[Qemu-devel] [PATCH v9 0/9] discard blockstats

Anton Nefedov posted 9 patches 4 years, 6 months ago
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git fetch https://github.com/patchew-project/qemu tags/patchew/20190906160120.70239-1-anton.nefedov@virtuozzo.com
Maintainers: Kevin Wolf <kwolf@redhat.com>, John Snow <jsnow@redhat.com>, Fam Zheng <fam@euphon.net>, Max Reitz <mreitz@redhat.com>, Eric Blake <eblake@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Markus Armbruster <armbru@redhat.com>
There is a newer version of this series
qapi/block-core.json       | 81 ++++++++++++++++++++++++++++++++------
include/block/accounting.h |  2 +
include/block/block.h      |  1 +
include/block/block_int.h  |  1 +
block.c                    |  9 +++++
block/accounting.c         |  6 +++
block/file-posix.c         | 54 ++++++++++++++++++++++++-
block/qapi.c               | 11 ++++++
hw/ide/core.c              | 12 ++++++
hw/scsi/scsi-disk.c        | 34 ++++++++++------
tests/qemu-iotests/227.out | 18 +++++++++
11 files changed, 206 insertions(+), 23 deletions(-)
[Qemu-devel] [PATCH v9 0/9] discard blockstats
Posted by Anton Nefedov 4 years, 6 months ago
v9:
 - fixed patch 5 so the fields are actually numbered in sectors not blocks
 - fixed patch 7 accordingly
 - patch 8: make stat fields unsigned
 - qapi patches: "since 4.1" -> "since 4.2"

v8: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03709.html

----

qmp query-blockstats provides stats info for write/read/flush ops.

Patches 1-7 implement the similar for discard (unmap) command for scsi
and ide disks.
Discard stat "unmap_ops / unmap_bytes" is supposed to account the ops that
have completed without an error.

However, discard operation is advisory. Specifically,
 - common block layer ignores ENOTSUP error code.
   That might be returned if the block driver does not support discard,
   or discard has been configured to be ignored.
 - format drivers such as qcow2 may ignore discard if they were configured
   to ignore that, or if the corresponding area is already marked unused
   (unallocated / zero clusters).

And what is actually useful is the number of bytes actually discarded
down on the host filesystem.
To achieve that, driver-specific statistics has been added to blockstats
(patch 9).
With patch 8, file-posix driver accounts discard operations on its level too.

query-blockstat result:

(note the difference between blockdevice unmap and file discard stats. qcow2
sends fewer ops down to the file as the clusters are actually unallocated
on qcow2 level)

    {
      "device": "drive-scsi0-0-0-0",
      "node-name": "#block159",
      "stats": {
>       "invalid_unmap_operations": 0,
>       "failed_unmap_operations": 0,
        "wr_highest_offset": 13411688448,
        "rd_total_time_ns": 2859566315,
        "rd_bytes": 103182336,
        "rd_merged": 0,
        "flush_operations": 19,
        "invalid_wr_operations": 0,
        "flush_total_time_ns": 23111608,
        "failed_rd_operations": 0,
        "failed_flush_operations": 0,
        "invalid_flush_operations": 0,
        "timed_stats": [
          
        ],
        "wr_merged": 0,
        "wr_bytes": 1702912,
>       "unmap_bytes": 11954954240,
>       "unmap_operations": 865,
        "idle_time_ns": 2669508623,
        "account_invalid": true,
>       "unmap_total_time_ns": 19698002,
        "wr_operations": 143,
        "failed_wr_operations": 0,
        "rd_operations": 4816,
        "account_failed": true,
>       "unmap_merged": 0,
        "wr_total_time_ns": 1262686124,
        "invalid_rd_operations": 0
      },
      "parent": {
>       "driver-specific": {
>         "discard-nb-failed": 0,
>         "discard-bytes-ok": 720896,
>         "driver": "file",
>         "discard-nb-ok": 8
>       },
        "node-name": "#block009",
        "stats": {
        [..]
        }
      }
    },
    {
      "device": "floppy0",

Anton Nefedov (9):
  qapi: group BlockDeviceStats fields
  qapi: add unmap to BlockDeviceStats
  block: add empty account cookie type
  ide: account UNMAP (TRIM) operations
  scsi: store unmap offset and nb_sectors in request struct
  scsi: move unmap error checking to the complete callback
  scsi: account unmap operations
  file-posix: account discard operations
  qapi: query-blockstat: add driver specific file-posix stats

 qapi/block-core.json       | 81 ++++++++++++++++++++++++++++++++------
 include/block/accounting.h |  2 +
 include/block/block.h      |  1 +
 include/block/block_int.h  |  1 +
 block.c                    |  9 +++++
 block/accounting.c         |  6 +++
 block/file-posix.c         | 54 ++++++++++++++++++++++++-
 block/qapi.c               | 11 ++++++
 hw/ide/core.c              | 12 ++++++
 hw/scsi/scsi-disk.c        | 34 ++++++++++------
 tests/qemu-iotests/227.out | 18 +++++++++
 11 files changed, 206 insertions(+), 23 deletions(-)

-- 
2.17.1


Re: [PATCH v9 0/9] discard blockstats
Posted by Max Reitz 4 years, 6 months ago
On 06.09.19 18:01, Anton Nefedov wrote:
> v9:
>  - fixed patch 5 so the fields are actually numbered in sectors not blocks
>  - fixed patch 7 accordingly
>  - patch 8: make stat fields unsigned
>  - qapi patches: "since 4.1" -> "since 4.2"
> 
> v8: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03709.html

For the record: Looks OK to me, but I suppose you still wanted to change
patch 3’s commit message.

(I still don’t like patch 9 very much, but that won’t stop me from
taking it.)

Max

Re: [PATCH v9 0/9] discard blockstats
Posted by Anton Nefedov 4 years, 6 months ago
On 23/9/2019 1:59 PM, Max Reitz wrote:
> On 06.09.19 18:01, Anton Nefedov wrote:
>> v9:
>>   - fixed patch 5 so the fields are actually numbered in sectors not blocks
>>   - fixed patch 7 accordingly
>>   - patch 8: make stat fields unsigned
>>   - qapi patches: "since 4.1" -> "since 4.2"
>>
>> v8: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03709.html
> 
> For the record: Looks OK to me, but I suppose you still wanted to change
> patch 3’s commit message.
> 
> (I still don’t like patch 9 very much, but that won’t stop me from
> taking it.)
> 

hi,
I've now resent the series with the updated patch 3 commit message

https://lists.nongnu.org/archive/html/qemu-devel/2019-09/msg05050.html

thanks,