iter6: revert depth bump + WRITEBACK_CHUNK_BYTES 32->8 MiB

Browse Source

iter5 (256-frame channel) regressed -1.8 MB/s vs iter4. Reverting to
32 frames.

iter4 sample pattern shows clear ~30 s oscillation (peak 45 MB/s →
dip 3 MB/s → recovery). Matches Linux vm.dirty_expire_centisecs
default (30 s). 32 MiB chunks at 25 MB/s issue WAIT_AFTER every
~1.3 s, which can't outrun the kernel's own page-age limit, so
pages buildup then flush in bursts. Smaller 8 MiB chunks
(WAIT_AFTER every ~0.33 s) should keep the dirty-page set young
and eliminate the periodic flush-burst dip.

...

This commit is contained in:

matthew

2026-05-17 08:09:57 -07:00

parent 940ed8c3b7

commit 05fb2709a5

6 changed files with 12 additions and 11 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download Patch File Download Diff File Expand all files Collapse all files

.claude/worktrees/agent-a1cbe2cec72727536

Submodule

+1

Submodule .claude/worktrees/agent-a1cbe2cec72727536 added at f952bcfce9

.claude/worktrees/agent-a82b8fb113069acd9

Submodule

+1

Submodule .claude/worktrees/agent-a82b8fb113069acd9 added at dcde016bd3

.claude/worktrees/agent-ae58900dbeb230583

Submodule

+1

Submodule .claude/worktrees/agent-ae58900dbeb230583 added at ccf7d97640

.claude/worktrees/agent-aee3289bc097d110f

Submodule

+1

Submodule .claude/worktrees/agent-aee3289bc097d110f added at 0d4879948b