Re: [RFC] Should smgrtruncate() avoid sending sinval message for temp relations

From: "MauMau" <maumau307(at)gmail(dot)com>
> I must add one thing. After some client processes closed the connection
> without any hang, their server processes were stuck with a stack trace
> like this (I'll look for and show the exact stack trace tomorrow):

I found two kinds of stack traces:

#0 0x0000003199ec488f in poll () from /lib64/libc.so.6
#1 0x0000000000609f24 in WaitLatchOrSocket ()
#2 0x000000000063ad92 in SyncRepWaitForLSN ()
#3 0x00000000004ad474 in CommitTransaction ()
#4 0x00000000004aef53 in CommitTransactionCommand ()
#5 0x000000000064b547 in shmem_exit ()
#6 0x000000000064b625 in proc_exit_prepare ()
#7 0x000000000064b6a8 in proc_exit ()
#8 0x0000000000668a94 in PostgresMain ()
#9 0x0000000000617f2c in ServerLoop ()
#10 0x000000000061ae96 in PostmasterMain ()
#11 0x00000000005b2ccf in main ()

#0 0x0000003f4badf258 in poll () from /lib64/libc.so.6
#1 0x0000000000619b94 in WaitLatchOrSocket ()
#2 0x0000000000640c4c in SyncRepWaitForLSN ()
#3 0x0000000000491c18 in RecordTransactionCommit ()
#4 0x0000000000491d98 in CommitTransaction ()
#5 0x0000000000493135 in CommitTransactionCommand ()
#6 0x0000000000653fc5 in ProcessCatchupEvent ()
#7 0x00000000006540ed in HandleCatchupInterrupt ()
#8 0x00000000006533e3 in procsignal_sigusr1_handler ()
#9 <signal handler called>
#10 0x0000003f4bae96b0 in recv () from /lib64/libc.so.6
#11 0x00000000005b75f6 in secure_read ()
#12 0x00000000005c223b in pq_recvbuf ()
#13 0x00000000005c263b in pq_getbyte ()
#14 0x000000000066e081 in PostgresMain ()
#15 0x0000000000627d81 in PostmasterMain ()
#16 0x00000000005c4803 in main ()

> I'll try the fix tomorrow if possible. What kind of problems do you hink
> of for back-patching?

I could reproduce the problem with 9.2.8, but have not yet with 9.5dev.
I'll try with 9.2.9, and create the fix.

Regards
MauMau