| Message ID | 20181130144705.77454-1-anton.nefedov@virtuozzo.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | discard blockstats | expand |
On 30/11/2018 5:47 PM, Anton Nefedov wrote: > 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. > ping
On 14/1/2019 4:16 PM, Anton Nefedov wrote: > On 30/11/2018 5:47 PM, Anton Nefedov wrote: >> 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. >> > > ping ping
new in v6: - since clauses -> 4.0 - patch 9: qapi json cosmetic changes as suggested by Vladimir - patch 9: proper "driver" field setting for host_device driver v5: http://lists.nongnu.org/archive/html/qemu-devel/2018-10/msg06828.html v4: http://lists.nongnu.org/archive/html/qemu-devel/2018-08/msg04308.html v3: http://lists.nongnu.org/archive/html/qemu-devel/2018-06/msg03688.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 | 60 ++++++++++++++++++++++++++-- block/qapi.c | 11 ++++++ hw/ide/core.c | 12 ++++++ hw/scsi/scsi-disk.c | 32 +++++++++------ tests/qemu-iotests/227.out | 18 +++++++++ 11 files changed, 208 insertions(+), 25 deletions(-)