diff mbox series

[net-next] tcp: tcp_wfree() refactoring

Message ID 20221110190239.3531280-1-edumazet@google.com (mailing list archive)
State Accepted
Commit b548b17a93fd18357a5a6f535c10c1e68719ad32
Delegated to: Netdev Maintainers
Headers show
Series [net-next] tcp: tcp_wfree() refactoring | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 2 maintainers not CCed: yoshfuji@linux-ipv6.org dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 7 this patch: 7
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch warning WARNING: memory barrier without comment
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet Nov. 10, 2022, 7:02 p.m. UTC 
Use try_cmpxchg() (instead of cmpxchg()) in a more readable way.

oval = smp_load_acquire(&sk->sk_tsq_flags);
do {
	...
} while (!try_cmpxchg(&sk->sk_tsq_flags, &oval, nval));

Reduce indentation level.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/tcp_output.c | 31 ++++++++++++++-----------------
 1 file changed, 14 insertions(+), 17 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Nov. 12, 2022, 6 a.m. UTC | #1 
Hello:

This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 10 Nov 2022 19:02:39 +0000 you wrote:
> Use try_cmpxchg() (instead of cmpxchg()) in a more readable way.
> 
> oval = smp_load_acquire(&sk->sk_tsq_flags);
> do {
> 	...
> } while (!try_cmpxchg(&sk->sk_tsq_flags, &oval, nval));
> 
> [...]

Here is the summary with links:
  - [net-next] tcp: tcp_wfree() refactoring
    https://git.kernel.org/netdev/net-next/c/b548b17a93fd

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d1cb1ecf8f216dc810ca08ea35ae752fd19ba706..894410dc9293680d6944a1ad9186f2ab504734eb 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1139,6 +1139,8 @@  void tcp_wfree(struct sk_buff *skb)
 	struct sock *sk = skb->sk;
 	struct tcp_sock *tp = tcp_sk(sk);
 	unsigned long flags, nval, oval;
+	struct tsq_tasklet *tsq;
+	bool empty;
 
 	/* Keep one reference on sk_wmem_alloc.
 	 * Will be released by sk_free() from here or tcp_tasklet_func()
@@ -1155,28 +1157,23 @@  void tcp_wfree(struct sk_buff *skb)
 	if (refcount_read(&sk->sk_wmem_alloc) >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current)
 		goto out;
 
-	for (oval = READ_ONCE(sk->sk_tsq_flags);; oval = nval) {
-		struct tsq_tasklet *tsq;
-		bool empty;
-
+	oval = smp_load_acquire(&sk->sk_tsq_flags);
+	do {
 		if (!(oval & TSQF_THROTTLED) || (oval & TSQF_QUEUED))
 			goto out;
 
 		nval = (oval & ~TSQF_THROTTLED) | TSQF_QUEUED;
-		nval = cmpxchg(&sk->sk_tsq_flags, oval, nval);
-		if (nval != oval)
-			continue;
+	} while (!try_cmpxchg(&sk->sk_tsq_flags, &oval, nval));
 
-		/* queue this socket to tasklet queue */
-		local_irq_save(flags);
-		tsq = this_cpu_ptr(&tsq_tasklet);
-		empty = list_empty(&tsq->head);
-		list_add(&tp->tsq_node, &tsq->head);
-		if (empty)
-			tasklet_schedule(&tsq->tasklet);
-		local_irq_restore(flags);
-		return;
-	}
+	/* queue this socket to tasklet queue */
+	local_irq_save(flags);
+	tsq = this_cpu_ptr(&tsq_tasklet);
+	empty = list_empty(&tsq->head);
+	list_add(&tp->tsq_node, &tsq->head);
+	if (empty)
+		tasklet_schedule(&tsq->tasklet);
+	local_irq_restore(flags);
+	return;
 out:
 	sk_free(sk);
 }