Hi Tom,
On Mon, 8 Dec 2008, Tom Lane wrote:
Date: Mon, 08 Dec 2008 13:15:28 -0500
From: Tom Lane <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Cc: Heikki Linnakangas <[EMAIL PROTECTED]>,
Zdenek Kotala <[EMAIL PROTECTED]>,
pgsql-hackers list <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] cvs head initdb hangs on unixware
[EMAIL PROTECTED] writes:
the infinite loop occurs in fsm_search_avail when called for the 32nd
time.
... which is the first time that the initial test doesn't make it fall
out immediately.
Would you add a couple more printouts, along the line of
nodeno = target;
while (nodeno > 0)
{
+ fprintf(stderr, "ascend at node %d value %d\n",
+ nodeno, fsmpage->fp_nodes[nodeno]);
if (fsmpage->fp_nodes[nodeno] >= minvalue)
break;
/*
* Move to the right, wrapping around on same level if
necessary,
* then climb up.
*/
nodeno = parentof(rightneighbor(nodeno));
}
/*
* We're now at a node with enough free space, somewhere in the middle
of
* the tree. Descend to the bottom, following a path with enough free
* space, preferring to move left if there's a choice.
*/
while (nodeno < NonLeafNodesPerPage)
{
int leftnodeno = leftchild(nodeno);
int rightnodeno = leftnodeno + 1;
bool leftok = (leftnodeno < NodesPerPage) &&
(fsmpage->fp_nodes[leftnodeno] >= minvalue);
bool rightok = (rightnodeno < NodesPerPage) &&
(fsmpage->fp_nodes[rightnodeno] >= minvalue);
+ fprintf(stderr, "descend at node %d value %d, leftnode %d value %d,
rightnode %d value %d\n",
+ nodeno, fsmpage->fp_nodes[nodeno],
+ leftnodeno, fsmpage->fp_nodes[leftnodeno],
+ rightnodeno, fsmpage->fp_nodes[rightnodeno]);
if (leftok)
nodeno = leftnodeno;
else if (rightok)
nodeno = rightnodeno;
else
(I'm assuming we can print possibly-off-the-end array elements without dumping
core; which is bogus in general but I expect we can get away with it
for this purpose.)
Also, we don't really need 94MB of log to convince us it's an
infinite loop ;-)
oops, sorry
regards, tom lane
I first misread your mail, and added only the first fprintf , while I was
uploading a 400M initdb.log, I went back to add the second one.
Guess what! with the fprintf .. descending node... in place, everything
goes well. The optimizer definitly does something weird along the
definition/assignement of leftok/rightok..
--
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