Re: 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets

On 14 September 2012 11:45, Daniel Farina <daniel(at)heroku(dot)com> wrote:
> Did you tell LKML? It seems like a kind of change that could be found
> using git bisect of Linux, albiet laboriously.

Hi, Daniel
I sent it to linux-kernel(at)vger(dot)kernel(dot)org on Fri, 14 Sep 2012 10:47:44
+0300.

On 14 September 2012 17:56, Marcos Ortiz <mlortiz(at)uci(dot)cu> wrote:
> Only one las t question: Did you tune the postgresql.conf for every
system? or
> Did you use the default configuration ?

Hi, Marcos

I have the issue with default and tuned configuration on all AMD systems:

Tuned config for 32Gb RAM:
#------------------------------------------------------------------------------
# Connection Settings -
#------------------------------------------------------------------------------
listen_addresses = '*'
port = 5432
max_connections = 50

#------------------------------------------------------------------------------
# OPTIMIZATIONS
#------------------------------------------------------------------------------
shared_buffers = 7680MB
effective_cache_size = 22GB
work_mem = 576MB
maintenance_work_mem = 2GB
wal_buffers = 16MB
fsync = off
synchronous_commit = off

#------------------------------------------------------------------------------
# PLANNER
#------------------------------------------------------------------------------
default_statistics_target = 100
constraint_exclusion = off

#------------------------------------------------------------------------------
# CHECKPOINTS
#------------------------------------------------------------------------------
checkpoint_timeout = 5min
checkpoint_segments = 16
checkpoint_completion_target = 0.9

#------------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#------------------------------------------------------------------------------
autovacuum = on
autovacuum_naptime = 5min
autovacuum_max_workers = 1

autovacuum_vacuum_scale_factor = 0.0001
autovacuum_analyze_scale_factor = 0.0001

autovacuum_vacuum_threshold = 100
autovacuum_analyze_threshold = 100

autovacuum_vacuum_cost_delay = 1ms

#------------------------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#------------------------------------------------------------------------------
logging_collector = on
log_directory = 'pg_log'
log_filename = 'postgresql-%a.log'
log_truncate_on_rotation = on
log_rotation_age = 1d
log_rotation_size = 0
log_line_prefix = '%t %d %u '