Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
> On 06/12/2011 11:39 PM, Robert Haas wrote:
>> Profiling reveals that the system spends enormous amounts of CPU time
>> in s_lock.
> just to reiterate that with numbers - at 160 threads with both patches
> applied the profile looks like:
> samples % image name symbol name
> 828794 75.8662 postgres s_lock
Do you know exactly which spinlocks are being contended on here?
The next few entries
> 51672 4.7300 postgres LWLockAcquire
> 51145 4.6817 postgres LWLockRelease
> 17636 1.6144 postgres GetSnapshotData
suggest that it might be the ProcArrayLock as a result of a huge amount
of snapshot-fetching, but this is very weak evidence for that theory.
regards, tom lane
