15.10.2020 20:16, Andrey Shinkevich wrote:
On 14.10.2020 19:24, Max Reitz wrote:
On 12.10.20 19:43, Andrey Shinkevich wrote:
[...]
---
block/stream.c | 93 +++++++++++++++++++++++++++++-----------------
tests/qemu-iotests/030 | 51 +++----------------------
tests/qemu-iotests/030.out | 4 +-
tests/qemu-iotests/141.out | 2 +-
tests/qemu-iotests/245 | 19 +++++++---
5 files changed, 81 insertions(+), 88 deletions(-)
Looks like stream_run() could be a bit streamlined now (the allocation
checking should be unnecessary, unconditionally calling
stream_populate() should be sufficient), but not necessary now.
That is what I had kept in my mind when I tackled this patch. But there is an underwater reef to streamline. Namely, how the block-stream job gets known about a long unallocated tail to exit the loop earlier in the stream_run(). Shall we return the '-EOF' or another error code from the cor_co_preadv_part() to be handled by the stream_run()? Any other suggestions, if any, will be appreciated.
Just calling read CHUNK by CHUNK may be less efficient than is_allocated()-driven loop: you may end up with splitting regions unaligned to CHUNK-granularity, which would not be splitted with is_allocated()-driven loop. Current loop allows chunks unaligned to CHUNK.
So, I think, it's better to keep is_allocated() logic as is for now.
--
Best regards,
Vladimir
