From: Olivier Langlois <[email protected]>
To: Jens Axboe <[email protected]>,Pavel Begunkov
<[email protected]>,[email protected]
Subject: [PATCH v3 2/3] io_uring/napi: fix io_napi_entry RCU accesses
Date: Wed, 18 Sep 2024 08:59:30 -0400 [thread overview]
Message-ID: <16fd803fb9fff9323a9d01e54a2584366780bbeb.1726589775.git.olivier@trillion01.com> (raw)
In-Reply-To: <[email protected]>
correct 3 RCU structures modifications that were not using the RCU
functions to make their update.
Signed-off-by: Olivier Langlois <[email protected]>
---
io_uring/napi.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/io_uring/napi.c b/io_uring/napi.c
index 1dd2df9da468..6fc127e74f10 100644
--- a/io_uring/napi.c
+++ b/io_uring/napi.c
@@ -81,19 +81,24 @@ void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock)
}
hlist_add_tail_rcu(&e->node, hash_list);
- list_add_tail(&e->list, &ctx->napi_list);
+ list_add_tail_rcu(&e->list, &ctx->napi_list);
spin_unlock(&ctx->napi_lock);
}
static void __io_napi_remove_stale(struct io_ring_ctx *ctx)
{
struct io_napi_entry *e;
- unsigned int i;
spin_lock(&ctx->napi_lock);
- hash_for_each(ctx->napi_ht, i, e, node) {
+ /*
+ * list_for_each_entry_safe() is not required as long as:
+ * 1. list_del_rcu() does not reset the deleted node next pointer
+ * 2. kfree_rcu() delays the memory freeing until the next quiescent
+ * state
+ */
+ list_for_each_entry(e, &ctx->napi_list, list) {
if (time_after(jiffies, READ_ONCE(e->timeout))) {
- list_del(&e->list);
+ list_del_rcu(&e->list);
hash_del_rcu(&e->node);
kfree_rcu(e, rcu);
}
@@ -204,13 +209,13 @@ void io_napi_init(struct io_ring_ctx *ctx)
void io_napi_free(struct io_ring_ctx *ctx)
{
struct io_napi_entry *e;
- unsigned int i;
spin_lock(&ctx->napi_lock);
- hash_for_each(ctx->napi_ht, i, e, node) {
+ 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);
}
--
2.46.1
next prev parent reply other threads:[~2024-09-18 12:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-18 12:59 [PATCH v3 0/3] napi tracking strategy Olivier Langlois
2024-09-18 12:59 ` [PATCH v3 1/3] io_uring/napi: protect concurrent io_napi_entry timeout accesses Olivier Langlois
2024-09-18 12:59 ` Olivier Langlois [this message]
2024-09-18 12:59 ` [PATCH v3 3/3] io_uring/napi: add static napi tracking strategy Olivier Langlois
2024-09-19 2:59 ` Jens Axboe
2024-09-19 2:36 ` [PATCH v3 0/3] " Jens Axboe
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