[ Upstream commit dae7a75f1f19bffb579daf148f8d8addd2726772 ] Currently, iser target support max IO size of 16MiB by default. For some adapters, allocating this amount of resources might reduce the total number of possible connections that can be created. For those adapters, it's preferred to reduce the max IO size to be able to create more connections. Since there is no handshake procedure for max IO size in iser protocol, set the default max IO size to 1MiB and add a module parameter for enabling the option to control it for suitable adapters. Fixes: 317000b926b0 ("IB/isert: allocate RW ctxs according to max IO size") Link: https://lore.kernel.org/r/20201019094628.17202-1-mgurtovoy@nvidia.com Reported-by: Krishnamraju Eraparaju <krishna2@chelsio.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org>