On Friday, September 09/11/20, 2020 at 18:41:52 +0530, Leon Romanovsky wrote: > On Thu, Sep 10, 2020 at 07:14:50PM +0000, Potnuri Bharat Teja wrote: > > >> Subject: [PATCH] RDMA/iw_cxgb4: disable delayed ack by default > > >> > > >> Receive side delayed ack mode is needed only for certain area networks/ connections. Therefore disable it by default. > > >> > > >> Signed-off-by: Potnuri Bharat Teja <bharat@xxxxxxxxxxx> > > >> --- > > >> drivers/infiniband/hw/cxgb4/cm.c | 4 ++-- > > >> 1 file changed, 2 insertions(+), 2 deletions(-) > > >> > > >> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c > > >> index 1f288c73ccfc..8769e7aa097f 100644 > > >> --- a/drivers/infiniband/hw/cxgb4/cm.c > > >> +++ b/drivers/infiniband/hw/cxgb4/cm.c > > >> @@ -77,9 +77,9 @@ static int enable_ecn; module_param(enable_ecn, int, 0644); MODULE_PARM_DESC(enable_ecn, "Enable ECN (default=0/disabled)"); > > >> > > >> -static int dack_mode = 1; > > >> +static int dack_mode; > > >> module_param(dack_mode, int, 0644); > > >> -MODULE_PARM_DESC(dack_mode, "Delayed ack mode (default=1)"); > > >> +MODULE_PARM_DESC(dack_mode, "Delayed ack mode (default=0)"); > > > > > >Are you sure that this doesn't break user scripts? > > Yes, I am sure. This does not interfere with user/kernel RDMA functionalities. > > How is it possible? > Before this change user that did "modprobe iw_cxgb4" had delayed mode > enabled, after this he will need to issue "modprobe iw_cxgb4 dack_mode=1" > Sorry I didnt get it right earlier. Yes now if user wants delayed ack mode, user can issue "modprobe iw_cxgb4 dack_mode=1" or change it dynamically via /sys/module/<>/paramters. Chelsio adapters for better performance in most cases needs delayed ack mode to be disabled. This change somehow got missed upstream all this while. In fewer explicit cases, user can enable delayed ack mode where it is needed. > https://github.com/linux-rdma/rdma-core/blob/master/kernel-boot/rdma-hw-modules.rules#L12 > > Thanks > > > > > Thanks, > > Bharat. > > > > > >Thanks > > > > > >> > > >> uint c4iw_max_read_depth = 32; > > >> module_param(c4iw_max_read_depth, int, 0644); > > >> -- > > >> 2.24.0
