Hi, On 2023-11-17 12:44:41 -0800, Andres Freund wrote: > On 2023-11-07 13:28:28 +0200, Heikki Linnakangas wrote: > > I feel pretty good about this overall. Barring objections or new cfbot > > failures, I will commit this in the next few days. > > I am working on rebasing the AIO patch over this. I think I found a crash > that's unrelated to AIO. > > #4 0x0000000000ea7631 in ExceptionalCondition (conditionName=0x4ba6f1 > "owner->narr == 0", > fileName=0x4ba628 > "../../../../../home/andres/src/postgresql/src/backend/utils/resowner/resowner.c", > lineNumber=354) > at > ../../../../../home/andres/src/postgresql/src/backend/utils/error/assert.c:66 > #5 0x0000000000ef13b5 in ResourceOwnerReleaseAll (owner=0x3367d48, > phase=RESOURCE_RELEASE_BEFORE_LOCKS, printLeakWarnings=false) > at > ../../../../../home/andres/src/postgresql/src/backend/utils/resowner/resowner.c:354 > #6 0x0000000000ef1d9c in ResourceOwnerReleaseInternal (owner=0x3367d48, > phase=RESOURCE_RELEASE_BEFORE_LOCKS, isCommit=false, isTopLevel=true) > at > ../../../../../home/andres/src/postgresql/src/backend/utils/resowner/resowner.c:717 > #7 0x0000000000ef1c89 in ResourceOwnerRelease (owner=0x3367d48, > phase=RESOURCE_RELEASE_BEFORE_LOCKS, isCommit=false, isTopLevel=true) > at > ../../../../../home/andres/src/postgresql/src/backend/utils/resowner/resowner.c:644 > #8 0x00000000008c1f87 in AbortTransaction () at > ../../../../../home/andres/src/postgresql/src/backend/access/transam/xact.c:2851 > #9 0x00000000008c4ae0 in AbortOutOfAnyTransaction () at > ../../../../../home/andres/src/postgresql/src/backend/access/transam/xact.c:4761 > #10 0x0000000000ec1502 in ShutdownPostgres (code=1, arg=0) at > ../../../../../home/andres/src/postgresql/src/backend/utils/init/postinit.c:1357 > #11 0x0000000000c942e5 in shmem_exit (code=1) at > ../../../../../home/andres/src/postgresql/src/backend/storage/ipc/ipc.c:243 > > I think the problem is that ResourceOwnerSort() looks at owner->nhash == 0, > whereas ResourceOwnerReleaseAll() looks at !owner->hash. Therefore it's > possible to reach ResourceOwnerReleaseAll() with owner->hash != NULL while > also having owner->narr > 0. > > I think both checks for !owner->hash in ResourceOwnerReleaseAll() need to > instead check owner->nhash == 0. > > I'm somewhat surprised that this is only hit with the AIO branch. I guess one > needs to be somewhat unlucky to end up with a hashtable but 0 elements in it > at the time of resowner release. But still somewhat surprising.
Oops - I hadn't rebased far enough at this point... That was already fixed in 8f4a1ab471e. Seems like it'd be good to cover that path in one of the tests? - Andres
