Re: [PATCH] iser-target: Disable TX completion interrupt coalescing
On Tue, 2014-10-07 at 09:58 +0300, Sagi Grimberg wrote: On 10/6/2014 5:15 AM, Nicholas A. Bellinger wrote: From: Nicholas Bellinger n...@linux-iscsi.org This patch explicitly disables TX completion interrupt coalescing logic in isert_put_response() and isert_put_datain() that was originally added as an efficiency optimization in commit 95b60f07. It has been reported that this change can trigger ABORT_TASK timeouts under certain small block workloads, where disabling coalescing was required for stability. According to Sagi, this doesn't impact overall performance, so go ahead and disable it for now. Reported-by: Moussa Ba mouss...@micron.com Cc: Moussa Ba mouss...@micron.com Reported-by: Sagi Grimberg sa...@dev.mellanox.co.il Cc: Sagi Grimberg sa...@dev.mellanox.co.il Cc: sta...@vger.kernel.org # 3.13+ Signed-off-by: Nicholas Bellinger n...@linux-iscsi.org --- drivers/infiniband/ulp/isert/ib_isert.c |4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c index 40969b6..f719112 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.c +++ b/drivers/infiniband/ulp/isert/ib_isert.c @@ -2183,7 +2183,7 @@ isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd) isert_cmd-tx_desc.num_sge = 2; } - isert_init_send_wr(isert_conn, isert_cmd, send_wr, true); + isert_init_send_wr(isert_conn, isert_cmd, send_wr, false); I Would like to avoid taking the conn_mutex in the IO path. Yes, please. Care to respin this with avoiding taking the mutex? Or you want me to? Let's keep this patch as is for -rc1 so it can be easily picked up for stable, especially considering that it's been verified by Moussa for some time. I have a couple of patches in the pipe anyway... Thank you Sagi. --nab -- To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] iser-target: Disable TX completion interrupt coalescing
On 10/8/2014 9:01 AM, Nicholas A. Bellinger wrote: On Tue, 2014-10-07 at 09:58 +0300, Sagi Grimberg wrote: On 10/6/2014 5:15 AM, Nicholas A. Bellinger wrote: From: Nicholas Bellinger n...@linux-iscsi.org This patch explicitly disables TX completion interrupt coalescing logic in isert_put_response() and isert_put_datain() that was originally added as an efficiency optimization in commit 95b60f07. It has been reported that this change can trigger ABORT_TASK timeouts under certain small block workloads, where disabling coalescing was required for stability. According to Sagi, this doesn't impact overall performance, so go ahead and disable it for now. Reported-by: Moussa Ba mouss...@micron.com Cc: Moussa Ba mouss...@micron.com Reported-by: Sagi Grimberg sa...@dev.mellanox.co.il Cc: Sagi Grimberg sa...@dev.mellanox.co.il Cc: sta...@vger.kernel.org # 3.13+ Signed-off-by: Nicholas Bellinger n...@linux-iscsi.org --- drivers/infiniband/ulp/isert/ib_isert.c |4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c index 40969b6..f719112 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.c +++ b/drivers/infiniband/ulp/isert/ib_isert.c @@ -2183,7 +2183,7 @@ isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd) isert_cmd-tx_desc.num_sge = 2; } - isert_init_send_wr(isert_conn, isert_cmd, send_wr, true); + isert_init_send_wr(isert_conn, isert_cmd, send_wr, false); I Would like to avoid taking the conn_mutex in the IO path. Yes, please. Care to respin this with avoiding taking the mutex? Or you want me to? Let's keep this patch as is for -rc1 so it can be easily picked up for stable, especially considering that it's been verified by Moussa for some time. OK we can do that. But I do plan to remove this code altogether. I have some fixes and optimizations I want to add and it will be much easier without this code (given its not active). Once those are in, I think it would be easier to handle TX completions coalescing. You can add: acked-by: Sagi Grimberg sa...@dev.mellanox.co.il Sagi. -- To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] iser-target: Disable TX completion interrupt coalescing
On 10/6/2014 5:15 AM, Nicholas A. Bellinger wrote: From: Nicholas Bellinger n...@linux-iscsi.org This patch explicitly disables TX completion interrupt coalescing logic in isert_put_response() and isert_put_datain() that was originally added as an efficiency optimization in commit 95b60f07. It has been reported that this change can trigger ABORT_TASK timeouts under certain small block workloads, where disabling coalescing was required for stability. According to Sagi, this doesn't impact overall performance, so go ahead and disable it for now. Reported-by: Moussa Ba mouss...@micron.com Cc: Moussa Ba mouss...@micron.com Reported-by: Sagi Grimberg sa...@dev.mellanox.co.il Cc: Sagi Grimberg sa...@dev.mellanox.co.il Cc: sta...@vger.kernel.org # 3.13+ Signed-off-by: Nicholas Bellinger n...@linux-iscsi.org --- drivers/infiniband/ulp/isert/ib_isert.c |4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c index 40969b6..f719112 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.c +++ b/drivers/infiniband/ulp/isert/ib_isert.c @@ -2183,7 +2183,7 @@ isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd) isert_cmd-tx_desc.num_sge = 2; } - isert_init_send_wr(isert_conn, isert_cmd, send_wr, true); + isert_init_send_wr(isert_conn, isert_cmd, send_wr, false); I Would like to avoid taking the conn_mutex in the IO path. Care to respin this with avoiding taking the mutex? Or you want me to? I have a couple of patches in the pipe anyway... Sagi. -- To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html