> -----Original Message----- > From: Sagi Grimberg [mailto:[email protected]] > Sent: Monday, July 06, 2015 2:51 AM > To: Steve Wise; [email protected] > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected] > Subject: Re: [PATCH V5 3/5] RDMA/iser: Limit sg tablesize and max_sectors to > device fastreg max depth > > On 7/5/2015 8:44 PM, Steve Wise wrote: > > Currently the sg tablesize, which dictates fast register page list > > depth to use, does not take into account the limits of the rdma device. > > So adjust it once we discover the device fastreg max depth limit. Also > > adjust the max_sectors based on the resulting sg tablesize. > > > > Signed-off-by: Steve Wise <[email protected]> > > --- > > > > drivers/infiniband/ulp/iser/iscsi_iser.c | 9 +++++++++ > > 1 files changed, 9 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c > > b/drivers/infiniband/ulp/iser/iscsi_iser.c > > index 6a594aa..de8730d 100644 > > --- a/drivers/infiniband/ulp/iser/iscsi_iser.c > > +++ b/drivers/infiniband/ulp/iser/iscsi_iser.c > > @@ -640,6 +640,15 @@ iscsi_iser_session_create(struct iscsi_endpoint *ep, > > SHOST_DIX_GUARD_CRC); > > } > > > > + /* > > + * Limit the sg_tablesize and max_sectors based on the device > > + * max fastreg page list length. > > + */ > > + shost->sg_tablesize = min_t(unsigned short, shost->sg_tablesize, > > + ib_conn->device->dev_attr.max_fast_reg_page_list_len); > > + shost->max_sectors = min_t(unsigned int, > > + 1024, (shost->sg_tablesize * PAGE_SIZE) >> 9); > > + > > The min statement is meaningless for max_sectors - you do a min between > default sg_tablesize and frpl length - so the maximum sg_tablesize is > 128 which is 1024 max_sectors.
I'm not following. What if ib_conn->device->dev_attr.max_fast_reg_page_list_len is say, 32? Then shost->sg_tablesize is set to 32, and max_sectors is set to (32*4K) >> 9 == 256 512B sectors. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
