Re: v15b1: FailedAssertion("segment_map->header->magic == (DSA_SEGMENT_HEADER_MAGIC ^ area->control->handle ^ index)", File: "dsa.c", ..) - Mailing list pgsql-hackers

On Wed, Apr 12, 2023 at 11:18:36AM +1200, Thomas Munro wrote:
> Can you print *area->control?

(gdb) p *area->control
$1 = {segment_header = {magic = 216163848, usable_pages = 62, size = 1048576, prev = 1, next = 18446744073709551615,
bin= 4, freed = false}, handle = 0, segment_handles = {0, 3696856876, 433426374, 1403332952, 2754923922, 
 
    0 <repeats 1019 times>}, segment_bins = {18446744073709551615, 18446744073709551615, 18446744073709551615,
18446744073709551615,3, 4, 18446744073709551615, 18446744073709551615, 18446744073709551615, 
 
    18446744073709551615, 18446744073709551615, 18446744073709551615, 18446744073709551615, 18446744073709551615,
18446744073709551615,18446744073709551615}, pools = {{lock = {tranche = 72, state = {value = 536870912}, 
 
        waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 2199025295360, 8192, 0}}, {lock = {tranche = 72,
state= {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 
 
        2199025296088, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail =
2147483647}},spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {
 
          head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value =
536870912},waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, 
 
        state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 
 
        0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail =
2147483647}},spans = {0, 2199025296648, 2199025298608, 0}}, {lock = {tranche = 72, state = {value = 536870912}, 
 
        waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value
=536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {
 
        tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0,
0}},{lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, 
 
          tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters =
{head= 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {
 
          value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 
 
        0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}},
spans= {0, 2199025298496, 2199025298664, 2199025297936}}, {lock = {tranche = 72, state = {
 
          value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 
 
        0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}},
spans= {0, 8416, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, 
 
          tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters =
{head= 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {
 
          value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 
 
        0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}},
spans= {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, 
 
          tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters =
{head= 2147483647, tail = 2147483647}}, spans = {0, 8304, 0, 0}}, {lock = {tranche = 72, state = {
 
          value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 
 
        0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}},
spans= {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, 
 
          tail = 2147483647}}, spans = {0, 8528, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters =
{head= 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {
 
          value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 8248, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 
 
        0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}},
spans= {0, 8584, 0, 0}}, {lock = {tranche = 72, state = {value = 536870912}, waiters = {
 
          head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, state = {value =
536870912},waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock = {tranche = 72, 
 
        state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 0, 0, 0}}, {lock =
{tranche= 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}, spans = {0, 
 
        8640, 0, 0}}}, total_segment_size = 9699328, max_total_segment_size = 18446744073709551615, high_segment_index
=4, refcnt = 8455469, pinned = true, freed_segment_counter = 0, lwlock_tranche_id = 72, lock = {
 
    tranche = 72, state = {value = 536870912}, waiters = {head = 2147483647, tail = 2147483647}}}

> And then can you see that the DSM handle is in index 1 in "segment_handles"
> in there?

(gdb) p area->control->segment_handles 
$2 = {0, 3696856876, 433426374, 1403332952, 2754923922, 0 <repeats 1019 times>}

> Then can you see if your system has a file with that number in its name under
> /dev/shm/,

$ ls /dev/shm/ |grep 3696856876 || echo not found
not found

(In case it matters: the vm has been up for 1558 days).

If it's helpful, I could provide the corefile, unstripped binaries, and
libc.so, which would be enough to use gdb on your side with "set
solib-search-path".

-- 
Justin