* [PATCH] scsi: ufs: core: sysfs: Prevent div by zero
@ 2024-11-20 6:25 Gwendal Grignou
2024-11-21 20:24 ` Bart Van Assche
2024-11-22 2:09 ` Can Guo
0 siblings, 2 replies; 5+ messages in thread
From: Gwendal Grignou @ 2024-11-20 6:25 UTC (permalink / raw)
To: alim.akhtar, avri.altman, quic_cang, daejun7.park
Cc: linux-scsi, Gwendal Grignou, stable
Prevent a division by 0 when monitoring is not enabled.
Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes")
Cc: stable@vger.kernel.org
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
drivers/ufs/core/ufs-sysfs.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index c95906443d5f9..3692b39b35e78 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -485,6 +485,9 @@ static ssize_t read_req_latency_avg_show(struct device *dev,
struct ufs_hba *hba = dev_get_drvdata(dev);
struct ufs_hba_monitor *m = &hba->monitor;
+ if (!m->nr_req[READ])
+ return sysfs_emit(buf, "0\n");
+
return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]),
m->nr_req[READ]));
}
@@ -552,6 +555,9 @@ static ssize_t write_req_latency_avg_show(struct device *dev,
struct ufs_hba *hba = dev_get_drvdata(dev);
struct ufs_hba_monitor *m = &hba->monitor;
+ if (!m->nr_req[WRITE])
+ return sysfs_emit(buf, "0\n");
+
return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]),
m->nr_req[WRITE]));
}
--
2.47.0.338.g60cca15819-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] scsi: ufs: core: sysfs: Prevent div by zero
2024-11-20 6:25 [PATCH] scsi: ufs: core: sysfs: Prevent div by zero Gwendal Grignou
@ 2024-11-21 20:24 ` Bart Van Assche
2024-11-22 2:12 ` Can Guo
2024-11-22 2:09 ` Can Guo
1 sibling, 1 reply; 5+ messages in thread
From: Bart Van Assche @ 2024-11-21 20:24 UTC (permalink / raw)
To: Gwendal Grignou, alim.akhtar, avri.altman, quic_cang,
daejun7.park
Cc: linux-scsi, stable
On 11/19/24 10:25 PM, Gwendal Grignou wrote:
> Prevent a division by 0 when monitoring is not enabled.
>
> Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes")
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
> drivers/ufs/core/ufs-sysfs.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
> index c95906443d5f9..3692b39b35e78 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -485,6 +485,9 @@ static ssize_t read_req_latency_avg_show(struct device *dev,
> struct ufs_hba *hba = dev_get_drvdata(dev);
> struct ufs_hba_monitor *m = &hba->monitor;
>
> + if (!m->nr_req[READ])
> + return sysfs_emit(buf, "0\n");
> +
> return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]),
> m->nr_req[READ]));
> }
> @@ -552,6 +555,9 @@ static ssize_t write_req_latency_avg_show(struct device *dev,
> struct ufs_hba *hba = dev_get_drvdata(dev);
> struct ufs_hba_monitor *m = &hba->monitor;
>
> + if (!m->nr_req[WRITE])
> + return sysfs_emit(buf, "0\n");
> +
> return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]),
> m->nr_req[WRITE]));
> }
Is anyone using the UFS monitor infrastructure or can it perhaps be
removed?
Thanks,
Bart.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] scsi: ufs: core: sysfs: Prevent div by zero
2024-11-21 20:24 ` Bart Van Assche
@ 2024-11-22 2:12 ` Can Guo
2024-11-25 23:08 ` Bart Van Assche
0 siblings, 1 reply; 5+ messages in thread
From: Can Guo @ 2024-11-22 2:12 UTC (permalink / raw)
To: Bart Van Assche, Gwendal Grignou, alim.akhtar, avri.altman,
daejun7.park
Cc: linux-scsi, stable
Hi Bart,
On 11/22/2024 4:24 AM, Bart Van Assche wrote:
> On 11/19/24 10:25 PM, Gwendal Grignou wrote:
>> Prevent a division by 0 when monitoring is not enabled.
>>
>> Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance
>> monitor sysfs nodes")
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
>> ---
>> drivers/ufs/core/ufs-sysfs.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
>> index c95906443d5f9..3692b39b35e78 100644
>> --- a/drivers/ufs/core/ufs-sysfs.c
>> +++ b/drivers/ufs/core/ufs-sysfs.c
>> @@ -485,6 +485,9 @@ static ssize_t read_req_latency_avg_show(struct
>> device *dev,
>> struct ufs_hba *hba = dev_get_drvdata(dev);
>> struct ufs_hba_monitor *m = &hba->monitor;
>> + if (!m->nr_req[READ])
>> + return sysfs_emit(buf, "0\n");
>> +
>> return sysfs_emit(buf, "%llu\n",
>> div_u64(ktime_to_us(m->lat_sum[READ]),
>> m->nr_req[READ]));
>> }
>> @@ -552,6 +555,9 @@ static ssize_t write_req_latency_avg_show(struct
>> device *dev,
>> struct ufs_hba *hba = dev_get_drvdata(dev);
>> struct ufs_hba_monitor *m = &hba->monitor;
>> + if (!m->nr_req[WRITE])
>> + return sysfs_emit(buf, "0\n");
>> +
>> return sysfs_emit(buf, "%llu\n",
>> div_u64(ktime_to_us(m->lat_sum[WRITE]),
>> m->nr_req[WRITE]));
>> }
>
> Is anyone using the UFS monitor infrastructure or can it perhaps be
> removed?
We are the user of the UFS monitor. And we are about to integrate UFS
queue depth monitoring in it.
Thanks,
Can Guo.
>
> Thanks,
>
> Bart.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] scsi: ufs: core: sysfs: Prevent div by zero
2024-11-22 2:12 ` Can Guo
@ 2024-11-25 23:08 ` Bart Van Assche
0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2024-11-25 23:08 UTC (permalink / raw)
To: Can Guo, Gwendal Grignou, alim.akhtar, avri.altman, daejun7.park
Cc: linux-scsi, stable
On 11/21/24 6:12 PM, Can Guo wrote:
> We are the user of the UFS monitor. And we are about to integrate UFS
> queue depth monitoring in it.
Shouldn't such functionality be integrated in the block layer or SCSI
core instead of in the UFS driver such that this functionality becomes
available to all block drivers?
Thanks,
Bart.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] scsi: ufs: core: sysfs: Prevent div by zero
2024-11-20 6:25 [PATCH] scsi: ufs: core: sysfs: Prevent div by zero Gwendal Grignou
2024-11-21 20:24 ` Bart Van Assche
@ 2024-11-22 2:09 ` Can Guo
1 sibling, 0 replies; 5+ messages in thread
From: Can Guo @ 2024-11-22 2:09 UTC (permalink / raw)
To: Gwendal Grignou, alim.akhtar, avri.altman, daejun7.park
Cc: linux-scsi, stable
On 11/20/2024 2:25 PM, Gwendal Grignou wrote:
> Prevent a division by 0 when monitoring is not enabled.
>
> Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes")
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
> drivers/ufs/core/ufs-sysfs.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
> index c95906443d5f9..3692b39b35e78 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -485,6 +485,9 @@ static ssize_t read_req_latency_avg_show(struct device *dev,
> struct ufs_hba *hba = dev_get_drvdata(dev);
> struct ufs_hba_monitor *m = &hba->monitor;
>
> + if (!m->nr_req[READ])
> + return sysfs_emit(buf, "0\n");
> +
> return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]),
> m->nr_req[READ]));
> }
> @@ -552,6 +555,9 @@ static ssize_t write_req_latency_avg_show(struct device *dev,
> struct ufs_hba *hba = dev_get_drvdata(dev);
> struct ufs_hba_monitor *m = &hba->monitor;
>
> + if (!m->nr_req[WRITE])
> + return sysfs_emit(buf, "0\n");
> +
> return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]),
> m->nr_req[WRITE]));
> }
Thanks for the fix!
Reviewed-by: Can Guo <quic_cang@quicinc.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
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2024-11-20 6:25 [PATCH] scsi: ufs: core: sysfs: Prevent div by zero Gwendal Grignou
2024-11-21 20:24 ` Bart Van Assche
2024-11-22 2:12 ` Can Guo
2024-11-25 23:08 ` Bart Van Assche
2024-11-22 2:09 ` Can Guo
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