On Mon, May 21, 2018 at 06:55:53PM +0300, Sergey Gorenko wrote:
> The iSER driver reduces max_sectors. For example, if you load the
> ib_iser module with max_sectors=1024, you will see that
> /sys/class/block/<bdev>/queue/max_hw_sectors_kb is 508. It is an
> incorrect value. The expected value is (max_sectors * sector_size) /
> 1024 = 512.
>
> Reducing of max_sectors can cause performance degradation due to
> unnecessary splitting of IO requests.
>
> The number of pages per MR has been fixed here, so there is no longer
> any need to reduce max_sectors.
>
> Fixes: 9c674815d346 ("IB/iser: Fix max_sectors calculation")
> Signed-off-by: Sergey Gorenko <sergeygo@xxxxxxxxxxxx>
> Reviewed-by: Israel Rukshin <israelr@xxxxxxxxxxxx>
> Reviewed-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
> ---
> drivers/infiniband/ulp/iser/iscsi_iser.c | 12 +++++-------
> drivers/infiniband/ulp/iser/iscsi_iser.h | 2 ++
> drivers/infiniband/ulp/iser/iser_initiator.c | 2 +-
> drivers/infiniband/ulp/iser/iser_verbs.c | 21 ++++++++++++++++++---
> 4 files changed, 26 insertions(+), 11 deletions(-)
Sagi, can you ack/nak this? Seems tricky.
Thanks,
Jason
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
