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2024-04-15io_uring: move mapping/allocation helpers to a separate fileJens Axboe
Move the related code from io_uring.c into memmap.c. No functional changes in this patch, just cleaning it up a bit now that the full transition is done. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: use unpin_user_pages() where appropriateJens Axboe
There are a few cases of open-rolled loops around unpin_user_page(), use the generic helper instead. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/kbuf: use vm_insert_pages() for mmap'ed pbuf ringJens Axboe
Rather than use remap_pfn_range() for this and manually free later, switch to using vm_insert_page() and have it Just Work. This requires a bit of effort on the mmap lookup side, as the ctx uring_lock isn't held, which otherwise protects buffer_lists from being torn down, and it's not safe to grab from mmap context that would introduce an ABBA deadlock between the mmap lock and the ctx uring_lock. Instead, lookup the buffer_list under RCU, as the the list is RCU freed already. Use the existing reference count to determine whether it's possible to safely grab a reference to it (eg if it's not zero already), and drop that reference when done with the mapping. If the mmap reference is the last one, the buffer_list and the associated memory can go away, since the vma insertion has references to the inserted pages at that point. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: unify io_pin_pages()Jens Axboe
Move it into io_uring.c where it belongs, and use it in there as well rather than have two implementations of this. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: use vmap() for ring mappingJens Axboe
This is the last holdout which does odd page checking, convert it to vmap just like what is done for the non-mmap path. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: get rid of remap_pfn_range() for mapping rings/sqesJens Axboe
Rather than use remap_pfn_range() for this and manually free later, switch to using vm_insert_pages() and have it Just Work. If possible, allocate a single compound page that covers the range that is needed. If that works, then we can just use page_address() on that page. If we fail to get a compound page, allocate single pages and use vmap() to map them into the kernel virtual address space. This just covers the rings/sqes, the other remaining user of the mmap remap_pfn_range() user will be converted separately. Once that is done, we can kill the old alloc/free code. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: Remove the now superfluous sentinel elements from ctl_table arrayJoel Granados
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel element from kernel_io_uring_disabled_table Signed-off-by: Joel Granados <j.granados@samsung.com> Link: https://lore.kernel.org/r/20240328-jag-sysctl_remset_misc-v1-6-47c1463b3af2@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: Remove unused functionJiapeng Chong
The function are defined in the io_uring.c file, but not called elsewhere, so delete the unused function. io_uring/io_uring.c:646:20: warning: unused function '__io_cq_unlock'. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=8660 Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/20240328022324.78029-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: refill request cache in memory orderJens Axboe
The allocator will generally return memory in order, but __io_alloc_req_refill() then adds them to a stack and we'll extract them in the opposite order. This obviously isn't a huge deal, but: 1) it makes debugging easier when they are in order 2) keeping them in-order is the right thing to do 3) reduces the code for adding them to the stack Just add them in reverse to the stack. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/poll: shrink alloc cache size to 32Jens Axboe
This should be plenty, rather than the default of 128, and matches what we have on the rsrc and futex side as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/alloc_cache: switch to array based cachingJens Axboe
Currently lists are being used to manage this, but best practice is usually to have these in an array instead as that it cheaper to manage. Outside of that detail, games are also played with KASAN as the list is inside the cached entry itself. Finally, all users of this need a struct io_cache_entry embedded in their struct, which is union'ized with something else in there that isn't used across the free -> realloc cycle. Get rid of all of that, and simply have it be an array. This will not change the memory used, as we're just trading an 8-byte member entry for the per-elem array size. This reduces the overhead of the recycled allocations, and it reduces the amount of code code needed to support recycling to about half of what it currently is. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: drop ->prep_async()Jens Axboe
It's now unused, drop the code related to it. This includes the io_issue_defs->manual alloc field. While in there, and since ->async_size is now being used a bit more frequently and in the issue path, move it to io_issue_defs[]. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/uring_cmd: switch to always allocating async dataJens Axboe
Basic conversion ensuring async_data is allocated off the prep path. Adds a basic alloc cache as well, as passthrough IO can be quite high in rate. Tested-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/rw: always setup io_async_rw for read/write requestsJens Axboe
read/write requests try to put everything on the stack, and then alloc and copy if a retry is needed. This necessitates a bunch of nasty code that deals with intermediate state. Get rid of this, and have the prep side setup everything that is needed upfront, which greatly simplifies the opcode handlers. This includes adding an alloc cache for io_async_rw, to make it cheap to handle. In terms of cost, this should be basically free and transparent. For the worst case of {READ,WRITE}_FIXED which didn't need it before, performance is unaffected in the normal peak workload that is being used to test that. Still runs at 122M IOPS. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: remove timeout/poll specific cancelationsJens Axboe
For historical reasons these were special cased, as they were the only ones that needed cancelation. But now we handle cancelations generally, and hence there's no need to check for these in io_ring_ctx_wait_and_kill() when io_uring_try_cancel_requests() handles both these and the rest as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: flush delayed fallback task_work in cancelationJens Axboe
Just like we run the inline task_work, ensure we also factor in and run the fallback task_work. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: refactor io_req_complete_post()Pavel Begunkov
Make io_req_complete_post() to push all IORING_SETUP_IOPOLL requests to task_work, it's much cleaner and should normally happen. We couldn't do it before because there was a possibility of looping in complete_post() -> tw -> complete_post() -> ... Also, unexport the function and inline __io_req_complete_post(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/ea19c032ace3e0dd96ac4d991a063b0188037014.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: remove current check from complete_postPavel Begunkov
task_work execution is now always locked, and we shouldn't get into io_req_complete_post() from them. That means that complete_post() is always called out of the original task context and we don't even need to check current. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/24ec27f27db0d8f58c974d8118dca1d345314ddc.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: get rid of intermediate aux cqe cachesPavel Begunkov
io_post_aux_cqe(), which is used for multishot requests, delays completions by putting CQEs into a temporary array for the purpose completion lock/flush batching. DEFER_TASKRUN doesn't need any locking, so for it we can put completions directly into the CQ and defer post completion handling with a flag. That leaves !DEFER_TASKRUN, which is not that interesting / hot for multishot requests, so have conditional locking with deferred flush for them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/b1d05a81fd27aaa2a07f9860af13059e7ad7a890.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: refactor io_fill_cqe_req_auxPavel Begunkov
The restriction on multishot execution context disallowing io-wq is driven by rules of io_fill_cqe_req_aux(), it should only be called in the master task context, either from the syscall path or in task_work. Since task_work now always takes the ctx lock implying IO_URING_F_COMPLETE_DEFER, we can just assume that the function is always called with its defer argument set to true. Kill the argument. Also rename the function for more consistency as "fill" in CQE related functions was usually meant for raw interfaces only copying data into the CQ without any locking, waking the user and other accounting "post" functions take care of. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/93423d106c33116c7d06bf277f651aa68b427328.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: remove struct io_tw_state::lockedPavel Begunkov
ctx is always locked for task_work now, so get rid of struct io_tw_state::locked. Note I'm stopping one step before removing io_tw_state altogether, which is not empty, because it still serves the purpose of indicating which function is a tw callback and forcing users not to invoke them carelessly out of a wrong context. The removal can always be done later. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: force tw ctx lockingPavel Begunkov
We can run normal task_work without locking the ctx, however we try to lock anyway and most handlers prefer or require it locked. It might have been interesting to multi-submitter ring with high contention completing async read/write requests via task_work, however that will still need to go through io_req_complete_post() and potentially take the lock for rsrc node putting or some other case. In other words, it's hard to care about it, so alawys force the locking. The case described would also because of various io_uring caches. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/6ae858f2ef562e6ed9f13c60978c0d48926954ba.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/rw: avoid punting to io-wq directlyPavel Begunkov
kiocb_done() should care to specifically redirecting requests to io-wq. Remove the hopping to tw to then queue an io-wq, return -EAGAIN and let the core code io_uring handle offloading. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/413564e550fe23744a970e1783dfa566291b0e6f.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring/cmd: move io_uring_try_cancel_uring_cmd()Pavel Begunkov
io_uring_try_cancel_uring_cmd() is a part of the cmd handling so let's move it closer to all cmd bits into uring_cmd.c Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/43a3937af4933655f0fd9362c381802f804f43de.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-07fs: claw back a few FMODE_* bitsChristian Brauner
There's a bunch of flags that are purely based on what the file operations support while also never being conditionally set or unset. IOW, they're not subject to change for individual files. Imho, such flags don't need to live in f_mode they might as well live in the fops structs itself. And the fops struct already has that lonely mmap_supported_flags member. We might as well turn that into a generic fop_flags member and move a few flags from FMODE_* space into FOP_* space. That gets us four FMODE_* bits back and the ability for new static flags that are about file ops to not have to live in FMODE_* space but in their own FOP_* space. It's not the most beautiful thing ever but it gets the job done. Yes, there'll be an additional pointer chase but hopefully that won't matter for these flags. I suspect there's a few more we can move into there and that we can also redirect a bunch of new flag suggestions that follow this pattern into the fop_flags field instead of f_mode. Link: https://lore.kernel.org/r/20240328-gewendet-spargel-aa60a030ef74@brauner Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-04-05io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failureAlexey Izbyshev
This bug was introduced in commit 950e79dd7313 ("io_uring: minor io_cqring_wait() optimization"), which was made in preparation for adc8682ec690 ("io_uring: Add support for napi_busy_poll"). The latter got reverted in cb3182167325 ("Revert "io_uring: Add support for napi_busy_poll""), so simply undo the former as well. Cc: stable@vger.kernel.org Fixes: 950e79dd7313 ("io_uring: minor io_cqring_wait() optimization") Signed-off-by: Alexey Izbyshev <izbyshev@ispras.ru> Link: https://lore.kernel.org/r/20240405125551.237142-1-izbyshev@ispras.ru Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-02io_uring/kbuf: hold io_buffer_list reference over mmapJens Axboe
If we look up the kbuf, ensure that it doesn't get unregistered until after we're done with it. Since we're inside mmap, we cannot safely use the io_uring lock. Rely on the fact that we can lookup the buffer list under RCU now and grab a reference to it, preventing it from being unregistered until we're done with it. The lookup returns the io_buffer_list directly with it referenced. Cc: stable@vger.kernel.org # v6.4+ Fixes: 5cf4f52e6d8a ("io_uring: free io_buffer_list entries via RCU") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-02io_uring/kbuf: get rid of lower BGID listsJens Axboe
Just rely on the xarray for any kind of bgid. This simplifies things, and it really doesn't bring us much, if anything. Cc: stable@vger.kernel.org # v6.4+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-02io_uring: use private workqueue for exit workJens Axboe
Rather than use the system unbound event workqueue, use an io_uring specific one. This avoids dependencies with the tty, which also uses the system_unbound_wq, and issues flushes of said workqueue from inside its poll handling. Cc: stable@vger.kernel.org Reported-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com> Tested-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com> Tested-by: Iskren Chernev <me@iskren.info> Link: https://github.com/axboe/liburing/issues/1113 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-01io_uring: disable io-wq execution of multishot NOWAIT requestsJens Axboe
Do the same check for direct io-wq execution for multishot requests that commit 2a975d426c82 did for the inline execution, and disable multishot mode (and revert to single shot) if the file type doesn't support NOWAIT, and isn't opened in O_NONBLOCK mode. For multishot to work properly, it's a requirement that nonblocking read attempts can be done. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-16io_uring: clear opcode specific data for an early failureJens Axboe
If failure happens before the opcode prep handler is called, ensure that we clear the opcode specific area of the request, which holds data specific to that request type. This prevents errors where opcode handlers either don't get to clear per-request private data since prep isn't even called. Reported-and-tested-by: syzbot+f8e9a371388aa62ecab4@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-13io_uring: Fix release of pinned pages when __io_uaddr_map failsGabriel Krisman Bertazi
Looking at the error path of __io_uaddr_map, if we fail after pinning the pages for any reasons, ret will be set to -EINVAL and the error handler won't properly release the pinned pages. I didn't manage to trigger it without forcing a failure, but it can happen in real life when memory is heavily fragmented. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Fixes: 223ef4743164 ("io_uring: don't allow IORING_SETUP_NO_MMAP rings on highmem pages") Link: https://lore.kernel.org/r/20240313213912.1920-1-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-13io_uring: simplify io_pages_freePavel Begunkov
We never pass a null (top-level) pointer, remove the check. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0e1a46f9a5cd38e6876905e8030bdff9b0845e96.1710343154.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-12io_uring: clean rings on NO_MMAP alloc failPavel Begunkov
We make a few cancellation judgements based on ctx->rings, so let's zero it afer deallocation for IORING_SETUP_NO_MMAP just like it's done with the mmap case. Likely, it's not a real problem, but zeroing is safer and better tested. Cc: stable@vger.kernel.org Fixes: 03d89a2de25bbc ("io_uring: support for user allocated memory for rings/sqes") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9ff6cdf91429b8a51699c210e1f6af6ea3f8bdcf.1710255382.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-11io_uring: don't save/restore iowait stateJens Axboe
This kind of state is per-syscall, and since we're doing the waiting off entering the io_uring_enter(2) syscall, there's no way that iowait can already be set for this case. Simplify it by setting it if we need to, and always clearing it to 0 when done. Fixes: 7b72d661f1f2 ("io_uring: gate iowait schedule on having pending requests") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-08io_uring: refactor DEFER_TASKRUN multishot checksPavel Begunkov
We disallow DEFER_TASKRUN multishots from running by io-wq, which is checked by individual opcodes in the issue path. We can consolidate all it in io_wq_submit_work() at the same time moving the checks out of the hot path. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/e492f0f11588bb5aa11d7d24e6f53b7c7628afdb.1709905727.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-15io_uring: kill stale comment for io_cqring_overflow_kill()Jens Axboe
This function now deals only with discarding overflow entries on ring free and exit, and it no longer returns whether we successfully flushed all entries as there's no CQE posting involved anymore. Kill the outdated comment. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-14io_uring: wake SQPOLL task when task_work is added to an empty queueJens Axboe
If there's no current work on the list, we still need to potentially wake the SQPOLL task if it is sleeping. This is ordered with the wait queue addition in sqpoll, which adds to the wait queue before checking for pending work items. Fixes: af5d68f8892f ("io_uring/sqpoll: manage task_work privately") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-14io_uring/napi: ensure napi polling is aborted when work is availableJens Axboe
While testing io_uring NAPI with DEFER_TASKRUN, I ran into slowdowns and stalls in packet delivery. Turns out that while io_napi_busy_loop_should_end() aborts appropriately on regular task_work, it does not abort if we have local task_work pending. Move io_has_work() into the private io_uring.h header, and gate whether we should continue polling on that as well. This makes NAPI polling on send/receive work as designed with IORING_SETUP_DEFER_TASKRUN as well. Fixes: 8d0c12a80cde ("io-uring: add napi busy poll support") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-12io_uring: Don't include af_unix.h.Kuniyuki Iwashima
Changes to AF_UNIX trigger rebuild of io_uring, but io_uring does not use AF_UNIX anymore. Let's not include af_unix.h and instead include necessary headers. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240212234236.63714-1-kuniyu@amazon.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-09io-uring: add napi busy poll supportStefan Roesch
This adds the napi busy polling support in io_uring.c. It adds a new napi_list to the io_ring_ctx structure. This list contains the list of napi_id's that are currently enabled for busy polling. The list is synchronized by the new napi_lock spin lock. The current default napi busy polling time is stored in napi_busy_poll_to. If napi busy polling is not enabled, the value is 0. In addition there is also a hash table. The hash table store the napi id and the pointer to the above list nodes. The hash table is used to speed up the lookup to the list elements. The hash table is synchronized with rcu. The NAPI_TIMEOUT is stored as a timeout to make sure that the time a napi entry is stored in the napi list is limited. The busy poll timeout is also stored as part of the io_wait_queue. This is necessary as for sq polling the poll interval needs to be adjusted and the napi callback allows only to pass in one value. This has been tested with two simple programs from the liburing library repository: the napi client and the napi server program. The client sends a request, which has a timestamp in its payload and the server replies with the same payload. The client calculates the roundtrip time and stores it to calculate the results. The client is running on host1 and the server is running on host 2 (in the same rack). The measured times below are roundtrip times. They are average times over 5 runs each. Each run measures 1 million roundtrips. no rx coal rx coal: frames=88,usecs=33 Default 57us 56us client_poll=100us 47us 46us server_poll=100us 51us 46us client_poll=100us+ 40us 40us server_poll=100us client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on client client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on server client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on client + server Signed-off-by: Stefan Roesch <shr@devkernel.io> Suggested-by: Olivier Langlois <olivier@trillion01.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230608163839.2891748-5-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-09io-uring: move io_wait_queue definition to header fileStefan Roesch
This moves the definition of the io_wait_queue structure to the header file so it can be also used from other files. Signed-off-by: Stefan Roesch <shr@devkernel.io> Link: https://lore.kernel.org/r/20230608163839.2891748-4-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: Simplify the allocation of slab cachesKunwu Chan
commit 0a31bd5f2bbb ("KMEM_CACHE(): simplify slab cache creation") introduces a new macro. Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Link: https://lore.kernel.org/r/20240130100247.81460-1-chentao@kylinos.cn Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring/sqpoll: manage task_work privatelyJens Axboe
Decouple from task_work running, and cap the number of entries we process at the time. If we exceed that number, push remaining entries to a retry list that we'll process first next time. We cap the number of entries to process at 8, which is fairly random. We just want to get enough per-ctx batching here, while not processing endlessly. Since we manually run PF_IO_WORKER related task_work anyway as the task never exits to userspace, with this we no longer need to add an actual task_work item to the per-process list. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: pass in counter to handle_tw_list() rather than return itJens Axboe
No functional changes in this patch, just in preparation for returning something other than count from this helper. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: cleanup handle_tw_list() calling conventionJens Axboe
Now that we don't loop around task_work anymore, there's no point in maintaining the ring and locked state outside of handle_tw_list(). Get rid of passing in those pointers (and pointers to pointers) and just do the management internally in handle_tw_list(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove unconditional looping in local task_work handlingJens Axboe
If we have a ton of notifications coming in, we can be looping in here for a long time. This can be problematic for various reasons, mostly because we can starve userspace. If the application is waiting on N events, then only re-run if we need more events. Fixes: c0e0d6ba25f1 ("io_uring: add IORING_SETUP_DEFER_TASKRUN") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove next io_kiocb fetch in task_work runningJens Axboe
We just reversed the task_work list and that will have touched requests as well, just get rid of this optimization as it should not make a difference anymore. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: handle traditional task_work in FIFO orderJens Axboe
For local task_work, which is used if IORING_SETUP_DEFER_TASKRUN is set, we reverse the order of the lockless list before processing the work. This is done to process items in the order in which they were queued, as the llist always adds to the head. Do the same for traditional task_work, so we have the same behavior for both types. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove 'loops' argument from trace_io_uring_task_work_run()Jens Axboe
We no longer loop in task_work handling, hence delete the argument from the tracepoint as it's always 1 and hence not very informative. Signed-off-by: Jens Axboe <axboe@kernel.dk>