2022-11-24 14:18:52

by Li Nan

Subject: [PATCH -next 2/2] blk-iocost: change div64_u64 to DIV64_U64_ROUND_UP in ioc_refresh_params()

vrate_min is calculated by DIV64_U64_ROUND_UP, but vrate_max is calculated
by div64_u64. Vrate_min may be 1 greater than vrate_max if the input
values min and max of cost.qos are equal.

Signed-off-by: Li Nan <[email protected]>
---
block/blk-iocost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index a38a5324bf10..9030ad8672f3 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -926,7 +926,7 @@ static bool ioc_refresh_params(struct ioc *ioc, bool force)

ioc->vrate_min = DIV64_U64_ROUND_UP((u64)ioc->params.qos[QOS_MIN] *
VTIME_PER_USEC, MILLION);
- ioc->vrate_max = div64_u64((u64)ioc->params.qos[QOS_MAX] *
+ ioc->vrate_max = DIV64_U64_ROUND_UP((u64)ioc->params.qos[QOS_MAX] *
VTIME_PER_USEC, MILLION);

return true;
--
2.31.1

2022-11-25 11:25:34

by Andreas Herrmann

Subject: Re: [PATCH -next 2/2] blk-iocost: change div64_u64 to DIV64_U64_ROUND_UP in ioc_refresh_params()

On Thu, Nov 24, 2022 at 10:06:35PM +0800, Li Nan wrote:
> vrate_min is calculated by DIV64_U64_ROUND_UP, but vrate_max is calculated
> by div64_u64. Vrate_min may be 1 greater than vrate_max if the input
> values min and max of cost.qos are equal.
>
> Signed-off-by: Li Nan <[email protected]>
> ---
> block/blk-iocost.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Andreas Herrmann <[email protected]>

> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index a38a5324bf10..9030ad8672f3 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -926,7 +926,7 @@ static bool ioc_refresh_params(struct ioc *ioc, bool force)
>
> ioc->vrate_min = DIV64_U64_ROUND_UP((u64)ioc->params.qos[QOS_MIN] *
> VTIME_PER_USEC, MILLION);
> - ioc->vrate_max = div64_u64((u64)ioc->params.qos[QOS_MAX] *
> + ioc->vrate_max = DIV64_U64_ROUND_UP((u64)ioc->params.qos[QOS_MAX] *
> VTIME_PER_USEC, MILLION);
>
> return true;
> --
> 2.31.1
>

--
Regards,
Andreas

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