2020-03-25 13:10:19

by Konstantin Khlebnikov

Subject: [PATCH v4 0/3] block/diskstats: more accurate io_ticks and optimization

Simplified estimation for io_ticks introduced in patch
https://lore.kernel.org/linux-block/[email protected]/
could be very inaccurate for request longer than jiffy (i.e. any HDD)

There is at least one another report about this:
https://lore.kernel.org/linux-block/[email protected]/
See detail in comment for first patch.

v1: https://lore.kernel.org/lkml/155413438394.3201.15211440151043943989.stgit@buzz/
v2: https://lore.kernel.org/lkml/158314549775.1788.6529015932237292177.stgit@buzz/
v3: https://lore.kernel.org/lkml/158503038812.1955.7827988255138056389.stgit@buzz/
* update documentation
* rebase to current linux-next
* fix compilation for CONFIG_SMP=n
v4:
* rebase to for-5.7/block
* make part_stat_read_all static in block/genhd.c

---

Konstantin Khlebnikov (3):
block/diskstats: more accurate approximation of io_ticks for slow disks
block/diskstats: accumulate all per-cpu counters in one pass
block/diskstats: replace time_in_queue with sum of request times


Documentation/admin-guide/iostats.rst | 5 +-
block/bio.c | 9 +--
block/blk-core.c | 5 +-
block/genhd.c | 109 +++++++++++++++++++++++----------
include/linux/genhd.h | 6 --
5 files changed, 88 insertions(+), 46 deletions(-)

--
Signature

2020-03-25 14:50:30

by Jens Axboe

Subject: Re: [PATCH v4 0/3] block/diskstats: more accurate io_ticks and optimization

On 3/25/20 7:07 AM, Konstantin Khlebnikov wrote:
> Simplified estimation for io_ticks introduced in patch
> https://lore.kernel.org/linux-block/[email protected]/
> could be very inaccurate for request longer than jiffy (i.e. any HDD)
>
> There is at least one another report about this:
> https://lore.kernel.org/linux-block/[email protected]/
> See detail in comment for first patch.
>
> v1: https://lore.kernel.org/lkml/155413438394.3201.15211440151043943989.stgit@buzz/
> v2: https://lore.kernel.org/lkml/158314549775.1788.6529015932237292177.stgit@buzz/
> v3: https://lore.kernel.org/lkml/158503038812.1955.7827988255138056389.stgit@buzz/
> * update documentation
> * rebase to current linux-next
> * fix compilation for CONFIG_SMP=n
> v4:
> * rebase to for-5.7/block
> * make part_stat_read_all static in block/genhd.c

Applied for 5.7, thanks.

--
Jens Axboe