Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request
size based on read-ahead setting") removes unneeded split of read requests.
Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup
limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
This patch updates io_pages after merging limits in disk_stack_limits().
Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed
the same problem for device-mapper devices, this one fixes MD RAIDs.
Signed-off-by: Konstantin Khlebnikov <[email protected]>
---
block/blk-settings.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index c8eda2e7b91e..66c45fd79545 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
top, bottom);
}
+
+ t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9);
}
EXPORT_SYMBOL(disk_stack_limits);
Dear Konstantin,
Thank you for the patch.
On 2020-02-28 15:51, Konstantin Khlebnikov wrote:
> Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request
> size based on read-ahead setting") removes unneeded split of read requests.
>
> Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup
The verb is spelled with a space *set up*.
> limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
> Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
>
> This patch updates io_pages after merging limits in disk_stack_limits().
>
> Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed
> the same problem for device-mapper devices, this one fixes MD RAIDs.
Add a Fixes: tag?
Fixes: 9491ae4aade6 ("mm: don't cap request size based on read-ahead setting")
> Signed-off-by: Konstantin Khlebnikov <[email protected]>
> ---
> block/blk-settings.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index c8eda2e7b91e..66c45fd79545 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
> printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
> top, bottom);
> }
> +
> + t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9);
> }
> EXPORT_SYMBOL(disk_stack_limits);
Reviewed-by: Paul Menzel <[email protected]>
Kind regards,
Paul
On 02/03/2020 13.41, Paul Menzel wrote:
> Dear Konstantin,
>
>
> Thank you for the patch.
>
>
> On 2020-02-28 15:51, Konstantin Khlebnikov wrote:
>> Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request
>> size based on read-ahead setting") removes unneeded split of read requests.
>>
>> Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup
>
> The verb is spelled with a space *set up*.
>
>> limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
>> Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
>>
>> This patch updates io_pages after merging limits in disk_stack_limits().
>>
>> Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed
>> the same problem for device-mapper devices, this one fixes MD RAIDs.
>
> Add a Fixes: tag?
>
> Fixes: 9491ae4aade6 ("mm: don't cap request size based on read-ahead setting")
Maybe, but this isn't fatal bug. Just incomplete fix.
Same problem exists for non-disk BDIs. I.e. network filesystem must
set io_pages manually if doesn't want split read requests.
>
>> Signed-off-by: Konstantin Khlebnikov <[email protected]>
>> ---
>> block/blk-settings.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/block/blk-settings.c b/block/blk-settings.c
>> index c8eda2e7b91e..66c45fd79545 100644
>> --- a/block/blk-settings.c
>> +++ b/block/blk-settings.c
>> @@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
>> printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
>> top, bottom);
>> }
>> +
>> + t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9);
>> }
>> EXPORT_SYMBOL(disk_stack_limits);
>
> Reviewed-by: Paul Menzel <[email protected]>
>
>
> Kind regards,
>
> Paul
>
On 2/28/20 10:51 PM, Konstantin Khlebnikov wrote:
> Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request
> size based on read-ahead setting") removes unneeded split of read requests.
>
> Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup
> limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
> Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
>
> This patch updates io_pages after merging limits in disk_stack_limits().
>
> Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed
> the same problem for device-mapper devices, this one fixes MD RAIDs.
>
> Signed-off-by: Konstantin Khlebnikov <[email protected]>
> ---
> block/blk-settings.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index c8eda2e7b91e..66c45fd79545 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
> printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
> top, bottom);
> }
> +
> + t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9);
> }
> EXPORT_SYMBOL(disk_stack_limits);
>
>
Nitpick.. (PAGE_SHIFT - 9)
Reviewed-by: Bob Liu <[email protected]>
On Mon, Mar 2, 2020 at 4:16 AM Bob Liu <[email protected]> wrote:
>
> On 2/28/20 10:51 PM, Konstantin Khlebnikov wrote:
> > Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request
> > size based on read-ahead setting") removes unneeded split of read requests.
> >
> > Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup
> > limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
> > Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
> >
> > This patch updates io_pages after merging limits in disk_stack_limits().
> >
> > Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed
> > the same problem for device-mapper devices, this one fixes MD RAIDs.
> >
> > Signed-off-by: Konstantin Khlebnikov <[email protected]>
> > ---
> > block/blk-settings.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/block/blk-settings.c b/block/blk-settings.c
> > index c8eda2e7b91e..66c45fd79545 100644
> > --- a/block/blk-settings.c
> > +++ b/block/blk-settings.c
> > @@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
> > printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
> > top, bottom);
> > }
> > +
> > + t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9);
> > }
> > EXPORT_SYMBOL(disk_stack_limits);
> >
> >
>
> Nitpick.. (PAGE_SHIFT - 9)
> Reviewed-by: Bob Liu <[email protected]>
Thanks for the fix. I fixed it based on the comments and applied it to md-next.
Jens, I picked the patch to md-next because md is the only user of
disk_stack_limits().
Please let me know if you prefer routing it via the block tree.
Thanks,
Song
On 3/10/20 3:40 PM, Song Liu wrote:
> On Mon, Mar 2, 2020 at 4:16 AM Bob Liu <[email protected]> wrote:
>>
>> On 2/28/20 10:51 PM, Konstantin Khlebnikov wrote:
>>> Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request
>>> size based on read-ahead setting") removes unneeded split of read requests.
>>>
>>> Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup
>>> limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
>>> Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
>>>
>>> This patch updates io_pages after merging limits in disk_stack_limits().
>>>
>>> Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed
>>> the same problem for device-mapper devices, this one fixes MD RAIDs.
>>>
>>> Signed-off-by: Konstantin Khlebnikov <[email protected]>
>>> ---
>>> block/blk-settings.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/block/blk-settings.c b/block/blk-settings.c
>>> index c8eda2e7b91e..66c45fd79545 100644
>>> --- a/block/blk-settings.c
>>> +++ b/block/blk-settings.c
>>> @@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
>>> printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
>>> top, bottom);
>>> }
>>> +
>>> + t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9);
>>> }
>>> EXPORT_SYMBOL(disk_stack_limits);
>>>
>>>
>>
>> Nitpick.. (PAGE_SHIFT - 9)
>> Reviewed-by: Bob Liu <[email protected]>
>
> Thanks for the fix. I fixed it based on the comments and applied it to md-next.
>
> Jens, I picked the patch to md-next because md is the only user of
> disk_stack_limits().
>
> Please let me know if you prefer routing it via the block tree.
That's fine, thanks.
--
Jens Axboe