From 988ade6b8e27e79311812f83a87b5cea11fabcd7 Mon Sep 17 00:00:00 2001 From: Krishna Kumar Date: Wed, 14 Oct 2009 19:55:07 +0000 Subject: [PATCH] genetlink: Optimize and one bug fix in genl_generate_id() 1. GENL_MIN_ID is a valid id -> no need to start at GENL_MIN_ID + 1. 2. Avoid going through the ids two times: If we start at GENL_MIN_ID+1 (*or bigger*) and all ids are over!, the code iterates through the list twice (*or lesser*). 3. Simplify code - no need to start at idx=0 which gets reset to GENL_MIN_ID. Patch on net-next-2.6. Reboot test shows that first id passed to genl_register_family was 16, next two were GENL_ID_GENERATE and genl_generate_id returned 17 & 18 (user level testing of same code shows expected values across entire range of MIN/MAX). Signed-off-by: Krishna Kumar Signed-off-by: David S. Miller --- net/netlink/genetlink.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index ddfdb7d2e02b..d07ecda0a92d 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -97,25 +97,17 @@ static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) */ static inline u16 genl_generate_id(void) { - static u16 id_gen_idx; - int overflowed = 0; + static u16 id_gen_idx = GENL_MIN_ID; + int i; - do { - if (id_gen_idx == 0) + for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) { + if (!genl_family_find_byid(id_gen_idx)) + return id_gen_idx; + if (++id_gen_idx > GENL_MAX_ID) id_gen_idx = GENL_MIN_ID; + } - if (++id_gen_idx > GENL_MAX_ID) { - if (!overflowed) { - overflowed = 1; - id_gen_idx = 0; - continue; - } else - return 0; - } - - } while (genl_family_find_byid(id_gen_idx)); - - return id_gen_idx; + return 0; } static struct genl_multicast_group notify_grp; -- 2.30.2