RE: [[PATCH v1] 04/37] [CIFS] SMBD: Define per-channel SMBD transport parameters and default values

[Tom Talpey]

> -----Original Message-----
> From: linux-cifs-owner@xxxxxxxxxxxxxxx [mailto:linux-cifs-
> owner@xxxxxxxxxxxxxxx] On Behalf Of Christoph Hellwig
> Sent: Sunday, August 13, 2017 6:12 AM
> To: Long Li <longli@xxxxxxxxxxxxx>
> Cc: Steve French <sfrench@xxxxxxxxx>; linux-cifs@xxxxxxxxxxxxxxx; samba-
> technical@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Long Li
> <longli@xxxxxxxxxxxxx>
> Subject: Re: [[PATCH v1] 04/37] [CIFS] SMBD: Define per-channel SMBD
> transport parameters and default values
> 
> > +/*
> > + * Per RDMA transport connection parameters
> > + * as defined in [MS-SMBD] 3.1.1.1
> > + */
> > +static int receive_credit_max = 512;
> > +static int send_credit_target = 512;
> > +static int max_send_size = 8192;
> > +static int max_fragmented_recv_size = 1024*1024;
> > +static int max_receive_size = 8192;
> 
> Are these protocol constants?  If so please use either #defines
> or enums with upper case names for them.

These are not defined constants, but the values beg for some explanatory text
why they are chosen. Windows uses, and negotiates by default, a 1364-byte
maximum send size, and caps credits to 255. The other values match.

BTW, the parameters are defined in MS-SMBD 3.1.1.1 but the chosen values
are in behavior notes 2 and 7.

Tom.