Re: TRAP: FailedAssertion("!((itemid)->lp_flags & 0x01)",

[Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>]

Jim C. Nasby wrote:
> Here's another core... (pid 805 for reference)

All of them have in common that the slotno being passed ($3 below) is in
SLRU_PAGE_READ_IN_PROGRESS state ... could it be a problem with lock
reordering?  Maybe somebody is trying to read in a page, and somebody
else steals the buffer from under them.  Not sure how likely is that.

BTW what's the relationship with the other assertion failure (the one in
the subject)?

> #3  0x000000000047365f in SimpleLruReadPage (ctl=0x7d9f40, pageno=169039, xid=0) at slru.c:307
> 307                     Assert(shared->page_number[slotno] == pageno &&
> 
> $1 = {ControlLock = SubtransControlLock, page_buffer = {0x2a98298380 "", 0x2a9829a380 "",
>     0x2a9829c380 "", 0x2a9829e380 "", 0x2a982a0380 "", 0x2a982a2380 "", 0x2a982a4380 "",
>     0x2a982a6380 ""}, page_status = {SLRU_PAGE_DIRTY, SLRU_PAGE_CLEAN,
>     SLRU_PAGE_READ_IN_PROGRESS, SLRU_PAGE_CLEAN, SLRU_PAGE_CLEAN, SLRU_PAGE_READ_IN_PROGRESS,
>     SLRU_PAGE_CLEAN, SLRU_PAGE_CLEAN}, page_number = {169452, 169351, 169163, 169238, 169236,
>     169328, 169233, 169239}, page_lru_count = {17108, 4, 1, 3, 5, 0, 6, 2}, buffer_locks = {
>     24, 25, 26, 27, 28, 29, 30, 31}, latest_page_number = 169452}
> $2 = 169039
> $3 = 2
> $4 = 1 '\001'
> $5 = 0


-- 
Alvaro Herrera       Valdivia, Chile   ICBM: S 39º 49' 17.7", W 73º 14' 26.8"
"Nadie esta tan esclavizado como el que se cree libre no siendolo" (Goethe)