io_uring/poll: get rid of per-hashtable bucket locks

Any access to the table is protected by ctx->uring_lock now anyway, the
per-bucket locking doesn't buy us anything.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index d8ca27da13416c3370f572b21c41954fb7175fd9..9c7e1d3f06e5230b323062e598ea9f981bdb4058 100644 (file)
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -67,7 +67,6 @@ struct io_file_table {
 };
 
 struct io_hash_bucket {
-       spinlock_t              lock;
        struct hlist_head       list;
 } ____cacheline_aligned_in_smp;
 

diff --git a/io_uring/cancel.c b/io_uring/cancel.c
index a6e58a20efdd277e742c40a04eb948698dd8e563..755dd5506a5fa06b8f79c6b89043a71bec17abb9 100644 (file)
--- a/io_uring/cancel.c
+++ b/io_uring/cancel.c
@@ -236,10 +236,8 @@ void init_hash_table(struct io_hash_table *table, unsigned size)
 {
        unsigned int i;
 
-       for (i = 0; i < size; i++) {
-               spin_lock_init(&table->hbs[i].lock);
+       for (i = 0; i < size; i++)
                INIT_HLIST_HEAD(&table->hbs[i].list);
-       }
 }
 
 static int __io_sync_cancel(struct io_uring_task *tctx,

diff --git a/io_uring/poll.c b/io_uring/poll.c
index a0d1a09c5a202dcd843f1de84f5ec73dd2a7b0cd..2d6698fb740008e443a303c55f2584a345b59eaf 100644 (file)
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -728,7 +728,6 @@ __cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
        for (i = 0; i < nr_buckets; i++) {
                struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
 
-               spin_lock(&hb->lock);
                hlist_for_each_entry_safe(req, tmp, &hb->list, hash_node) {
                        if (io_match_task_safe(req, tsk, cancel_all)) {
                                hlist_del_init(&req->hash_node);
@@ -736,22 +735,17 @@ __cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
                                found = true;
                        }
                }
-               spin_unlock(&hb->lock);
        }
        return found;
 }
 
 static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only,
-                                    struct io_cancel_data *cd,
-                                    struct io_hash_bucket **out_bucket)
+                                    struct io_cancel_data *cd)
 {
        struct io_kiocb *req;
        u32 index = hash_long(cd->data, ctx->cancel_table.hash_bits);
        struct io_hash_bucket *hb = &ctx->cancel_table.hbs[index];
 
-       *out_bucket = NULL;
-
-       spin_lock(&hb->lock);
        hlist_for_each_entry(req, &hb->list, hash_node) {
                if (cd->data != req->cqe.user_data)
                        continue;
@@ -761,34 +755,25 @@ static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only,
                        if (io_cancel_match_sequence(req, cd->seq))
                                continue;
                }
-               *out_bucket = hb;
                return req;
        }
-       spin_unlock(&hb->lock);
        return NULL;
 }
 
 static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx,
-                                         struct io_cancel_data *cd,
-                                         struct io_hash_bucket **out_bucket)
+                                         struct io_cancel_data *cd)
 {
        unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits;
        struct io_kiocb *req;
        int i;
 
-       *out_bucket = NULL;
-
        for (i = 0; i < nr_buckets; i++) {
                struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
 
-               spin_lock(&hb->lock);
                hlist_for_each_entry(req, &hb->list, hash_node) {
-                       if (io_cancel_req_match(req, cd)) {
-                               *out_bucket = hb;
+                       if (io_cancel_req_match(req, cd))
                                return req;
-                       }
                }
-               spin_unlock(&hb->lock);
        }
        return NULL;
 }
@@ -806,20 +791,19 @@ static int io_poll_disarm(struct io_kiocb *req)
 
 static int __io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
 {
-       struct io_hash_bucket *bucket;
        struct io_kiocb *req;
 
        if (cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP |
                         IORING_ASYNC_CANCEL_ANY))
-               req = io_poll_file_find(ctx, cd, &bucket);
+               req = io_poll_file_find(ctx, cd);
        else
-               req = io_poll_find(ctx, false, cd, &bucket);
+               req = io_poll_find(ctx, false, cd);
 
-       if (req)
+       if (req) {
                io_poll_cancel_req(req);
-       if (bucket)
-               spin_unlock(&bucket->lock);
-       return req ? 0 : -ENOENT;
+               return 0;
+       }
+       return -ENOENT;
 }
 
 int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
@@ -918,15 +902,12 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)
        struct io_poll_update *poll_update = io_kiocb_to_cmd(req, struct io_poll_update);
        struct io_ring_ctx *ctx = req->ctx;
        struct io_cancel_data cd = { .ctx = ctx, .data = poll_update->old_user_data, };
-       struct io_hash_bucket *bucket;
        struct io_kiocb *preq;
        int ret2, ret = 0;
 
        io_ring_submit_lock(ctx, issue_flags);
-       preq = io_poll_find(ctx, true, &cd, &bucket);
+       preq = io_poll_find(ctx, true, &cd);
        ret2 = io_poll_disarm(preq);
-       if (bucket)
-               spin_unlock(&bucket->lock);
        if (ret2) {
                ret = ret2;
                goto out;