On December 21, 2024 6:50 AM, Patrick Steinhardt wrote:

this small patch series fixes out-of-memory errors on NonStop with the reftable
backend. These errors are caused by zero-sized allocations, which return `NULL`
pointers on NonStop.

Thanks!

Patrick

---
Patrick Steinhardt (4):
     reftable/stack: don't perform auto-compaction with less than two tables
     reftable/merged: fix zero-sized allocation when there are no readers
     reftable/stack: fix zero-sized allocation when there are no readers
     reftable/basics: return NULL on zero-sized allocations

reftable/basics.c |  7 +++++++
reftable/merged.c | 12 +++++++-----
reftable/stack.c  | 47 ++++++++++++++++++++++++++---------------------
3 files changed, 40 insertions(+), 26 deletions(-)


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base-commit: ff795a5c5ed2e2d07c688c217a615d89e3f5733b
change-id: 20241220-b4-pks-reftable-oom-fix-without-readers-c7d8fda0694d

From the malloc man page:
"If size is 0, then malloc() returns either NULL, or a unique pointer value that can later be successfully passed to free()."

Thank you for this series. I think the problem may not be limited only to NonStop based on the documented ambiguous behaviour of malloc.

--Randall