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linux/io_uring/rw.h

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io_uring: move read/write related opcodes to its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-13 13:27:03 +00:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/pagemap.h>
struct io_async_rw {
io_uring/alloc_cache: switch to array based caching 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>
2024-03-20 21:19:44 +00:00
size_t bytes_done;
io_uring: get rid of struct io_rw_state A separate state struct is not needed anymore, just fold it in with io_async_rw. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-18 22:25:58 +00:00
struct iov_iter iter;
struct iov_iter_state iter_state;
io_uring/rw: add iovec recycling Let the io_async_rw hold on to the iovec and reuse it, rather than always allocate and free them. Also enables KASAN for the iovec entries, so that reuse can be detected even while they are in the cache. While doing so, shrink io_async_rw by getting rid of the bigger embedded fast iovec. Since iovecs are being recycled now, shrink it from 8 to 1. This reduces the io_async_rw size from 264 to 160 bytes, a 40% reduction. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-18 22:31:44 +00:00
struct iovec fast_iov;
io_uring/rw: always setup io_async_rw for read/write requests 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>
2024-03-18 22:13:01 +00:00
struct iovec *free_iovec;
io_uring/rw: add iovec recycling Let the io_async_rw hold on to the iovec and reuse it, rather than always allocate and free them. Also enables KASAN for the iovec entries, so that reuse can be detected even while they are in the cache. While doing so, shrink io_async_rw by getting rid of the bigger embedded fast iovec. Since iovecs are being recycled now, shrink it from 8 to 1. This reduces the io_async_rw size from 264 to 160 bytes, a 40% reduction. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-18 22:31:44 +00:00
int free_iov_nr;
io_uring: move read/write related opcodes to its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-13 13:27:03 +00:00
struct wait_page_queue wpq;
};
io_uring/rw: always setup io_async_rw for read/write requests 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>
2024-03-18 22:13:01 +00:00
int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe);
io_uring: move read/write related opcodes to its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-13 13:27:03 +00:00
int io_read(struct io_kiocb *req, unsigned int issue_flags);
int io_write(struct io_kiocb *req, unsigned int issue_flags);
void io_readv_writev_cleanup(struct io_kiocb *req);
io_uring/rw: don't lose partial IO result on fail A partially done read/write may end up in io_req_complete_failed() and loose the result, make sure we return the number of bytes processed. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/05e0879c226bcd53b441bf92868eadd4bf04e2fc.1663668091.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 11:17:47 +00:00
void io_rw_fail(struct io_kiocb *req);
io_uring: avoid indirect function calls for the hottest task_work We use task_work for a variety of reasons, but doing completions or triggering rety after poll are by far the hottest two. Use the indirect funtion call wrappers to avoid the indirect function call if CONFIG_RETPOLINE is set. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-02 14:41:46 +00:00
void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts);
io_uring/rw: add support for IORING_OP_READ_MULTISHOT This behaves like IORING_OP_READ, except: 1) It only supports pollable files (eg pipes, sockets, etc). Note that for sockets, you probably want to use recv/recvmsg with multishot instead. 2) It supports multishot mode, meaning it will repeatedly trigger a read and fill a buffer when data is available. This allows similar use to recv/recvmsg but on non-sockets, where a single request will repeatedly post a CQE whenever data is read from it. 3) Because of #2, it must be used with provided buffers. This is uniformly true across any request type that supports multishot and transfers data, with the reason being that it's obviously not possible to pass in a single buffer for the data, as multiple reads may very well trigger before an application has a chance to process previous CQEs and the data passed from them. Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-11 19:35:42 +00:00
int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags);
io_uring/alloc_cache: switch to array based caching 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>
2024-03-20 21:19:44 +00:00
void io_rw_cache_free(const void *entry);
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