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io_uring: remove dependency on ring->sq/cq_entries

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We have numbers of {sq,cq} entries cached in ctx, don't look up them in
user-shared rings as 1) it may fetch additional cacheline 2) user may
change it and so it's always error prone.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/745d31bc2da41283ddd0489ef784af5c8d6310e9.1621201931.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-05-16 22:58:08 +01:00 committed by Jens Axboe
parent b13a8918d3
commit a566c5562d
1 changed files with 3 additions and 4 deletions
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7
fs/io_uring.c
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@ -1356,7 +1356,7 @@ static inline bool io_sqring_full(struct io_ring_ctx *ctx)
{
struct io_rings *r = ctx->rings;
return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;
return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
}
static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
@ -1374,7 +1374,7 @@ static inline struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
* control dependency is enough as we're using WRITE_ONCE to
* fill the cq entry
*/
if (__io_cqring_events(ctx) == rings->cq_ring_entries)
if (__io_cqring_events(ctx) == ctx->cq_entries)
return NULL;
tail = ctx->cached_cq_tail++;
@ -1427,11 +1427,10 @@ static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
/* Returns true if there are no backlogged entries after the flush */
static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
{
struct io_rings *rings = ctx->rings;
unsigned long flags;
bool all_flushed, posted;
if (!force && __io_cqring_events(ctx) == rings->cq_ring_entries)
if (!force && __io_cqring_events(ctx) == ctx->cq_entries)
return false;
posted = false;