Feature #14705: [PATCH] eval.c (ruby_setup): disable THP on Linux

• Status: Closed
• Assignee: -
• Target version: -

[normalperson (Eric Wong)]

Transparent Huge Pages (THP) decrease the effectiveness of
CoW-friendly GC because it decreases page granularity. That is,
a forked process dirtying one bit of CoW-shared memory can
trigger a copy of a huge page (2MB on x86-64) instead of a smaller,
standard page (4K).

I think this is fairly obvious choice to make since we already
decide to support bitmap marking GC for CoW-friendliness.
Will commit in a few days if no response.

[normalperson (Eric Wong)]

• Status changed from Open to Closed

Applied in changeset trunk|r63253.

---

eval.c (ruby_setup): disable THP on Linux

Transparent Huge Pages (THP) decrease the effectiveness of
CoW-friendly GC because it decreases page granularity. That is,
a forked process dirtying one bit of CoW-shared memory can
trigger a copy of a huge page (2MB on x86-64) instead of a smaller,
standard page (4K).

• eval.c (ruby_setup): disable THP on Linux
  [ruby-core:86651] [Feature #14705]