Re: [PATCH] net: bridge: Slightly optimize 'find_portno()'
From: Nikolay Aleksandrov <hidden>
Date: 2021-11-15 12:58:45
Also in:
bridge, kernel-janitors, lkml
On 14/11/2021 21:02, Christophe JAILLET wrote:
quoted hunk ↗ jump to hunk
The 'inuse' bitmap is local to this function. So we can use the non-atomic '__set_bit()' to save a few cycles. While at it, also remove some useless {}. Signed-off-by: Christophe JAILLET <redacted> --- net/bridge/br_if.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index c1183fef1f21..64b2d4fb50f5 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c@@ -397,10 +397,10 @@ static int find_portno(struct net_bridge *br) if (!inuse) return -ENOMEM; - set_bit(0, inuse); /* zero is reserved */ - list_for_each_entry(p, &br->port_list, list) { - set_bit(p->port_no, inuse); - } + __set_bit(0, inuse); /* zero is reserved */ + list_for_each_entry(p, &br->port_list, list) + __set_bit(p->port_no, inuse); + index = find_first_zero_bit(inuse, BR_MAX_PORTS); bitmap_free(inuse);
This should be targeted at net-next. The patch itself looks ok, TBH it's a slow path so speed doesn't really matter but it's a straight-forward change. Acked-by: Nikolay Aleksandrov <redacted>