| From: | KONDO Mitsumasa <kondo(dot)mitsumasa(at)lab(dot)ntt(dot)co(dot)jp> |
|---|---|
| To: | Aidan Van Dyk <aidan(at)highrise(dot)ca>, Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: drop duplicate buffers in OS |
| Date: | 2014-01-17 07:33:11 |
| Message-ID: | 52D8DCB7.90503@lab.ntt.co.jp |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
(2014/01/16 21:38), Aidan Van Dyk wrote:
> Can we just get the backend that dirties the page to the posix_fadvice DONTNEED?
No, it can remove clean page in OS file caches. Because if page is dirtied, it
cause physical-disk-writing. However, it is experimental patch so it might be
changed by future benchmark testing.
> Or have another helper that sweeps the shared buffers and does this post-first-dirty?
We can add DropDuplicateOSCache() function to checkpointer process or other
process. And we can chenged posix_fadvice() DONTNEED to sync_file_range(). It can
cause physical-disk-writing in target buffer, not to free OS file caches.
I'm considering that sync_file_range() SYNC_FILE_RANGE_WAIT_BEFORE |
SYNC_FILE_RANGE_WRITE in executing checkpoint. It can avoid fsync freeze
situaition in part of of finnal checkpoint.
Regards,
--
Mitsumasa KONDO
NTT Open Source Software Center
| From | Date | Subject | |
|---|---|---|---|
| Next Message | KONDO Mitsumasa | 2014-01-17 07:35:01 | Re: drop duplicate buffers in OS |
| Previous Message | Michael Paquier | 2014-01-17 07:18:04 | Re: Backup throttling |