Re: [HACKERS] Open 6.5 items

Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> writes:
> Folks, do we have anything to revisit here?

I believe it is fixed --- I went back and found some more bugs in
dynahash.c after seeing Tatsuo's report ;-)

regards, tom lane

>> Tatsuo Ishii wrote:
>>>>
>>>> I have just done cvs update and saw your changes. I tried the same
>>>> testing as I did before (64 conccurrent connections, and each
>>>> connection excutes 100 transactions), but it failed again.
>>>>
>>>> (1) without -B 1024, it failed: out of free buffers: time to abort!
>>>>
>>>> (2) with -B 1024, it went into stuck spin lock
>>>>
>>>> So I looked into sources a little bit, and made a minor change to
>>>> include/storage/lock.h:
>>>>
>>>> #define INIT_TABLE_SIZE 100
>>>>
>>>> to:
>>>>
>>>> #define INIT_TABLE_SIZE 4096
>>>>
>>>> then restarted postmaster with -B 1024 (this will prevent
>>>> out-of-free-buffers problem, I guess). Now everything seems to work
>>>> great!
>>>>
>>>> I suspect that huge INIT_TABLE_SIZE prevented dynamic expanding the
>>>> hash tables and seems there's something wrong in the routines
>>>> responsible for that.
>>
>> Seems like that -:(
>>
>> If we'll not fix expand hash code before 6.5 release then
>> I would recommend to don't use INIT_TABLE_SIZE in
>>
lockMethodTable-> lockHash = (HTAB *) ShmemInitHash(shmemName,
>> INIT_TABLE_SIZE, MAX_TABLE_SIZE,
>> &info, hash_flags);
>>
>> and
>>
lockMethodTable-> xidHash = (HTAB *) ShmemInitHash(shmemName,
>> INIT_TABLE_SIZE, MAX_TABLE_SIZE,
>> &info, hash_flags);
>>
>> but use NLOCKENTS(maxBackends) instead.
>>
>> Vadim