmem_cache_alloc_trace+0x79/0x1f0
| [   90.202621]  io_wqe_dec_running.isra.0+0x98/0xe0
| [   90.202625]  io_wq_worker_sleeping+0x37/0x50
| [   90.202628]  schedule+0x30/0xd0
| [   90.202630]  schedule_timeout+0x8f/0x1a0
| [   90.202634]  ? __bpf_trace_tick_stop+0x10/0x10
| [   90.202637]  io_wqe_worker+0xfd/0x320
| [   90.202641]  ? finish_task_switch.isra.0+0xd3/0x290
| [   90.202644]  ? io_worker_handle_work+0x670/0x670
| [   90.202646]  ? io_worker_handle_work+0x670/0x670
| [   90.202649]  ret_from_fork+0x22/0x30

which is due to the RT kernel not liking a GFP_ATOMIC allocation inside
a raw spinlock. Besides that not working on RT, doing any kind of
allocation from inside schedule() is kind of nasty and should be avoided
if at all possible.

This particular path happens when an io-wq worker goes to sleep, and we
need a new worker to handle pending work. We currently allocate a small
data item to hold the information we need to create a new worker, but we
can instead include this data in the io_worker struct itself and just
protect it with a single bit lock. We only really need one per worker
anyway, as we will have run pending work between to sleep cycles.

https://lore.kernel.org/lkml/20210804082418.fbibprcwtzyt5qax@beryllium.lan/
Reported-by: Daniel Wagner <dwagner@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 13:07:56 -06:00
Linus Torvalds
e22ce8eb63 Linux 5.14-rc7 2021-08-22 14:24:56 -07:00
Linus Torvalds
1bdc3d5be7 powerpc fixes for 5.14 #6
- Fix random crashes on some 32-bit CPUs by adding isync() after locking/unlocking KUEP
  - Fix intermittent crashes when loading modules with strict module RWX
  - Fix a section mismatch introduce by a previous fix.
 
 Thanks to: Christophe Leroy, Fabiano Rosas, Laurent Vivier, Murilo Opsfelder Araújo,
 Nathan Chancellor, Stan Johnson.
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Merge tag 'powerpc-5.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix random crashes on some 32-bit CPUs by adding isync() after
   locking/unlocking KUEP

 - Fix intermittent crashes when loading modules with strict module RWX

 - Fix a section mismatch introduce by a previous fix.

Thanks to Christophe Leroy, Fabiano Rosas, Laurent Vivier, Murilo
Opsfelder Araújo, Nathan Chancellor, and Stan Johnson.

h# -----BEGIN PGP SIGNATURE-----

* tag 'powerpc-5.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Fix set_memory_*() against concurrent accesses
  powerpc/32s: Fix random crashes by adding isync() after locking/unlocking KUEP
  powerpc/xive: Do not mark xive_request_ipi() as __init
2021-08-22 09:49:31 -07:00
Linus Torvalds
9ff50bf2f2 Two clk driver fixes
- Make the regulator state match the GDSC power domain state at boot
    on Qualcomm SoCs so that the regulator isn't turned off
    inadvertently.
 
  - Fix earlycon on i.MX6Q SoCs
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Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

Pull clk driver fixes from Stephen Boyd:

 - Make the regulator state match the GDSC power domain state at boot on
   Qualcomm SoCs so that the regulator isn't turned off inadvertently.

 - Fix earlycon on i.MX6Q SoCs

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: qcom: gdsc: Ensure regulator init state matches GDSC state
  clk: imx6q: fix uart earlycon unwork
2021-08-21 11:27:16 -07:00
Linus Torvalds
9085423f0e Char/Misc driver fixes for 5.14-rc7
Here are some small driver fixes for 5.14-rc7.
 
 They consist of:
 	- revert for an interconnect patch that was found to have
 	  problems.
 	- ipack tpci200 driver fixes for reported problems
 	- slimbus messaging and ngd fixes for reported problems.
 
 All are small and have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
 "Here are some small driver fixes for 5.14-rc7.

  They consist of:

   - revert for an interconnect patch that was found to have problems

   - ipack tpci200 driver fixes for reported problems

   - slimbus messaging and ngd fixes for reported problems

  All are small and have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  ipack: tpci200: fix memory leak in the tpci200_register
  ipack: tpci200: fix many double free issues in tpci200_pci_probe
  slimbus: ngd: reset dma setup during runtime pm
  slimbus: ngd: set correct device for pm
  slimbus: messaging: check for valid transaction id
  slimbus: messaging: start transaction ids from 1 instead of zero
  Revert "interconnect: qcom: icc-rpmh: Add BCMs to commit list in pre_aggregate"
2021-08-21 11:22:10 -07:00
Linus Torvalds
f4ff9e6b01 USB fix for 5.14-rc7
Here is a single USB typec tcpm fix for a reported problem for 5.14-rc7.
 It showed up in 5.13 and resolves an issue that Hans found.  It has been
 in linux-next this week with no reported problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'usb-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fix from Greg KH:
 "Here is a single USB typec tcpm fix for a reported problem for
  5.14-rc7. It showed up in 5.13 and resolves an issue that Hans found.
  It has been in linux-next this week with no reported problems"

* tag 'usb-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: typec: tcpm: Fix VDMs sometimes not being forwarded to alt-mode drivers
2021-08-21 11:10:06 -07:00