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The recent Linux io_uring API has several advantages over ppoll(2) and epoll(2). Details are given in the source code. Add an io_uring implementation and make it the default on Linux. Performance is the same as with epoll(7) but later patches add optimizations that take advantage of io_uring. It is necessary to change how aio_set_fd_handler() deals with deleting AioHandlers since removing monitored file descriptors is asynchronous in io_uring. fdmon_io_uring_remove() marks the AioHandler deleted and aio_set_fd_handler() will let it handle deletion in that case. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-6-stefanha@redhat.com Message-Id: <20200305170806.1313245-6-stefanha@redhat.com>
80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
/*
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* AioContext POSIX event loop implementation internal APIs
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*
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* Copyright IBM, Corp. 2008
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* Copyright Red Hat, Inc. 2020
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#ifndef AIO_POSIX_H
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#define AIO_POSIX_H
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#include "block/aio.h"
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struct AioHandler {
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GPollFD pfd;
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IOHandler *io_read;
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IOHandler *io_write;
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AioPollFn *io_poll;
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IOHandler *io_poll_begin;
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IOHandler *io_poll_end;
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void *opaque;
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QLIST_ENTRY(AioHandler) node;
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QLIST_ENTRY(AioHandler) node_ready; /* only used during aio_poll() */
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QLIST_ENTRY(AioHandler) node_deleted;
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#ifdef CONFIG_LINUX_IO_URING
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QSLIST_ENTRY(AioHandler) node_submitted;
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unsigned flags; /* see fdmon-io_uring.c */
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#endif
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bool is_external;
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};
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/* Add a handler to a ready list */
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void aio_add_ready_handler(AioHandlerList *ready_list, AioHandler *node,
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int revents);
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extern const FDMonOps fdmon_poll_ops;
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#ifdef CONFIG_EPOLL_CREATE1
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bool fdmon_epoll_try_upgrade(AioContext *ctx, unsigned npfd);
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void fdmon_epoll_setup(AioContext *ctx);
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void fdmon_epoll_disable(AioContext *ctx);
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#else
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static inline bool fdmon_epoll_try_upgrade(AioContext *ctx, unsigned npfd)
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{
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return false;
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}
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static inline void fdmon_epoll_setup(AioContext *ctx)
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{
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}
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static inline void fdmon_epoll_disable(AioContext *ctx)
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{
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}
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#endif /* !CONFIG_EPOLL_CREATE1 */
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#ifdef CONFIG_LINUX_IO_URING
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bool fdmon_io_uring_setup(AioContext *ctx);
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void fdmon_io_uring_destroy(AioContext *ctx);
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#else
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static inline bool fdmon_io_uring_setup(AioContext *ctx)
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{
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return false;
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}
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static inline void fdmon_io_uring_destroy(AioContext *ctx)
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{
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}
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#endif /* !CONFIG_LINUX_IO_URING */
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#endif /* AIO_POSIX_H */
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