[
https://issues.apache.org/jira/browse/ARROW-1795?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16256620#comment-16256620
]
ASF GitHub Bot commented on ARROW-1795:
---------------------------------------
luchy0120 commented on issue #1327: ARROW-1795: [Plasma] Create flag to make
Plasma store use a single memory-mapped file.
URL: https://github.com/apache/arrow/pull/1327#issuecomment-345174100
then, we still have potential to get outofmemory after long run. But then
our require_space() will try to
evict small objects and "doug lea" will help us to make up small free
fragments into large whole free space. But how do we promise that every time
we call dlmemalign ,it will reuse the big mmap memory and every time we call
dlfree it will not unmap ?
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
> [Plasma C++] change evict policy
> --------------------------------
>
> Key: ARROW-1795
> URL: https://issues.apache.org/jira/browse/ARROW-1795
> Project: Apache Arrow
> Issue Type: Improvement
> Components: Plasma (C++)
> Reporter: Lu Qi
> Assignee: Robert Nishihara
> Priority: Minor
> Labels: pull-request-available
> Fix For: 0.8.0
>
>
> case 1.say, we have total free memory 8 G , we have input 5G data, then comes
> another 6G data,
> if we choose to evict space 6G , it will throw exception saying that
> no object can be free. This is because we didn't count the 3G remaining free
> space .If we count this remaining 3G , we need to ask only 3G,thus
> we can evict the 5G data and we are still alive .
> case 2. another situation is : if we have free memory 10G , we input 1.5G
> data ,then comes another
> 9G data , if we use 10*20% = 2G data to evict ,then we will crash . In this
> situation we need to
> use 9+1.5-10 = 0.5G data to evict
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
