On 2018/10/30 上午 02:50, Franky Lin wrote: > 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 > Since the aggregation problem has been fixed by setting sk_pacing_shift, I will submit v2 without this one. Thanks for the information. -Wright > [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 >>
