diff mbox series

[RFC,v3,01/14] mm: add bdi_set_strict_limit() function

Message ID 20221024190603.3987969-2-shr@devkernel.io (mailing list archive)
State New
Headers show
Series mm/block: add bdi sysfs knobs | expand

Commit Message

Stefan Roesch Oct. 24, 2022, 7:05 p.m. UTC 
This adds the bdi_set_strict_limit function to be able to set/unset the
BDI_CAP_STRICTLIMIT flag.

Signed-off-by: Stefan Roesch <shr@devkernel.io>
---
 include/linux/backing-dev.h |  1 +
 mm/page-writeback.c         | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

Comments

Andrew Morton Nov. 16, 2022, 9:28 p.m. UTC | #1 
On Mon, 24 Oct 2022 12:05:50 -0700 Stefan Roesch <shr@devkernel.io> wrote:

> This adds the bdi_set_strict_limit function to be able to set/unset the
> BDI_CAP_STRICTLIMIT flag.
> 
> ...
>
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -698,6 +698,22 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
>  }
>  EXPORT_SYMBOL(bdi_set_max_ratio);
>  
> +int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit)
> +{
> +	if (strict_limit > 1)
> +		return -EINVAL;
> +
> +	spin_lock_bh(&bdi_lock);
> +	if (strict_limit)
> +		bdi->capabilities |= BDI_CAP_STRICTLIMIT;
> +	else
> +		bdi->capabilities &= ~BDI_CAP_STRICTLIMIT;
> +	spin_unlock_bh(&bdi_lock);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(bdi_set_strict_limit);

I don't believe the export is needed?
Stefan Roesch Nov. 19, 2022, 12:01 a.m. UTC | #2 
Andrew Morton <akpm@linux-foundation.org> writes:

> On Mon, 24 Oct 2022 12:05:50 -0700 Stefan Roesch <shr@devkernel.io> wrote:
>
>> This adds the bdi_set_strict_limit function to be able to set/unset the
>> BDI_CAP_STRICTLIMIT flag.
>>
>> ...
>>
>> --- a/mm/page-writeback.c
>> +++ b/mm/page-writeback.c
>> @@ -698,6 +698,22 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
>>  }
>>  EXPORT_SYMBOL(bdi_set_max_ratio);
>>
>> +int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit)
>> +{
>> +	if (strict_limit > 1)
>> +		return -EINVAL;
>> +
>> +	spin_lock_bh(&bdi_lock);
>> +	if (strict_limit)
>> +		bdi->capabilities |= BDI_CAP_STRICTLIMIT;
>> +	else
>> +		bdi->capabilities &= ~BDI_CAP_STRICTLIMIT;
>> +	spin_unlock_bh(&bdi_lock);
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(bdi_set_strict_limit);
>
> I don't believe the export is needed?

No, the export is not needed, the next version will remove the export.
diff mbox series

Patch

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 439815cc1ab9..9c984ffc8a0a 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -104,6 +104,7 @@  static inline unsigned long wb_stat_error(void)
 
 int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
 int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
+int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit);
 
 /*
  * Flags in backing_dev_info::capability
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7e9d8d857ecc..e22aae0ecacd 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -698,6 +698,22 @@  int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
 }
 EXPORT_SYMBOL(bdi_set_max_ratio);
 
+int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit)
+{
+	if (strict_limit > 1)
+		return -EINVAL;
+
+	spin_lock_bh(&bdi_lock);
+	if (strict_limit)
+		bdi->capabilities |= BDI_CAP_STRICTLIMIT;
+	else
+		bdi->capabilities &= ~BDI_CAP_STRICTLIMIT;
+	spin_unlock_bh(&bdi_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(bdi_set_strict_limit);
+
 static unsigned long dirty_freerun_ceiling(unsigned long thresh,
 					   unsigned long bg_thresh)
 {