ping-2
On 18/9/2018 11:12 AM, Anton Nefedov wrote: > ping > > do you think we might proceed with this? or is there any general doubt > about the idea? > > thanks, > > On 21/8/2018 12:46 PM, Anton Nefedov wrote: >> new in v4: >> - patch 7: discard and write-zeroes code paths had been separated in >> 34fa110e: file-posix: Fix write_zeroes with unmap on block >> devices. >> This patch now only accounts discards that come explicitly >> through .bdrv_co_pdiscard handler. >> - qapi 'Since' clauses changed 3.0 -> 3.1 >> >> 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 1-6 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 8). >> With patch 7, 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) >> >> { >> "return": [ >> { >> "device": "drive-scsi0-0-0-0", >> "parent": { >>> "discard-bytes-ok": 262144, >>> "discard-nb-ok": 4, >> "stats": { >>> "unmap_operations": 0, >>> "unmap_merged": 0, >> "flush_total_time_ns": 0, >> "wr_highest_offset": 8111718400, >> "wr_total_time_ns": 0, >> "failed_wr_operations": 0, >> "failed_rd_operations": 0, >> "wr_merged": 0, >> "wr_bytes": 0, >> "timed_stats": [ >> ], >>> "failed_unmap_operations": 0, >> "failed_flush_operations": 0, >> "account_invalid": false, >> "rd_total_time_ns": 0, >>> "invalid_unmap_operations": 0, >> "flush_operations": 0, >> "wr_operations": 0, >>> "unmap_bytes": 0, >> "rd_merged": 0, >> "rd_bytes": 0, >>> "unmap_total_time_ns": 0, >> "invalid_flush_operations": 0, >> "account_failed": false, >> "rd_operations": 0, >> "invalid_wr_operations": 0, >> "invalid_rd_operations": 0 >> }, >> "node-name": "#block012", >>> "driver": "file", >>> "discard-nb-failed": 0 >> }, >> "stats": { >>> "unmap_operations": 860, >>> "unmap_merged": 0, >> "flush_total_time_ns": 21506733, >> "wr_highest_offset": 13411741696, >> "wr_total_time_ns": 2212749334, >> "failed_wr_operations": 0, >> "failed_rd_operations": 0, >> "wr_merged": 0, >> "wr_bytes": 3426304, >> "timed_stats": [ >> ], >>> "failed_unmap_operations": 0, >> "failed_flush_operations": 0, >> "account_invalid": true, >> "rd_total_time_ns": 3617478206, >>> "invalid_unmap_operations": 0, >> "flush_operations": 24, >> "wr_operations": 309, >>> "unmap_bytes": 11949633536, >> "rd_merged": 0, >> "rd_bytes": 141967360, >>> "unmap_total_time_ns": 14871816, >> [..] >> >> Anton Nefedov (8): >> qapi: group BlockDeviceStats fields >> qapi: add unmap to BlockDeviceStats >> 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 | 82 >> +++++++++++++++++++++++++++++++++++++++------- >> include/block/accounting.h | 1 + >> include/block/block.h | 1 + >> include/block/block_int.h | 1 + >> block.c | 9 +++++ >> block/file-posix.c | 45 +++++++++++++++++++++++-- >> block/qapi.c | 11 +++++++ >> hw/ide/core.c | 12 +++++++ >> hw/scsi/scsi-disk.c | 29 +++++++++------- >> tests/qemu-iotests/227.out | 18 ++++++++++ >> 10 files changed, 184 insertions(+), 25 deletions(-) >>