Re: [PATCH 3/4] block/copy-before-write: reverse access bitmap

2025-05-21 Thread Andrey Zhadchenko
On 5/20/25 19:26, Eric Blake wrote: [?? ??? ? ?? ?? ebl...@redhat.com. ???, ?? ??? ?, ?? ?? https://aka.ms/LearnAboutSenderIdentification ] On Tue, May 13, 2025 at 03:32:37AM +0200, Andrey Zhadchenko wrote: HBitmaps allow us to search set bits pretty fast. On

Re: [PATCH 3/4] block/copy-before-write: reverse access bitmap

2025-05-20 Thread Eric Blake
On Tue, May 13, 2025 at 03:32:37AM +0200, Andrey Zhadchenko wrote: > HBitmaps allow us to search set bits pretty fast. On the contrary, > when searching zeroes, we may be forced to fully traverse the lower > level. > When we run blockdev-backup with mode=full on top of snapshot filter > + cbw filte

[PATCH 3/4] block/copy-before-write: reverse access bitmap

2025-05-12 Thread Andrey Zhadchenko
HBitmaps allow us to search set bits pretty fast. On the contrary, when searching zeroes, we may be forced to fully traverse the lower level. When we run blockdev-backup with mode=full on top of snapshot filter + cbw filter, the job fills copy bitmap by calling block_status() with range (X, virtual