eb4a299b2f
kmalloc'ing struct io_notif is too expensive when done frequently, cache them as many other resources in io_uring. Keep two list, the first one is from where we're getting notifiers, it's protected by ->uring_lock. The second is protected by ->completion_lock, to which we queue released notifiers. Then we splice one list into another when needed. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9dec18f7fcbab9f4bd40b96e5ae158b119945230.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
70 lines
1.7 KiB
C
70 lines
1.7 KiB
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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#define IO_NOTIF_SPLICE_BATCH 32
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struct io_notif {
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struct ubuf_info uarg;
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struct io_ring_ctx *ctx;
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/* cqe->user_data, io_notif_slot::tag if not overridden */
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u64 tag;
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/* see struct io_notif_slot::seq */
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u32 seq;
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/* hook into ctx->notif_list and ctx->notif_list_locked */
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struct list_head cache_node;
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union {
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struct callback_head task_work;
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struct work_struct commit_work;
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};
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};
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struct io_notif_slot {
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/*
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* Current/active notifier. A slot holds only one active notifier at a
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* time and keeps one reference to it. Flush releases the reference and
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* lazily replaces it with a new notifier.
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*/
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struct io_notif *notif;
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/*
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* Default ->user_data for this slot notifiers CQEs
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*/
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u64 tag;
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/*
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* Notifiers of a slot live in generations, we create a new notifier
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* only after flushing the previous one. Track the sequential number
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* for all notifiers and copy it into notifiers's cqe->cflags
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*/
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u32 seq;
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};
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int io_notif_unregister(struct io_ring_ctx *ctx);
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void io_notif_cache_purge(struct io_ring_ctx *ctx);
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struct io_notif *io_alloc_notif(struct io_ring_ctx *ctx,
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struct io_notif_slot *slot);
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static inline struct io_notif *io_get_notif(struct io_ring_ctx *ctx,
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struct io_notif_slot *slot)
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{
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if (!slot->notif)
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slot->notif = io_alloc_notif(ctx, slot);
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return slot->notif;
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}
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static inline struct io_notif_slot *io_get_notif_slot(struct io_ring_ctx *ctx,
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int idx)
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__must_hold(&ctx->uring_lock)
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{
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if (idx >= ctx->nr_notif_slots)
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return NULL;
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idx = array_index_nospec(idx, ctx->nr_notif_slots);
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return &ctx->notif_slots[idx];
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}
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