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3a6ee45e3c
commit e307e66981 upstream.
It might be useful for applications to detect if a zero copy transfer with
SEND[MSG]_ZC was actually possible or not. The application can fallback to
plain SEND[MSG] in order to avoid the overhead of two cqes per request. Or
it can generate a log message that could indicate to an administrator that
no zero copy was possible and could explain degraded performance.
Cc: stable@vger.kernel.org # 6.1
Link: https://lore.kernel.org/io-uring/fb6a7599-8a9b-15e5-9b64-6cd9d01c6ff4@gmail.com/T/#m2b0d9df94ce43b0e69e6c089bdff0ce6babbdfaa
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8945b01756d902f5d5b0667f20b957ad3f742e5e.1666895626.git.metze@samba.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
44 lines
951 B
C
44 lines
951 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/net.h>
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#include <linux/uio.h>
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#include <net/sock.h>
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#include <linux/nospec.h>
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#include "rsrc.h"
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#define IO_NOTIF_SPLICE_BATCH 32
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struct io_notif_data {
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struct file *file;
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struct ubuf_info uarg;
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unsigned long account_pages;
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bool zc_report;
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bool zc_used;
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bool zc_copied;
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};
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void io_notif_flush(struct io_kiocb *notif);
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struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx);
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static inline struct io_notif_data *io_notif_to_data(struct io_kiocb *notif)
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{
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return io_kiocb_to_cmd(notif, struct io_notif_data);
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}
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static inline int io_notif_account_mem(struct io_kiocb *notif, unsigned len)
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{
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struct io_ring_ctx *ctx = notif->ctx;
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struct io_notif_data *nd = io_notif_to_data(notif);
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unsigned nr_pages = (len >> PAGE_SHIFT) + 2;
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int ret;
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if (ctx->user) {
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ret = __io_account_mem(ctx->user, nr_pages);
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if (ret)
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return ret;
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nd->account_pages += nr_pages;
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}
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return 0;
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}
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