Bug 16490 - glibc 2.43 allocates much more memory than glibc 2.39
Summary: glibc 2.43 allocates much more memory than glibc 2.39
Status: NEW
Alias: None
Product: OE-Core
Classification: Build System, Metadata & Runtime
Component: core (show other bugs)
Version: 6.0.3
Hardware: ARM arm64
: Undecided major
Target Milestone: 0.0.0
Assignee: Unassigned
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Reported: 2026-11-05 12:48 UTC by Etienne Cordonnier
Modified: 2026-11-05 12:48 UTC (History)
2 users (show)

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OS type for building Yocto: ---
Type of Regression: ---
Verified:
Documentation change: No (bug/feature does not impact docs)

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Description Etienne Cordonnier 2026-11-05 12:48:37 UTC 
We noticed this critical regression while updating from scarthgap 5.0.20 to wrynose 6.0.3:

glibc 2.43 malloc allocations on aarch64 are massively bigger than on glibc 2.39. We have reported findings at https://sourceware.org/bugzilla/show_bug.cgi?id=34081 which is the upstream bug.

We compared the same image based on scarthgap 5.0.20 with only glibc changed. These are system-wide readings from one cold boot per configuration, averaged
over 55-180 s after boot at idle:

                          2.39     2.43
  AnonPages (MiB)          465     1105
  AnonHugePages (MiB)        0      743
  MemAvailable (MiB)      1850     1214
  Swap-out since boot (MiB)  0      385