Similarly to how we use the state->ios_left to know how many references to get to a file, we can use it to allocate the io_kiocb's we need in bulk.
Signed-off-by: Jens Axboe <[email protected]> --- fs/io_uring.c | 71 +++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 52 insertions(+), 19 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index cd2dfc153338..b5233786b5a8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -127,6 +127,13 @@ struct io_submit_state { struct list_head req_list; unsigned int req_count; + /* + * io_kiocb alloc cache + */ + void *kiocbs[IO_IOPOLL_BATCH]; + unsigned int free_kiocbs; + unsigned int cur_kiocb; + /* * File reference cache */ @@ -196,36 +203,58 @@ static struct io_uring_cqe *io_peek_cqring(struct io_ring_ctx *ctx) return &ring->cqes[tail & ctx->cq_mask]; } -static struct io_kiocb *io_get_kiocb(struct io_ring_ctx *ctx) +static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) +{ + percpu_ref_put_many(&ctx->refs, refs); + + if (waitqueue_active(&ctx->wait)) + wake_up(&ctx->wait); +} + +static struct io_kiocb *io_get_kiocb(struct io_ring_ctx *ctx, + struct io_submit_state *state) { struct io_kiocb *req; if (!percpu_ref_tryget(&ctx->refs)) return NULL; - req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL); - if (!req) - return NULL; - - req->ki_ctx = ctx; - INIT_LIST_HEAD(&req->ki_list); - req->ki_flags = 0; - return req; -} + if (!state) + req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL); + else if (!state->free_kiocbs) { + size_t sz; + int ret; + + sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->kiocbs)); + ret = kmem_cache_alloc_bulk(kiocb_cachep, GFP_KERNEL, sz, + state->kiocbs); + if (ret <= 0) + goto out; + state->free_kiocbs = ret - 1; + state->cur_kiocb = 1; + req = state->kiocbs[0]; + } else { + req = state->kiocbs[state->cur_kiocb]; + state->free_kiocbs--; + state->cur_kiocb++; + } -static void io_ring_drop_ctx_ref(struct io_ring_ctx *ctx, unsigned refs) -{ - percpu_ref_put_many(&ctx->refs, refs); + if (req) { + req->ki_ctx = ctx; + req->ki_flags = 0; + return req; + } - if (waitqueue_active(&ctx->wait)) - wake_up(&ctx->wait); +out: + io_ring_drop_ctx_refs(ctx, 1); + return NULL; } static void io_free_kiocb_many(struct io_ring_ctx *ctx, void **iocbs, int *nr) { if (*nr) { kmem_cache_free_bulk(kiocb_cachep, *nr, iocbs); - io_ring_drop_ctx_ref(ctx, *nr); + io_ring_drop_ctx_refs(ctx, *nr); *nr = 0; } } @@ -233,7 +262,7 @@ static void io_free_kiocb_many(struct io_ring_ctx *ctx, void **iocbs, int *nr) static void io_free_kiocb(struct io_kiocb *iocb) { kmem_cache_free(kiocb_cachep, iocb); - io_ring_drop_ctx_ref(iocb->ki_ctx, 1); + io_ring_drop_ctx_refs(iocb->ki_ctx, 1); } /* @@ -761,7 +790,7 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, if (unlikely(sqe->flags)) return -EINVAL; - req = io_get_kiocb(ctx); + req = io_get_kiocb(ctx, state); if (unlikely(!req)) return -EAGAIN; @@ -828,6 +857,9 @@ static void io_submit_state_end(struct io_submit_state *state) if (!list_empty(&state->req_list)) io_flush_state_reqs(state->ctx, state); io_file_put(state, NULL); + if (state->free_kiocbs) + kmem_cache_free_bulk(kiocb_cachep, state->free_kiocbs, + &state->kiocbs[state->cur_kiocb]); } /* @@ -839,6 +871,7 @@ static void io_submit_state_start(struct io_submit_state *state, state->ctx = ctx; INIT_LIST_HEAD(&state->req_list); state->req_count = 0; + state->free_kiocbs = 0; state->file = NULL; state->ios_left = max_ios; #ifdef CONFIG_BLOCK @@ -1071,7 +1104,7 @@ SYSCALL_DEFINE4(io_uring_enter, unsigned int, fd, u32, to_submit, ret = __io_uring_enter(ctx, to_submit, min_complete, flags); mutex_unlock(&ctx->uring_lock); } - io_ring_drop_ctx_ref(ctx, 1); + io_ring_drop_ctx_refs(ctx, 1); out_fput: fdput(f); return ret; -- 2.17.1
