Re: [HACKERS] Deadlock in XLogInsert at AIX - Mailing list pgsql-hackers

From Konstantin Knizhnik
Subject Re: [HACKERS] Deadlock in XLogInsert at AIX
Date
Msg-id 7609057e-b021-56d8-afb6-27acc1dfdeea@postgrespro.ru
Whole thread Raw
In response to Re: [HACKERS] Deadlock in XLogInsert at AIX  (Heikki Linnakangas <hlinnaka@iki.fi>)
Responses Re: [HACKERS] Deadlock in XLogInsert at AIX  (Heikki Linnakangas <hlinnaka@iki.fi>)
Re: [HACKERS] Deadlock in XLogInsert at AIX  (Heikki Linnakangas <hlinnaka@iki.fi>)
Re: [HACKERS] Deadlock in XLogInsert at AIX  ("REIX, Tony" <tony.reix@atos.net>)
List pgsql-hackers
Attached please find my patch for XLC/AIX.
The most critical fix is adding __sync to pg_atomic_fetch_add_u32_impl.
The comment in this file says that:

       * __fetch_and_add() emits a leading "sync" and trailing "isync", 
thereby
       * providing sequential consistency.  This is undocumented.

But it is not true any more (I checked generated assembler code in 
debugger).
This is why I have added __sync() to this function. Now pgbench working 
normally.

Also there is mysterious disappearance of assembler section function 
with sync instruction from pg_atomic_compare_exchange_u32_impl.
I have fixed it by using __sync() built-in function instead.


Thanks to everybody who helped me to locate and fix this problem.

-- 

Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company


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