On 28/03/2026 00:05, Nathan Bossart wrote:
On Fri, Mar 27, 2026 at 04:50:12PM -0500, Nathan Bossart wrote:
On Fri, Mar 27, 2026 at 05:22:33PM -0400, Andres Freund wrote:
TRAP: failed Assert("MemoryContextIsValid(context)"), File: "mcxt.c", Line:
1270, PID: 230491
[...](ExceptionalCondition+0x54)[0xaaaae186c204]
[...](MemoryContextAllocExtended+0x0)[0xaaaae18a2a24]
[...](RequestNamedLWLockTranche+0x6c)[0xaaaae16e7310]
[...](process_shmem_requests+0x28)[0xaaaae1881628]
[...](PostgresSingleUserMain+0xc4)[0xaaaae1701a34]
[...](main+0x6ac)[0xaaaae12a2adc]
/lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe8)[0xffff99713dd8]
[...](+0xf2b98)[0xaaaae12a2b98]
Aborted
pg_rewind: error: postgres single-user mode in target cluster failed
Hm. AFAICT PostmasterContext isn't created in single-user mode, and the
commit in question has RequestNamedLWLockTranche() allocate requests there.
I guess the idea is to allow backends to free that memory after forking
from postmaster, but we don't do that for the NamedLWLockTrancheRequests
list. Maybe we should surround the last part of that function with
MemoryContextSwitchTo(...) to either TopMemoryContext or PostmasterContext
depending on whether we're in single-user mode.
Concretely, like the attached.
LGTM, thanks! Will you commit or want me to pick it up?
- Heikki
