Re: [PATCH V13 01/10] mmc: core: Add parameter use_blk_mq

[Linus Walleij]

On Fri, Nov 3, 2017 at 2:20 PM, Adrian Hunter  wrote:

> Until mmc has blk-mq support fully implemented and tested, add a
> parameter use_blk_mq, default to false unless config option MMC_MQ_DEFAULT
> is selected.
>
> Signed-off-by: Adrian Hunter 
(...)

> +config MMC_MQ_DEFAULT
> +   bool "MMC: use blk-mq I/O path by default"
> +   depends on MMC && BLOCK

default y

The reason being: I want it to be tested, I want it to be deployed.
We should rather use it as a fallback option if something turns out
to be problematic with MQ which, at this point, is highly unlikely.

> +++ b/include/linux/mmc/host.h
> @@ -380,6 +380,7 @@ struct mmc_host {
> unsigned intdoing_retune:1; /* re-tuning in progress */
> unsigned intretune_now:1;   /* do re-tuning at next req */
> unsigned intretune_paused:1; /* re-tuning is temporarily 
> disabled */
> +   unsigned intuse_blk_mq:1;   /* use blk-mq */

unsigned int foo:1 is really a weird way of saying "bool".

We should just fix it I guess, but it's another patch.

Yours,
Linus Walleij

Re: [PATCH V13 01/10] mmc: core: Add parameter use_blk_mq

[Linus Walleij]

On Fri, Nov 3, 2017 at 2:20 PM, Adrian Hunter  wrote:

> Until mmc has blk-mq support fully implemented and tested, add a
> parameter use_blk_mq, default to false unless config option MMC_MQ_DEFAULT
> is selected.
>
> Signed-off-by: Adrian Hunter 
(...)

> +config MMC_MQ_DEFAULT
> +   bool "MMC: use blk-mq I/O path by default"
> +   depends on MMC && BLOCK

default y

The reason being: I want it to be tested, I want it to be deployed.
We should rather use it as a fallback option if something turns out
to be problematic with MQ which, at this point, is highly unlikely.

> +++ b/include/linux/mmc/host.h
> @@ -380,6 +380,7 @@ struct mmc_host {
> unsigned intdoing_retune:1; /* re-tuning in progress */
> unsigned intretune_now:1;   /* do re-tuning at next req */
> unsigned intretune_paused:1; /* re-tuning is temporarily 
> disabled */
> +   unsigned intuse_blk_mq:1;   /* use blk-mq */

unsigned int foo:1 is really a weird way of saying "bool".

We should just fix it I guess, but it's another patch.

Yours,
Linus Walleij

[PATCH V13 01/10] mmc: core: Add parameter use_blk_mq

[Adrian Hunter]

Until mmc has blk-mq support fully implemented and tested, add a
parameter use_blk_mq, default to false unless config option MMC_MQ_DEFAULT
is selected.

Signed-off-by: Adrian Hunter 
---
 drivers/mmc/Kconfig  | 11 +++
 drivers/mmc/core/core.c  |  7 +++
 drivers/mmc/core/core.h  |  2 ++
 drivers/mmc/core/host.c  |  2 ++
 drivers/mmc/core/host.h  |  4 
 include/linux/mmc/host.h |  1 +
 6 files changed, 27 insertions(+)

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index ec21388311db..98202934bd29 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -12,6 +12,17 @@ menuconfig MMC
  If you want MMC/SD/SDIO support, you should say Y here and
  also to your specific host controller driver.
 
+config MMC_MQ_DEFAULT
+   bool "MMC: use blk-mq I/O path by default"
+   depends on MMC && BLOCK
+   ---help---
+ This option enables the new blk-mq based I/O path for MMC block
+ devices by default.  With the option the mmc_core.use_blk_mq
+ module/boot option defaults to Y, without it to N, but it can
+ still be overridden either way.
+
+ If unsure say N.
+
 if MMC
 
 source "drivers/mmc/core/Kconfig"
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1f0f44f4dd5f..5df03cb73be7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -66,6 +66,13 @@
 bool use_spi_crc = 1;
 module_param(use_spi_crc, bool, 0);
 
+#ifdef CONFIG_MMC_MQ_DEFAULT
+bool mmc_use_blk_mq = true;
+#else
+bool mmc_use_blk_mq = false;
+#endif
+module_param_named(use_blk_mq, mmc_use_blk_mq, bool, S_IWUSR | S_IRUGO);
+
 static int mmc_schedule_delayed_work(struct delayed_work *work,
 unsigned long delay)
 {
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 71e6c6d7ceb7..8c5dd8d31400 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -35,6 +35,8 @@ struct mmc_bus_ops {
int (*reset)(struct mmc_host *);
 };
 
+extern bool mmc_use_blk_mq;
+
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
 void mmc_detach_bus(struct mmc_host *host);
 
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 35a9e4fd1a9f..62ef6cb0ece4 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -404,6 +404,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device 
*dev)
 
host->fixed_drv_type = -EINVAL;
 
+   host->use_blk_mq = mmc_use_blk_mq;
+
return host;
 }
 
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index fb689a1065ed..6eaf558e62d6 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -74,6 +74,10 @@ static inline bool mmc_card_hs400es(struct mmc_card *card)
return card->host->ios.enhanced_strobe;
 }
 
+static inline bool mmc_host_use_blk_mq(struct mmc_host *host)
+{
+   return host->use_blk_mq;
+}
 
 #endif
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index e7743eca1021..ce2075d6f429 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -380,6 +380,7 @@ struct mmc_host {
unsigned intdoing_retune:1; /* re-tuning in progress */
unsigned intretune_now:1;   /* do re-tuning at next req */
unsigned intretune_paused:1; /* re-tuning is temporarily 
disabled */
+   unsigned intuse_blk_mq:1;   /* use blk-mq */
 
int rescan_disable; /* disable card detection */
int rescan_entered; /* used with nonremovable 
devices */
-- 
1.9.1

[PATCH V13 01/10] mmc: core: Add parameter use_blk_mq

[Adrian Hunter]

Until mmc has blk-mq support fully implemented and tested, add a
parameter use_blk_mq, default to false unless config option MMC_MQ_DEFAULT
is selected.

Signed-off-by: Adrian Hunter 
---
 drivers/mmc/Kconfig  | 11 +++
 drivers/mmc/core/core.c  |  7 +++
 drivers/mmc/core/core.h  |  2 ++
 drivers/mmc/core/host.c  |  2 ++
 drivers/mmc/core/host.h  |  4 
 include/linux/mmc/host.h |  1 +
 6 files changed, 27 insertions(+)

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index ec21388311db..98202934bd29 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -12,6 +12,17 @@ menuconfig MMC
  If you want MMC/SD/SDIO support, you should say Y here and
  also to your specific host controller driver.
 
+config MMC_MQ_DEFAULT
+   bool "MMC: use blk-mq I/O path by default"
+   depends on MMC && BLOCK
+   ---help---
+ This option enables the new blk-mq based I/O path for MMC block
+ devices by default.  With the option the mmc_core.use_blk_mq
+ module/boot option defaults to Y, without it to N, but it can
+ still be overridden either way.
+
+ If unsure say N.
+
 if MMC
 
 source "drivers/mmc/core/Kconfig"
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1f0f44f4dd5f..5df03cb73be7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -66,6 +66,13 @@
 bool use_spi_crc = 1;
 module_param(use_spi_crc, bool, 0);
 
+#ifdef CONFIG_MMC_MQ_DEFAULT
+bool mmc_use_blk_mq = true;
+#else
+bool mmc_use_blk_mq = false;
+#endif
+module_param_named(use_blk_mq, mmc_use_blk_mq, bool, S_IWUSR | S_IRUGO);
+
 static int mmc_schedule_delayed_work(struct delayed_work *work,
 unsigned long delay)
 {
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 71e6c6d7ceb7..8c5dd8d31400 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -35,6 +35,8 @@ struct mmc_bus_ops {
int (*reset)(struct mmc_host *);
 };
 
+extern bool mmc_use_blk_mq;
+
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
 void mmc_detach_bus(struct mmc_host *host);
 
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 35a9e4fd1a9f..62ef6cb0ece4 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -404,6 +404,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device 
*dev)
 
host->fixed_drv_type = -EINVAL;
 
+   host->use_blk_mq = mmc_use_blk_mq;
+
return host;
 }
 
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index fb689a1065ed..6eaf558e62d6 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -74,6 +74,10 @@ static inline bool mmc_card_hs400es(struct mmc_card *card)
return card->host->ios.enhanced_strobe;
 }
 
+static inline bool mmc_host_use_blk_mq(struct mmc_host *host)
+{
+   return host->use_blk_mq;
+}
 
 #endif
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index e7743eca1021..ce2075d6f429 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -380,6 +380,7 @@ struct mmc_host {
unsigned intdoing_retune:1; /* re-tuning in progress */
unsigned intretune_now:1;   /* do re-tuning at next req */
unsigned intretune_paused:1; /* re-tuning is temporarily 
disabled */
+   unsigned intuse_blk_mq:1;   /* use blk-mq */
 
int rescan_disable; /* disable card detection */
int rescan_entered; /* used with nonremovable 
devices */
-- 
1.9.1