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| author | Pavel Begunkov <asml.silence@gmail.com> | 2024-04-10 02:26:54 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-04-15 08:10:26 -0600 |
| commit | 8d09a88ef9d3cb7d21d45c39b7b7c31298d23998 (patch) | |
| tree | 17b8ffd1386460decdad9238aa46959e88532e9b | |
| parent | 408024b959275ba52c233c647901cacfc8d5a226 (diff) | |
| download | linux-stable-8d09a88ef9d3cb7d21d45c39b7b7c31298d23998.tar.gz linux-stable-8d09a88ef9d3cb7d21d45c39b7b7c31298d23998.tar.bz2 linux-stable-8d09a88ef9d3cb7d21d45c39b7b7c31298d23998.zip | |
io_uring: always lock __io_cqring_overflow_flush
Conditional locking is never great, in case of
__io_cqring_overflow_flush(), which is a slow path, it's not justified.
Don't handle IOPOLL separately, always grab uring_lock for overflow
flushing.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/162947df299aa12693ac4b305dacedab32ec7976.1712708261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | io_uring/io_uring.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 740bfec10fde..92ac9c0fc597 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -673,6 +673,8 @@ static void io_cqring_overflow_kill(struct io_ring_ctx *ctx) struct io_overflow_cqe *ocqe; LIST_HEAD(list); + lockdep_assert_held(&ctx->uring_lock); + spin_lock(&ctx->completion_lock); list_splice_init(&ctx->cq_overflow_list, &list); clear_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq); @@ -689,6 +691,8 @@ static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx) { size_t cqe_size = sizeof(struct io_uring_cqe); + lockdep_assert_held(&ctx->uring_lock); + if (__io_cqring_events(ctx) == ctx->cq_entries) return; @@ -718,12 +722,9 @@ static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx) static void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx) { - /* iopoll syncs against uring_lock, not completion_lock */ - if (ctx->flags & IORING_SETUP_IOPOLL) - mutex_lock(&ctx->uring_lock); + mutex_lock(&ctx->uring_lock); __io_cqring_overflow_flush(ctx); - if (ctx->flags & IORING_SETUP_IOPOLL) - mutex_unlock(&ctx->uring_lock); + mutex_unlock(&ctx->uring_lock); } /* can be called by any task */ @@ -1522,6 +1523,8 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) unsigned int nr_events = 0; unsigned long check_cq; + lockdep_assert_held(&ctx->uring_lock); + if (!io_allowed_run_tw(ctx)) return -EEXIST; |