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| author | Pavel Begunkov <asml.silence@gmail.com> | 2023-04-04 14:39:45 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-04-04 17:30:39 +0200 |
| commit | b8fb5b4fdd67f9d18109c5d21d44a8bd4ddb608b (patch) | |
| tree | d88a6c8049aeb16442461afa53182a2c603a5eb6 /io_uring/rsrc.h | |
| parent | io_uring: cap io_sqring_entries() at SQ ring size (diff) | |
| download | linux-b8fb5b4fdd67f9d18109c5d21d44a8bd4ddb608b.tar.xz linux-b8fb5b4fdd67f9d18109c5d21d44a8bd4ddb608b.zip | |
io_uring/rsrc: use non-pcpu refcounts for nodes
One problem with the current rsrc infra is that often updates will
generates lots of rsrc nodes, each carry pcpu refs. That takes quite a
lot of memory, especially if there is a stall, and takes lots of CPU
cycles. Only pcpu allocations takes >50 of CPU with a naive benchmark
updating files in a loop.
Replace pcpu refs with normal refcounting. There is already a hot path
avoiding atomics / refs, but following patches will further improve it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e9ed8a9457b331a26555ff9443afc64cdaab7247.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/rsrc.h')
| -rw-r--r-- | io_uring/rsrc.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h index f27f4975217d..1467b31843bc 100644 --- a/io_uring/rsrc.h +++ b/io_uring/rsrc.h @@ -37,7 +37,7 @@ struct io_rsrc_data { }; struct io_rsrc_node { - struct percpu_ref refs; + refcount_t refs; struct list_head node; struct list_head rsrc_list; struct io_rsrc_data *rsrc_data; @@ -54,6 +54,7 @@ struct io_mapped_ubuf { }; void io_rsrc_put_tw(struct callback_head *cb); +void io_rsrc_node_ref_zero(struct io_rsrc_node *node); void io_rsrc_put_work(struct work_struct *work); void io_rsrc_refs_refill(struct io_ring_ctx *ctx); void io_wait_rsrc_data(struct io_rsrc_data *data); @@ -109,7 +110,8 @@ int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, static inline void io_rsrc_put_node(struct io_rsrc_node *node, int nr) { - percpu_ref_put_many(&node->refs, nr); + if (refcount_sub_and_test(nr, &node->refs)) + io_rsrc_node_ref_zero(node); } static inline void io_req_put_rsrc(struct io_kiocb *req) |