2022-02-14 09:47:12

by Chengming Zhou

Subject: [PATCH] blk-cgroup: set blkg iostat after percpu stat aggregation

Don't need to do blkg_iostat_set for top blkg iostat on each CPU,
so move it after percpu stat aggregation.

Fixes: ef45fe470e1e ("blk-cgroup: show global disk stats in root cgroup
io.stat")
Signed-off-by: Chengming Zhou <[email protected]>
---
block/blk-cgroup.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 650f7e27989f..87a1c0c3fa40 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -857,11 +857,11 @@ static void blkcg_fill_root_iostats(void)
blk_queue_root_blkg(bdev_get_queue(bdev));
struct blkg_iostat tmp;
int cpu;
+ unsigned long flags;

memset(&tmp, 0, sizeof(tmp));
for_each_possible_cpu(cpu) {
struct disk_stats *cpu_dkstats;
- unsigned long flags;

cpu_dkstats = per_cpu_ptr(bdev->bd_stats, cpu);
tmp.ios[BLKG_IOSTAT_READ] +=
@@ -877,11 +877,11 @@ static void blkcg_fill_root_iostats(void)
cpu_dkstats->sectors[STAT_WRITE] << 9;
tmp.bytes[BLKG_IOSTAT_DISCARD] +=
cpu_dkstats->sectors[STAT_DISCARD] << 9;
-
- flags = u64_stats_update_begin_irqsave(&blkg->iostat.sync);
- blkg_iostat_set(&blkg->iostat.cur, &tmp);
- u64_stats_update_end_irqrestore(&blkg->iostat.sync, flags);
}
+
+ flags = u64_stats_update_begin_irqsave(&blkg->iostat.sync);
+ blkg_iostat_set(&blkg->iostat.cur, &tmp);
+ u64_stats_update_end_irqrestore(&blkg->iostat.sync, flags);
}
}

--
2.20.1

2022-02-14 21:19:51

by Tejun Heo

Subject: Re: [PATCH] blk-cgroup: set blkg iostat after percpu stat aggregation

On Sun, Feb 13, 2022 at 04:59:02PM +0800, Chengming Zhou wrote:
> Don't need to do blkg_iostat_set for top blkg iostat on each CPU,
> so move it after percpu stat aggregation.
>
> Fixes: ef45fe470e1e ("blk-cgroup: show global disk stats in root cgroup
> io.stat")

I'm not sure Fixes tag is necessary here.

> Signed-off-by: Chengming Zhou <[email protected]>

but other than that,

Acked-by: Tejun Heo <[email protected]>

Thanks.

--
tejun

2022-02-16 00:54:57

by Chengming Zhou

Subject: Re: [Phishing Risk] [External] Re: [PATCH] blk-cgroup: set blkg iostat after percpu stat aggregation

On 2022/2/15 2:59 上午, Tejun Heo wrote:
> On Sun, Feb 13, 2022 at 04:59:02PM +0800, Chengming Zhou wrote:
>> Don't need to do blkg_iostat_set for top blkg iostat on each CPU,
>> so move it after percpu stat aggregation.
>>
>> Fixes: ef45fe470e1e ("blk-cgroup: show global disk stats in root cgroup
>> io.stat")
>
> I'm not sure Fixes tag is necessary here.

I'm also not sure, since the io.stat reports correct data after all. I put
the Fixes tag here in case someone wants it. Please feel free to delete it.

Thanks.

>
>> Signed-off-by: Chengming Zhou <[email protected]>
>
> but other than that,
>
> Acked-by: Tejun Heo <[email protected]>
>
> Thanks.
>

2022-02-16 06:56:30

by Jens Axboe

Subject: Re: [PATCH] blk-cgroup: set blkg iostat after percpu stat aggregation

On Sun, 13 Feb 2022 16:59:02 +0800, Chengming Zhou wrote:
> Don't need to do blkg_iostat_set for top blkg iostat on each CPU,
> so move it after percpu stat aggregation.
>
>

Applied, thanks!

[1/1] blk-cgroup: set blkg iostat after percpu stat aggregation
commit: f122d103b564e5fb7c82de902c6f8f6cbdf50ec9

Best regards,
--
Jens Axboe