On Mon, Oct 29, 2018 at 3:27 AM Wright Feng <Wright.Feng@xxxxxxxxxxx> wrote: > > Linux 3.6 introduces TSQ which has a per socket threshold for TCP Tx > packets to reduce latency. In fcmode 1 and fcmode 2, host driver enqueues > skb in hanger and TCP doesn't push new skb until host frees the skb when > receiving fwstatus event. So using skb_orphan before sending skb to bus > will make the skb removing the ownership of socket. With this patch, we > are able to get better throughput in fcmode 1 and fcmode 2. > > Tested 43455 TCP throughput in 20 MHz bandwidth with / without this patch. > fcmode 0: 59.5 / 59.6 (mbps) > fcmode 1: 59.3 / 23.4 (mbps) > fcmode 2: 59.6 / 21.5 (mbps) > > Signed-off-by: Wright Feng <wright.feng@xxxxxxxxxxx> > --- > drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c > index b2e1ab5..519b25d 100644 > --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c > +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c > @@ -2298,6 +2298,7 @@ static uint brcmf_sdio_sendfromq(struct brcmf_sdio *bus, uint maxframes) > &prec_out); > if (pkt == NULL) > break; > + skb_orphan(pkt); TSQ allows device driver to tweak for a deeper queue now. [1]. We should use that instead of orphaning the packet before handing over to firmware which would remove the bufferbloat protection by TSQ. Thanks, -Franky [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3a9b76fd0db9f > __skb_queue_tail(&pktq, pkt); > } > spin_unlock_bh(&bus->txq_lock); > -- > 1.9.1 >
