From 92074c16a8dda83d79c4e9a534757b0e116f7157 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Sat, 19 Mar 2022 00:33:46 +0100 Subject: tcp_splice: Close sockets right away on high number of open files We can't take for granted that the hard limit for open files is big enough as to allow to delay closing sockets to a timer. Store the value of RTLIMIT_NOFILE we set at start, and use it to understand if we're approaching the limit with pending, spliced TCP connections. If that's the case, close sockets right away as soon as they're not needed, instead of deferring this task to a timer. Signed-off-by: Stefano Brivio --- tcp_splice.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) (limited to 'tcp_splice.c') diff --git a/tcp_splice.c b/tcp_splice.c index d374785..b7bdfc2 100644 --- a/tcp_splice.c +++ b/tcp_splice.c @@ -52,6 +52,7 @@ #define TCP_SPLICE_MAX_CONNS (128 * 1024) #define TCP_SPLICE_PIPE_POOL_SIZE 16 #define REFILL_INTERVAL 1000 /* ms, refill pool of pipes */ +#define TCP_SPLICE_FILE_PRESSURE 30 /* % of c->nofile */ /* From tcp.c */ extern int init_sock_pool4 [TCP_SOCK_POOL_SIZE]; @@ -152,6 +153,7 @@ static void tcp_splice_conn_epoll_events(uint16_t events, *b |= (events & SPLICE_B_OUT_WAIT) ? EPOLLOUT : 0; } +static void tcp_splice_destroy(struct ctx *c, struct tcp_splice_conn *conn); static int tcp_splice_epoll_ctl(struct ctx *c, struct tcp_splice_conn *conn); /** @@ -832,13 +834,9 @@ void tcp_splice_init(struct ctx *c) */ void tcp_splice_timer(struct ctx *c, struct timespec *now) { - int i; - - for (i = c->tcp.splice_conn_count - 1; i >= 0; i--) { - struct tcp_splice_conn *conn; - - conn = CONN(i); + struct tcp_splice_conn *conn; + for (conn = CONN(c->tcp.splice_conn_count - 1); conn >= tc; conn--) { if (conn->flags & SPLICE_CLOSING) { tcp_splice_destroy(c, conn); continue; @@ -865,3 +863,21 @@ void tcp_splice_timer(struct ctx *c, struct timespec *now) if (timespec_diff_ms(now, &c->tcp.refill_ts) > REFILL_INTERVAL) tcp_splice_pipe_refill(c); } + +/** + * tcp_splice_defer_handler() - Close connections without timer on file pressure + * @c: Execution context + */ +void tcp_splice_defer_handler(struct ctx *c) +{ + int max_files = c->nofile / 100 * TCP_SPLICE_FILE_PRESSURE; + struct tcp_splice_conn *conn; + + if (c->tcp.splice_conn_count * 6 < max_files) + return; + + for (conn = CONN(c->tcp.splice_conn_count - 1); conn >= tc; conn--) { + if (conn->flags & SPLICE_CLOSING) + tcp_splice_destroy(c, conn); + } +} -- cgit v1.2.3