From: | Amit Kapila <amit(dot)kapila(at)huawei(dot)com> |
---|---|
To: | "'PostgreSQL-development'" <pgsql-hackers(at)postgreSQL(dot)org> |
Subject: | Move unused buffers to freelist |
Date: | 2013-05-14 13:42:27 |
Message-ID: | 002f01ce50a8$e057c7a0$a10756e0$@kapila@huawei.com |
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Lists: | pgsql-hackers |
As discussed and concluded in mail thread
(http://www.postgresql.org/message-id/006f01ce34f0$d6fa8220$84ef8660$@kapila
@huawei.com), for moving unused buffer's to freelist end,
I having implemented the idea and taken some performance data.
In the attached patch, bgwriter/checkpointer moves unused (usage_count =0 &&
refcount = 0) buffer's to end of freelist. I have implemented a new API
StrategyMoveBufferToFreeListEnd() to
move buffer's to end of freelist.
Performance Data :
Configuration Details
O/S - Suse-11
RAM - 24GB
Number of Cores - 8
Server Conf - checkpoint_segments = 256; checkpoint_timeout = 25 min,
synchronous_commit = 0FF, shared_buffers = 5GB
Pgbench - Select-only
Scalefactor - 1200
Time - Each run is of 20 mins
Below data is for average 3 runs of 20 minutes
8C-8T 16C-16T 32C-32T
64C-64T
HEAD 11997 8455 4989
2757
After Patch 19807 13296 8388
2821
Detailed each run data is attached with mail.
This is just the initial data, I will collect more data based on different
configuration of shared buffers and other configurations.
Feedback/Suggesions?
With Regards,
Amit Kapila.
Attachment | Content-Type | Size |
---|---|---|
move_unused_buffers_to_freelist.htm | text/html | 23.3 KB |
move_unsed_buffers_to_freelist.patch | application/octet-stream | 4.4 KB |
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