GGLinnk/bees
1
0
Fork 0
mirror of https://github.com/Zygo/bees.git synced 2025-05-17 21:35:45 +02:00
Code Packages

README: upgrade kernel requirement to 4.4.3 because of kernel bugs

Browse Source
This commit is contained in:
Zygo Blaxell 2016-12-07 22:01:45 -05:00
parent 1cd6263552
commit d82909387d
1 changed files with 14 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
README.md
View File

@ -223,20 +223,25 @@ Other Caveats
A Brief List Of Btrfs Kernel Bugs A Brief List Of Btrfs Kernel Bugs
--------------------------------- ---------------------------------
Fixed bugs: Missing features (usually not available in older LTS kernels):
* 3.13: `FILE_EXTENT_SAME` ioctl added. No way to reliably dedup with * 3.13: `FILE_EXTENT_SAME` ioctl added. No way to reliably dedup with
concurrent modifications before this. concurrent modifications before this.
* 3.16: `SEARCH_V2` ioctl added. Bees could use `SEARCH` instead. * 3.16: `SEARCH_V2` ioctl added. Bees could use `SEARCH` instead.
* 4.2: `FILE_EXTENT_SAME` no longer updates mtime, can be used at EOF. * 4.2: `FILE_EXTENT_SAME` no longer updates mtime, can be used at EOF.
Kernel deadlock bugs fixed.
Bug fixes (sometimes included in older LTS kernels):
* 4.5: hang in the `INO_PATHS` ioctl used by Bees.
* 4.5: use-after-free in the `FILE_EXTENT_SAME` ioctl used by Bees.
* 4.7: *slow backref* bug no longer triggers a softlockup panic. It still * 4.7: *slow backref* bug no longer triggers a softlockup panic. It still
too long to resolve a block address to a root/inode/offset triple. too long to resolve a block address to a root/inode/offset triple.
Fixed bugs not yet integrated in mainline Linux: Fixed bugs not yet integrated in mainline Linux:
* 7f8e406 ("btrfs: improve delayed refs iterations"): reduces the cost * 7f8e406 ("btrfs: improve delayed refs iterations"): significantly
of LOGICAL_INO ioctl from 30-70% of bees running time to under 5%. reduces the CPU time cost of the LOGICAL_INO ioctl (from 30-70% of
bees running time to under 5%).
Unfixed kernel bugs (as of 4.5.7) with workarounds in Bees: Unfixed kernel bugs (as of 4.5.7) with workarounds in Bees:
@ -282,8 +287,10 @@ Unfixed kernel bugs (as of 4.5.7) with workarounds in Bees:
the filesystem after a crash). Alternatively, place BEESHOME on a the filesystem after a crash). Alternatively, place BEESHOME on a
non-btrfs filesystem. non-btrfs filesystem.
* If the fsync() BeesTempFile::make_copy is removed, the filesystem * If the `fsync()` in `BeesTempFile::make_copy` is removed, the filesystem
hangs within a few hours, requiring a reboot to recover. hangs within a few hours, requiring a reboot to recover. On the other
hand, there may be net performance benefits to calling `fsync()` before
or after each dedup. This needs further investigation.
Not really a bug, but a gotcha nonetheless: Not really a bug, but a gotcha nonetheless:
@ -314,7 +321,7 @@ Requirements
TODO: remove the one function used from this library. TODO: remove the one function used from this library.
It supports a feature Bees no longer implements. It supports a feature Bees no longer implements.
* Linux kernel 4.2 or later * Linux kernel 4.4.3 or later
Don't bother trying to make Bees work with older kernels. Don't bother trying to make Bees work with older kernels.
It won't end well. It won't end well.