On Wed, May 13, 2020 at 04:38:03PM +0200, Phil Sutter wrote:
> The function tries to insert handles into JSON input for echo option.
> Yet there may be nothing to do if the given netlink message doesn't
> contain a handle, e.g. if it is an 'add element' command. Calling
> seqnum_to_json() is pointless overhead in that case, and if input is
> large this overhead is significant. Better wait with that call until
> after checking if the message is relevant at all.
>
> Signed-off-by: Phil Sutter <phil@xxxxxx>
> ---
> src/parser_json.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/src/parser_json.c b/src/parser_json.c
> index 4468407b0ecd0..3a84bd96af31f 100644
> --- a/src/parser_json.c
> +++ b/src/parser_json.c
> @@ -3847,12 +3847,15 @@ static uint64_t handle_from_nlmsg(const struct nlmsghdr *nlh)
> }
> int json_events_cb(const struct nlmsghdr *nlh, struct netlink_mon_handler *monh)
> {
> - json_t *tmp, *json = seqnum_to_json(nlh->nlmsg_seq);
> uint64_t handle = handle_from_nlmsg(nlh);
> + json_t *tmp, *json;
> void *iter;
>
> - /* might be anonymous set, ignore message */
> - if (!json || !handle)
> + if (!handle)
> + return MNL_CB_OK;
> +
> + json = seqnum_to_json(nlh->nlmsg_seq);
> + if (!json)
> return MNL_CB_OK;
>
> tmp = json_object_get(json, "add");
> --
> 2.26.2
Acked-by: Eric Garver <eric@xxxxxxxxxxx>
With this I see a 10x improvement when adding many (hundreds) set
elements [1].
Thanks Phil!
[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1834853#c6
