SUNDAY, APRIL 19, 2026 GLIBC DIGEST · OPEN-SOURCE SYSTEMS DAILY VOL. 1 · NO. 109
Late Edition · APRIL 19, 2026 · VOL. 1 · NO. 109
The glibc Digest
— A Daily Record of the GNU C Library —
glibc Proposed

Add system-wide tunables

This series introduces system-wide tunables configurable via /etc/tunables.conf, allowing administrators to adjust glibc behavior per-process.

This patch series implements system-wide tunables for glibc. It reads tunable configurations from /etc/tunables.conf using ldconfig, stores them in /etc/ld.so.cache, and applies them to running applications. The configuration supports per-process overrides. This is version 7 of the patch.

Technical Tradeoffs

  • Reuses ldconfig for reading the configuration, which avoids introducing new tooling but may constrain the design.
  • Adds complexity to ld.so.cache loading.
  • Introduces a new configuration file format.
  • Requires careful validation of tunable values to prevent unexpected behavior.
Filed Under: tunablesconfigurationldconfigperformance