Re: [PATCH] RDMA/mana_ib: Use v2 version of cfg_rx_steer_req to enable RX coalescing

From: Leon Romanovsky
Date: Mon May 08 2023 - 02:09:48 EST


On Sun, May 07, 2023 at 09:39:27PM +0000, Haiyang Zhang wrote:
>
>
> > -----Original Message-----
> > From: Leon Romanovsky <leon@xxxxxxxxxx>
> > Sent: Sunday, May 7, 2023 4:11 AM
> > To: Long Li <longli@xxxxxxxxxxxxx>
> > Cc: Jason Gunthorpe <jgg@xxxxxxxx>; Ajay Sharma
> > <sharmaajay@xxxxxxxxxxxxx>; Dexuan Cui <decui@xxxxxxxxxxxxx>; KY
> > Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>;
> > Wei Liu <wei.liu@xxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>; Eric
> > Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo
> > Abeni <pabeni@xxxxxxxxxx>; linux-rdma@xxxxxxxxxxxxxxx; linux-
> > hyperv@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx
> > Subject: Re: [PATCH] RDMA/mana_ib: Use v2 version of cfg_rx_steer_req to
> > enable RX coalescing
> >
> > On Fri, May 05, 2023 at 11:51:48AM -0700, longli@xxxxxxxxxxxxxxxxx
> > wrote:
> > > From: Long Li <longli@xxxxxxxxxxxxx>
> > >
> > > With RX coalescing, one CQE entry can be used to indicate multiple packets
> > > on the receive queue. This saves processing time and PCI bandwidth over
> > > the CQ.
> > >
> > > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> > > ---
> > > drivers/infiniband/hw/mana/qp.c | 5 ++++-
> > > include/net/mana/mana.h | 17 +++++++++++++++++
> > > 2 files changed, 21 insertions(+), 1 deletion(-)
> >
> > Why didn't you change mana_cfg_vport_steering() too?
>
> The mana_cfg_vport_steering() is for mana_en (Enthernet) driver, not the
> mana_ib driver.
>
> The changes for mana_en will be done in a separate patch together with
> changes for mana_en RX code patch to support multiple packets / CQE.

I'm aware of the difference between mana_en and mana_ib.

The change you proposed doesn't depend on "support multiple packets / CQE."
and works perfectly with one packet/CQE also, does it?

Thanks

>
> Thanks,
> - Haiyang
>