Re: Bottlenecks with large number of relation segment files - Mailing list pgsql-general

From KONDO Mitsumasa
Subject Re: Bottlenecks with large number of relation segment files
Date
Msg-id 5200CB42.1090402@lab.ntt.co.jp
Whole thread Raw
In response to Re: Bottlenecks with large number of relation segment files  (Andres Freund <andres@2ndquadrant.com>)
List pgsql-general
(2013/08/05 19:28), Andres Freund wrote:
> On 2013-08-05 18:40:10 +0900, KONDO Mitsumasa wrote:
>> (2013/08/05 17:14), Amit Langote wrote:
>>> So, within the limits of max_files_per_process, the routines of file.c
>>> should not become a bottleneck?
>> It may not become bottleneck.
>> 1 FD consumes 160 byte in 64bit system. See linux manual at "epoll".
>
> That limit is about max_user_watches, not the general cost of an
> fd. Afair they take up a a good more than that.
OH! It's my mistake... I retry to read about FD in linux manual at "proc".
It seems that a process having FD can see in /proc/[pid]/fd/.
And it seems symbolic link and consume 64byte memory per FD.

Regards,
--
Mitsumasa KONDO
NTT Open Source Software Center



























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