Re: [PATCH] tcp: Close timer fd when removing it from epoll

On Fri, Jan 16, 2026 at 01:55:57PM +0100, Laurent Vivier wrote:

When tcp_epoll_ctl() handles a CLOSED connection, it removes the timer from epoll but leaves the fd open until tcp_flow_defer() eventually closes it.

Close the timer fd immediately when removing it from epoll, since there's no reason to keep an fd around that's no longer monitored. Set conn->timer to -1 to prevent a double-close in tcp_flow_defer().

This seems safe to me, but is there any actual advantage to it?

Signed-off-by: Laurent Vivier --- tcp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tcp.c b/tcp.c index 1db861705ddb..62064efcc1ef 100644 --- a/tcp.c +++ b/tcp.c @@ -535,8 +535,11 @@ static int tcp_epoll_ctl(struct tcp_tap_conn *conn) int epollfd = flow_epollfd(&conn->f);

epoll_del(epollfd, conn->sock); - if (conn->timer != -1) + if (conn->timer != -1) { epoll_del(epollfd, conn->timer); + close(conn->timer); + conn->timer = -1; + } }

return 0; -- 2.52.0

-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson