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io_uring/napi: Use lock guards

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Convert napi locks to use the shiny new Scope-Based Resource Management
machinery.

Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Link: https://lore.kernel.org/r/2680ca47ee183cfdb89d1a40c84d349edeb620ab.1728828877.git.olivier@trillion01.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Olivier Langlois 2024-10-13 14:29:02 -04:00 committed by Jens Axboe
parent a5e26f49fe
commit db1e1adf6f
1 changed files with 21 additions and 19 deletions
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40
io_uring/napi.c
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@ -49,14 +49,13 @@ int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id)
hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))];
rcu_read_lock();
e = io_napi_hash_find(hash_list, napi_id);
if (e) {
WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT);
rcu_read_unlock();
return -EEXIST;
scoped_guard(rcu) {
e = io_napi_hash_find(hash_list, napi_id);
if (e) {
WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT);
return -EEXIST;
}
}
rcu_read_unlock();
e = kmalloc(sizeof(*e), GFP_NOWAIT);
if (!e)
@ -65,6 +64,10 @@ int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id)
e->napi_id = napi_id;
e->timeout = jiffies + NAPI_TIMEOUT;
/*
* guard(spinlock) is not used to manually unlock it before calling
* kfree()
*/
spin_lock(&ctx->napi_lock);
if (unlikely(io_napi_hash_find(hash_list, napi_id))) {
spin_unlock(&ctx->napi_lock);
@ -82,7 +85,7 @@ static void __io_napi_remove_stale(struct io_ring_ctx *ctx)
{
struct io_napi_entry *e;
spin_lock(&ctx->napi_lock);
guard(spinlock)(&ctx->napi_lock);
/*
* list_for_each_entry_safe() is not required as long as:
* 1. list_del_rcu() does not reset the deleted node next pointer
@ -96,7 +99,6 @@ static void __io_napi_remove_stale(struct io_ring_ctx *ctx)
kfree_rcu(e, rcu);
}
}
spin_unlock(&ctx->napi_lock);
}
static inline void io_napi_remove_stale(struct io_ring_ctx *ctx, bool is_stale)
@ -168,11 +170,12 @@ static void io_napi_blocking_busy_loop(struct io_ring_ctx *ctx,
if (list_is_singular(&ctx->napi_list))
loop_end_arg = iowq;
rcu_read_lock();
do {
is_stale = __io_napi_do_busy_loop(ctx, loop_end_arg);
} while (!io_napi_busy_loop_should_end(iowq, start_time) && !loop_end_arg);
rcu_read_unlock();
scoped_guard(rcu) {
do {
is_stale = __io_napi_do_busy_loop(ctx, loop_end_arg);
} while (!io_napi_busy_loop_should_end(iowq, start_time) &&
!loop_end_arg);
}
io_napi_remove_stale(ctx, is_stale);
}
@ -203,13 +206,12 @@ void io_napi_free(struct io_ring_ctx *ctx)
{
struct io_napi_entry *e;
spin_lock(&ctx->napi_lock);
guard(spinlock)(&ctx->napi_lock);
list_for_each_entry(e, &ctx->napi_list, list) {
hash_del_rcu(&e->node);
kfree_rcu(e, rcu);
}
INIT_LIST_HEAD_RCU(&ctx->napi_list);
spin_unlock(&ctx->napi_lock);
}
/*
@ -305,9 +307,9 @@ int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx)
if (list_empty_careful(&ctx->napi_list))
return 0;
rcu_read_lock();
is_stale = __io_napi_do_busy_loop(ctx, NULL);
rcu_read_unlock();
scoped_guard(rcu) {
is_stale = __io_napi_do_busy_loop(ctx, NULL);
}
io_napi_remove_stale(ctx, is_stale);
return 1;