- 23 Aug, 2021 37 commits
-
-
Pavel Begunkov authored
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.comSigned-off-by:
Jens Axboe <axboe@kernel.dk>
-
Pavel Begunkov authored
Move all request refcount helpers to avoid forward declarations in the future. Signed-off-by:
-
Jens Axboe authored
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 authored
This is in preparation to making the completion lock work outside of hard/soft IRQ context. Signed-off-by: -
Jens Axboe authored
This is in preparation to making the completion lock work outside of hard/soft IRQ context. Signed-off-by: -
Jens Axboe authored
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: -
Pavel Begunkov authored
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 authored
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 authored
Inline io_poll_remove_waitqs() into its only user and clean it up. Signed-off-by:
-
Pavel Begunkov authored
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 authored
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 authored
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 authored
We don't use @tsk argument of io_req_cache_free(), remove it. Signed-off-by:
-
Pavel Begunkov authored
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 authored
Move io_fallback_req_func() to kill yet another forward declaration. Signed-off-by:
-
Pavel Begunkov authored
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 authored
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 authored
IO_IOPOLL_BATCH is not used, delete it. Signed-off-by:
-
Pavel Begunkov authored
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 authored
Move IORING_SETUP_IOPOLL check into __io_openat_prep(), so both openat and openat2 reuse it. Signed-off-by:
-
Pavel Begunkov authored
Inline io_free_req_deferred(), there is no reason to keep it separated. Signed-off-by:
-
Pavel Begunkov authored
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 authored
Move the function in the source file as it is to get rid of forward declarations. Signed-off-by:
-
Pavel Begunkov authored
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 authored
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 authored
Add more annotations for submission path functions holding ->uring_lock. Signed-off-by:
-
Pavel Begunkov authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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:
-
Jens Axboe authored
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 authored
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:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
-
- 22 Aug, 2021 2 commits
-
-
Linus Torvalds authored
-
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
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
-
- 21 Aug, 2021 1 commit
-
-
git://git.kernel.org/pub/scm/linux/kernel/git/clk/linuxLinus Torvalds authored
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
-
