Re: [COMMITTERS] pgsql: Avoid SnapshotResetXmin() during AtEOXact_Snapshot() - Mailing list pgsql-hackers

From Robert Haas
Subject Re: [COMMITTERS] pgsql: Avoid SnapshotResetXmin() during AtEOXact_Snapshot()
Date
Msg-id CA+TgmoY0fLU1dDS36bQywaWFyT1pjKmNbZPmXFm85uQ7zYrXGw@mail.gmail.com
Whole thread Raw
In response to Re: [COMMITTERS] pgsql: Avoid SnapshotResetXmin() during AtEOXact_Snapshot()  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Fri, Mar 24, 2017 at 12:14 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Fri, Mar 24, 2017 at 10:23 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
>> Avoid SnapshotResetXmin() during AtEOXact_Snapshot()
>>
>> For normal commits and aborts we already reset PgXact->xmin
>> Avoiding touching highly contented shmem improves concurrent
>> performance.
>>
>> Simon Riggs
>
> I'm getting occasional crashes with backtraces that look like this:
>
> #4  0x0000000107e4be2b in AtEOXact_Snapshot (isCommit=<value
> temporarily unavailable, due to optimizations>, isPrepare=0 '\0') at
> snapmgr.c:1154
> #5  0x0000000107a76c06 in CleanupTransaction () at xact.c:2643
>
> I suspect that is the fault of this patch.  Please fix or revert.

Also, the entire buildfarm is turning red.

longfin, spurfowl, and magpie all show this assertion failure in the
log.  I haven't checked the others.

TRAP: FailedAssertion("!(MyPgXact->xmin == 0)", File: "snapmgr.c", Line: 1154)

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



pgsql-hackers by date:

Previous
From: Robert Haas
Date:
Subject: Re: Monitoring roles patch
Next
From: Robert Haas
Date:
Subject: Re: [PATCH] Transaction traceability - txid_status(bigint)