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

ExtentWalker: increase efficiency for typical btrfs extent sizes

Browse Source 
Perf was blaming more than 50% of cycles on TREE_SEARCH_V2.  strace
showed 4 TREE_SEARCH_V2 calls for every pread in grow_backward().

Fix by increasing the extent fetch batch size so it is more likely
to include the desired items in the first fetch attempt.

This removes TREE_SEARCH_V2 from the top 10 list of cycle consumers.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>
This commit is contained in:
Zygo Blaxell 2018-01-28 01:37:21 -05:00
parent e74c0a9d80
commit 72cc9c2b60
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/crucible/extentwalker.h
View File

@ -58,7 +58,7 @@ namespace crucible {
virtual Vec get_extent_map(off_t pos);
static const unsigned sc_extent_fetch_max = 64;
static const unsigned sc_extent_fetch_max = 1024;
static const unsigned sc_extent_fetch_min = 4;
static const off_t sc_step_size = 0x1000 * (sc_extent_fetch_max / 2);