* [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option
@ 2014-09-30 15:20 Christoph Hellwig
2014-09-30 21:57 ` Martin K. Petersen
2014-10-01 1:02 ` Elliott, Robert (Server Storage)
0 siblings, 2 replies; 4+ messages in thread
From: Christoph Hellwig @ 2014-09-30 15:20 UTC (permalink / raw)
To: linux-scsi; +Cc: Robert Elliott, Martin K. Petersen
Add a Kconfig option to enable the blk-mq path for SCSI by default
to ease testing and deployment in setups that know they benefit
from blk-mq.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/scsi/Kconfig | 11 +++++++++++
drivers/scsi/scsi.c | 4 ++++
2 files changed, 15 insertions(+)
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 18a3358..71b0877 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -45,6 +45,17 @@ config SCSI_NETLINK
default n
select NET
+config SCSI_MQ_DEFAULT
+ bool "SCSI: use blk-mq I/O path by default"
+ depends on SCSI
+ ---help---
+ This option enables the new blk-mq based I/O path for SCSI
+ devices by default. With the option the scsi_mod.use_blk_mq
+ module/boot option defaults to Y, without it to N, but it can
+ still be overriden either way.
+
+ If unsure say N.
+
config SCSI_PROC_FS
bool "legacy /proc/scsi/ support"
depends on SCSI && PROC_FS
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 1423cb1..79c77b4 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -1367,7 +1367,11 @@ MODULE_LICENSE("GPL");
module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
+#ifdef CONFIG_SCSI_MQ_DEFAULT
+bool scsi_use_blk_mq = true;
+#else
bool scsi_use_blk_mq = false;
+#endif
module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
static int __init init_scsi(void)
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option
2014-09-30 15:20 [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option Christoph Hellwig
@ 2014-09-30 21:57 ` Martin K. Petersen
2014-10-01 1:02 ` Elliott, Robert (Server Storage)
1 sibling, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2014-09-30 21:57 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-scsi, Robert Elliott, Martin K. Petersen
>>>>> "Christoph" == Christoph Hellwig <hch@lst.de> writes:
Christoph> Add a Kconfig option to enable the blk-mq path for SCSI by
Christoph> default to ease testing and deployment in setups that know
Christoph> they benefit from blk-mq.
Looks OK to me.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option
2014-09-30 15:20 [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option Christoph Hellwig
2014-09-30 21:57 ` Martin K. Petersen
@ 2014-10-01 1:02 ` Elliott, Robert (Server Storage)
2014-10-01 8:08 ` Christoph Hellwig
1 sibling, 1 reply; 4+ messages in thread
From: Elliott, Robert (Server Storage) @ 2014-10-01 1:02 UTC (permalink / raw)
To: Christoph Hellwig, linux-scsi@vger.kernel.org; +Cc: Martin K. Petersen
> -----Original Message-----
> From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi-
> owner@vger.kernel.org] On Behalf Of Christoph Hellwig
...
> Add a Kconfig option to enable the blk-mq path for SCSI by default
> to ease testing and deployment in setups that know they benefit
> from blk-mq.
...
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index 1423cb1..79c77b4 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -1367,7 +1367,11 @@ MODULE_LICENSE("GPL");
> module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
> MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
>
> +#ifdef CONFIG_SCSI_MQ_DEFAULT
> +bool scsi_use_blk_mq = true;
> +#else
> bool scsi_use_blk_mq = false;
> +#endif
> module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
>
> static int __init init_scsi(void)
A printk indicating the choice would be helpful; there's no indication
in the "Command line" or "Kernel command line" lines after this patch.
Reviewed-by: Robert Elliott <elliott@hp.com>
Tested-by: Robert Elliott <elliott@hp.com>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option
2014-10-01 1:02 ` Elliott, Robert (Server Storage)
@ 2014-10-01 8:08 ` Christoph Hellwig
0 siblings, 0 replies; 4+ messages in thread
From: Christoph Hellwig @ 2014-10-01 8:08 UTC (permalink / raw)
To: Elliott, Robert (Server Storage)
Cc: Christoph Hellwig, linux-scsi@vger.kernel.org, Martin K. Petersen
On Wed, Oct 01, 2014 at 01:02:32AM +0000, Elliott, Robert (Server Storage) wrote:
> A printk indicating the choice would be helpful; there's no indication
> in the "Command line" or "Kernel command line" lines after this patch.
No need for a printk to further increase the gigantic kernel log at boot
time, you can easily find the indicator in the use_blk_mq sysfs attributes,
both on the module, and each individual host.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-10-01 8:08 UTC | newest]
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2014-09-30 15:20 [PATCH] scsi: add a CONFIG_SCSI_MQ_DEFAULT option Christoph Hellwig
2014-09-30 21:57 ` Martin K. Petersen
2014-10-01 1:02 ` Elliott, Robert (Server Storage)
2014-10-01 8:08 ` Christoph Hellwig
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