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

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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>
This commit is contained in:
Jens Axboe 2024-09-30 14:29:06 -06:00
parent 879ba46a38
commit ba4366f57b
3 changed files with 11 additions and 33 deletions
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1
include/linux/io_uring_types.h
View File

@ -67,7 +67,6 @@ struct io_file_table {
}; };
struct io_hash_bucket { struct io_hash_bucket {
spinlock_t lock;
struct hlist_head list; struct hlist_head list;
} ____cacheline_aligned_in_smp; } ____cacheline_aligned_in_smp;

4
io_uring/cancel.c
View File

@ -236,10 +236,8 @@ void init_hash_table(struct io_hash_table *table, unsigned size)
{ {
unsigned int i; unsigned int i;
for (i = 0; i < size; i++) { for (i = 0; i < size; i++)
spin_lock_init(&table->hbs[i].lock);
INIT_HLIST_HEAD(&table->hbs[i].list); INIT_HLIST_HEAD(&table->hbs[i].list);
}
} }
static int __io_sync_cancel(struct io_uring_task *tctx, static int __io_sync_cancel(struct io_uring_task *tctx,

39
io_uring/poll.c
View File

@ -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++) { for (i = 0; i < nr_buckets; i++) {
struct io_hash_bucket *hb = &ctx->cancel_table.hbs[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) { hlist_for_each_entry_safe(req, tmp, &hb->list, hash_node) {
if (io_match_task_safe(req, tsk, cancel_all)) { if (io_match_task_safe(req, tsk, cancel_all)) {
hlist_del_init(&req->hash_node); 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; found = true;
} }
} }
spin_unlock(&hb->lock);
} }
return found; return found;
} }
static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only, static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only,
struct io_cancel_data *cd, struct io_cancel_data *cd)
struct io_hash_bucket **out_bucket)
{ {
struct io_kiocb *req; struct io_kiocb *req;
u32 index = hash_long(cd->data, ctx->cancel_table.hash_bits); u32 index = hash_long(cd->data, ctx->cancel_table.hash_bits);
struct io_hash_bucket *hb = &ctx->cancel_table.hbs[index]; 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) { hlist_for_each_entry(req, &hb->list, hash_node) {
if (cd->data != req->cqe.user_data) if (cd->data != req->cqe.user_data)
continue; 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)) if (io_cancel_match_sequence(req, cd->seq))
continue; continue;
} }
*out_bucket = hb;
return req; return req;
} }
spin_unlock(&hb->lock);
return NULL; return NULL;
} }
static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx, static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx,
struct io_cancel_data *cd, struct io_cancel_data *cd)
struct io_hash_bucket **out_bucket)
{ {
unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits; unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits;
struct io_kiocb *req; struct io_kiocb *req;
int i; int i;
*out_bucket = NULL;
for (i = 0; i < nr_buckets; i++) { for (i = 0; i < nr_buckets; i++) {
struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i]; struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
spin_lock(&hb->lock);
hlist_for_each_entry(req, &hb->list, hash_node) { hlist_for_each_entry(req, &hb->list, hash_node) {
if (io_cancel_req_match(req, cd)) { if (io_cancel_req_match(req, cd))
*out_bucket = hb;
return req; return req;
}
} }
spin_unlock(&hb->lock);
} }
return NULL; 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) static int __io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
{ {
struct io_hash_bucket *bucket;
struct io_kiocb *req; struct io_kiocb *req;
if (cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP | if (cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP |
IORING_ASYNC_CANCEL_ANY)) IORING_ASYNC_CANCEL_ANY))
req = io_poll_file_find(ctx, cd, &bucket); req = io_poll_file_find(ctx, cd);
else 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); io_poll_cancel_req(req);
if (bucket) return 0;
spin_unlock(&bucket->lock); }
return req ? 0 : -ENOENT; return -ENOENT;
} }
int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, 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_poll_update *poll_update = io_kiocb_to_cmd(req, struct io_poll_update);
struct io_ring_ctx *ctx = req->ctx; struct io_ring_ctx *ctx = req->ctx;
struct io_cancel_data cd = { .ctx = ctx, .data = poll_update->old_user_data, }; struct io_cancel_data cd = { .ctx = ctx, .data = poll_update->old_user_data, };
struct io_hash_bucket *bucket;
struct io_kiocb *preq; struct io_kiocb *preq;
int ret2, ret = 0; int ret2, ret = 0;
io_ring_submit_lock(ctx, issue_flags); 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); ret2 = io_poll_disarm(preq);
if (bucket)
spin_unlock(&bucket->lock);
if (ret2) { if (ret2) {
ret = ret2; ret = ret2;
goto out; goto out;