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io_uring: further deduplicate #CQ events calc

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Apparently, there is one more place hand coded calculation of number of
CQ events in the ring. Use __io_cqring_events() helper in
io_get_cqring() as well. Naturally, assembly stays identical.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov
2021-01-19 13:32:39 +00:00
committed by Jens Axboe
parent ec30e04ba4
commit 888aae2eed
1 changed files with 7 additions and 8 deletions
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15
fs/io_uring.c
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@@ -1700,21 +1700,25 @@ static inline bool io_sqring_full(struct io_ring_ctx *ctx)
return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;
}
static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
{
return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
}
static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
{
struct io_rings *rings = ctx->rings;
unsigned tail;
tail = ctx->cached_cq_tail;
/*
* writes to the cq entry need to come after reading head; the
* control dependency is enough as we're using WRITE_ONCE to
* fill the cq entry
*/
if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
if (__io_cqring_events(ctx) == rings->cq_ring_entries)
return NULL;
ctx->cached_cq_tail++;
tail = ctx->cached_cq_tail++;
return &rings->cqes[tail & ctx->cq_mask];
}
@@ -1729,11 +1733,6 @@ static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
return io_wq_current_is_worker();
}
static inline unsigned __io_cqring_events(struct io_ring_ctx *ctx)
{
return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
}
static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
{
/* see waitqueue_active() comment */