Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
io_uring/napi: Use lock guards
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>
authored by
Olivier Langlois
and committed by
Jens Axboe
db1e1adf
a5e26f49
+21
-19
+21
-19
io_uring/napi.c
+21
-19
io_uring/napi.c
···
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hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))];
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-
rcu_read_lock();
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e = io_napi_hash_find(hash_list, napi_id);
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if (e) {
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WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT);
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rcu_read_unlock();
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return -EEXIST;
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+
scoped_guard(rcu) {
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e = io_napi_hash_find(hash_list, napi_id);
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if (e) {
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WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT);
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return -EEXIST;
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}
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}
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-
rcu_read_unlock();
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e = kmalloc(sizeof(*e), GFP_NOWAIT);
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if (!e)
···
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e->napi_id = napi_id;
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e->timeout = jiffies + NAPI_TIMEOUT;
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/*
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* guard(spinlock) is not used to manually unlock it before calling
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* kfree()
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*/
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spin_lock(&ctx->napi_lock);
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if (unlikely(io_napi_hash_find(hash_list, napi_id))) {
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spin_unlock(&ctx->napi_lock);
···
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{
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struct io_napi_entry *e;
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spin_lock(&ctx->napi_lock);
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guard(spinlock)(&ctx->napi_lock);
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/*
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* list_for_each_entry_safe() is not required as long as:
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* 1. list_del_rcu() does not reset the deleted node next pointer
···
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kfree_rcu(e, rcu);
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}
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}
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spin_unlock(&ctx->napi_lock);
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}
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static inline void io_napi_remove_stale(struct io_ring_ctx *ctx, bool is_stale)
···
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if (list_is_singular(&ctx->napi_list))
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loop_end_arg = iowq;
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rcu_read_lock();
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do {
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is_stale = __io_napi_do_busy_loop(ctx, loop_end_arg);
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} while (!io_napi_busy_loop_should_end(iowq, start_time) && !loop_end_arg);
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rcu_read_unlock();
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scoped_guard(rcu) {
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do {
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is_stale = __io_napi_do_busy_loop(ctx, loop_end_arg);
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} while (!io_napi_busy_loop_should_end(iowq, start_time) &&
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!loop_end_arg);
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}
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io_napi_remove_stale(ctx, is_stale);
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}
···
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{
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struct io_napi_entry *e;
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-
spin_lock(&ctx->napi_lock);
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guard(spinlock)(&ctx->napi_lock);
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list_for_each_entry(e, &ctx->napi_list, list) {
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hash_del_rcu(&e->node);
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kfree_rcu(e, rcu);
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}
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INIT_LIST_HEAD_RCU(&ctx->napi_list);
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spin_unlock(&ctx->napi_lock);
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}
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/*
···
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if (list_empty_careful(&ctx->napi_list))
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return 0;
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-
rcu_read_lock();
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is_stale = __io_napi_do_busy_loop(ctx, NULL);
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rcu_read_unlock();
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scoped_guard(rcu) {
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is_stale = __io_napi_do_busy_loop(ctx, NULL);
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}
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io_napi_remove_stale(ctx, is_stale);
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return 1;