* [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-20 16:38 ` Arnd Bergmann
0 siblings, 0 replies; 12+ messages in thread
From: Arnd Bergmann @ 2015-11-20 16:38 UTC (permalink / raw)
To: linux-arm-kernel
do_div is the wrong way to divide a sector_t, as it is less
efficient when sector_t is 32-bit wide. With the upcoming
do_div optimizations, the kernel starts warning about this:
drivers/scsi/scsi_debug.c: In function 'dif_store':
include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
This changes the code to use sector_div instead, which always
produces optimal code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Found on the ARM randconfig build today, after I merged Nico's patches
for linux-next
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index dfcc45bb03b1..ec622ba9864a 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
static struct sd_dif_tuple *dif_store(sector_t sector)
{
- sector = do_div(sector, sdebug_store_sectors);
+ sector = sector_div(sector, sdebug_store_sectors);
return dif_storep + sector;
}
@@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t lba)
lba += scsi_debug_unmap_granularity -
scsi_debug_unmap_alignment;
}
- do_div(lba, scsi_debug_unmap_granularity);
+ sector_div(lba, scsi_debug_unmap_granularity);
return lba;
}
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH] scsi: use sector_div instead of do_div
2015-11-20 16:38 ` Arnd Bergmann
(?)
@ 2015-11-24 12:48 ` Johannes Thumshirn
-1 siblings, 0 replies; 12+ messages in thread
From: Johannes Thumshirn @ 2015-11-24 12:48 UTC (permalink / raw)
To: Arnd Bergmann, linux-scsi
Cc: jbottomley, martin.petersen, nico, linux-kernel, linux-arm-kernel
On Fri, 2015-11-20 at 17:38 +0100, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct
> pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Found on the ARM randconfig build today, after I merged Nico's
> patches
> for linux-next
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index dfcc45bb03b1..ec622ba9864a 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
>
> static struct sd_dif_tuple *dif_store(sector_t sector)
> {
> - sector = do_div(sector, sdebug_store_sectors);
> + sector = sector_div(sector, sdebug_store_sectors);
>
> return dif_storep + sector;
> }
> @@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t
> lba)
> lba += scsi_debug_unmap_granularity -
> scsi_debug_unmap_alignment;
> }
> - do_div(lba, scsi_debug_unmap_granularity);
> + sector_div(lba, scsi_debug_unmap_granularity);
>
> return lba;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi"
> in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-24 12:48 ` Johannes Thumshirn
0 siblings, 0 replies; 12+ messages in thread
From: Johannes Thumshirn @ 2015-11-24 12:48 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, 2015-11-20 at 17:38 +0100, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct
> pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Found on the ARM randconfig build today, after I merged Nico's
> patches
> for linux-next
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index dfcc45bb03b1..ec622ba9864a 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
> ?
> ?static struct sd_dif_tuple *dif_store(sector_t sector)
> ?{
> - sector = do_div(sector, sdebug_store_sectors);
> + sector = sector_div(sector, sdebug_store_sectors);
> ?
> ? return dif_storep + sector;
> ?}
> @@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t
> lba)
> ? lba += scsi_debug_unmap_granularity -
> ? scsi_debug_unmap_alignment;
> ? }
> - do_div(lba, scsi_debug_unmap_granularity);
> + sector_div(lba, scsi_debug_unmap_granularity);
> ?
> ? return lba;
> ?}
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi"
> in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at??http://vger.kernel.org/majordomo-info.html
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-24 12:48 ` Johannes Thumshirn
0 siblings, 0 replies; 12+ messages in thread
From: Johannes Thumshirn @ 2015-11-24 12:48 UTC (permalink / raw)
To: Arnd Bergmann, linux-scsi
Cc: jbottomley, martin.petersen, nico, linux-kernel, linux-arm-kernel
On Fri, 2015-11-20 at 17:38 +0100, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct
> pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Found on the ARM randconfig build today, after I merged Nico's
> patches
> for linux-next
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index dfcc45bb03b1..ec622ba9864a 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
>
> static struct sd_dif_tuple *dif_store(sector_t sector)
> {
> - sector = do_div(sector, sdebug_store_sectors);
> + sector = sector_div(sector, sdebug_store_sectors);
>
> return dif_storep + sector;
> }
> @@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t
> lba)
> lba += scsi_debug_unmap_granularity -
> scsi_debug_unmap_alignment;
> }
> - do_div(lba, scsi_debug_unmap_granularity);
> + sector_div(lba, scsi_debug_unmap_granularity);
>
> return lba;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi"
> in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] scsi: use sector_div instead of do_div
2015-11-20 16:38 ` Arnd Bergmann
@ 2015-11-24 12:50 ` Sagi Grimberg
-1 siblings, 0 replies; 12+ messages in thread
From: Sagi Grimberg @ 2015-11-24 12:50 UTC (permalink / raw)
To: Arnd Bergmann, linux-scsi
Cc: jbottomley, martin.petersen, nico, linux-kernel, linux-arm-kernel
On 20/11/2015 18:38, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-24 12:50 ` Sagi Grimberg
0 siblings, 0 replies; 12+ messages in thread
From: Sagi Grimberg @ 2015-11-24 12:50 UTC (permalink / raw)
To: linux-arm-kernel
On 20/11/2015 18:38, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] scsi: use sector_div instead of do_div
2015-11-20 16:38 ` Arnd Bergmann
@ 2015-11-24 15:03 ` Hannes Reinecke
-1 siblings, 0 replies; 12+ messages in thread
From: Hannes Reinecke @ 2015-11-24 15:03 UTC (permalink / raw)
To: Arnd Bergmann, linux-scsi
Cc: jbottomley, martin.petersen, nico, linux-kernel, linux-arm-kernel
On 11/20/2015 05:38 PM, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Found on the ARM randconfig build today, after I merged Nico's patches
> for linux-next
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index dfcc45bb03b1..ec622ba9864a 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
>
> static struct sd_dif_tuple *dif_store(sector_t sector)
> {
> - sector = do_div(sector, sdebug_store_sectors);
> + sector = sector_div(sector, sdebug_store_sectors);
>
> return dif_storep + sector;
> }
> @@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t lba)
> lba += scsi_debug_unmap_granularity -
> scsi_debug_unmap_alignment;
> }
> - do_div(lba, scsi_debug_unmap_granularity);
> + sector_div(lba, scsi_debug_unmap_granularity);
>
> return lba;
> }
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-24 15:03 ` Hannes Reinecke
0 siblings, 0 replies; 12+ messages in thread
From: Hannes Reinecke @ 2015-11-24 15:03 UTC (permalink / raw)
To: linux-arm-kernel
On 11/20/2015 05:38 PM, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
>
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
>
> This changes the code to use sector_div instead, which always
> produces optimal code.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Found on the ARM randconfig build today, after I merged Nico's patches
> for linux-next
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index dfcc45bb03b1..ec622ba9864a 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
>
> static struct sd_dif_tuple *dif_store(sector_t sector)
> {
> - sector = do_div(sector, sdebug_store_sectors);
> + sector = sector_div(sector, sdebug_store_sectors);
>
> return dif_storep + sector;
> }
> @@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t lba)
> lba += scsi_debug_unmap_granularity -
> scsi_debug_unmap_alignment;
> }
> - do_div(lba, scsi_debug_unmap_granularity);
> + sector_div(lba, scsi_debug_unmap_granularity);
>
> return lba;
> }
>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare at suse.de +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg
GF: F. Imend?rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG N?rnberg)
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] scsi: use sector_div instead of do_div
2015-11-20 16:38 ` Arnd Bergmann
(?)
@ 2015-11-26 3:28 ` Martin K. Petersen
-1 siblings, 0 replies; 12+ messages in thread
From: Martin K. Petersen @ 2015-11-26 3:28 UTC (permalink / raw)
To: Arnd Bergmann
Cc: linux-scsi, jbottomley, martin.petersen, nico, linux-kernel,
linux-arm-kernel
>>>>> "Arnd" == Arnd Bergmann <arnd@arndb.de> writes:
Arnd> do_div is the wrong way to divide a sector_t, as it is less
Arnd> efficient when sector_t is 32-bit wide. With the upcoming do_div
Arnd> optimizations, the kernel starts warning about this:
Applied.
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-26 3:28 ` Martin K. Petersen
0 siblings, 0 replies; 12+ messages in thread
From: Martin K. Petersen @ 2015-11-26 3:28 UTC (permalink / raw)
To: linux-arm-kernel
>>>>> "Arnd" == Arnd Bergmann <arnd@arndb.de> writes:
Arnd> do_div is the wrong way to divide a sector_t, as it is less
Arnd> efficient when sector_t is 32-bit wide. With the upcoming do_div
Arnd> optimizations, the kernel starts warning about this:
Applied.
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] scsi: use sector_div instead of do_div
@ 2015-11-26 3:28 ` Martin K. Petersen
0 siblings, 0 replies; 12+ messages in thread
From: Martin K. Petersen @ 2015-11-26 3:28 UTC (permalink / raw)
To: Arnd Bergmann
Cc: linux-scsi, martin.petersen, nico, jbottomley, linux-kernel,
linux-arm-kernel
>>>>> "Arnd" == Arnd Bergmann <arnd@arndb.de> writes:
Arnd> do_div is the wrong way to divide a sector_t, as it is less
Arnd> efficient when sector_t is 32-bit wide. With the upcoming do_div
Arnd> optimizations, the kernel starts warning about this:
Applied.
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 12+ messages in thread