[openib-general] why sdp connections cost so much memory

[Michael S. Tsirkin]

Quoting r. zhu shi song <zhushisongzhu at yahoo.com>:
> Subject: Re: why sdp connections cost so much memory
> 
> 
> 
> --- "Michael S. Tsirkin" <mst at mellanox.co.il> wrote:
> 
> > Quoting r. zhu shi song <zhushisongzhu at yahoo.com>:
> > > Subject: Re: why sdp connections cost so much
> > memory
> > > 
> > > >> You mean - when only a single socket is open?
> > > Every one connection will cost 2M RAM. So I make
> > the
> > > following changes:
> > > #define SDP_TX_SIZE 0x4
> > > #define SDP_RX_SIZE 0x4
> > 
> > You should not need this change with the scale patch
> > I posted - after applying
> > this, and setting the scale parameter to 0x1, each
> > connection should use around
> > 128K for RX. Please confirm.

Could you please confirm that setting scale factor to 1 works for you,
without changing SDP_TX_SIZE/SDP_RX_SIZE?

> can each connection use 64K  memory?

SDP_MAX_SEND_SKB_FRAGS controls the number of pages per descriptor.
You need at least 4 of these.
I have it at 8 at the moment, try scaling it down.

-- 
MST