| From: | Konstantin Knizhnik <k(dot)knizhnik(at)postgrespro(dot)ru> |
|---|---|
| To: | PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Cc: | Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, Bernd Helmle <mailings(at)oopsware(dot)de> |
| Subject: | Re: Deadlock in XLogInsert at AIX |
| Date: | 2017-02-01 11:07:56 |
| Message-ID: | 7609057e-b021-56d8-afb6-27acc1dfdeea@postgrespro.ru |
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| Lists: | 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
| Attachment | Content-Type | Size |
|---|---|---|
| xlc.patch | text/x-patch | 3.1 KB |
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