impala-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Dan Hecht (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-5229: huge page-backed buffers with TCMalloc
Date Thu, 20 Apr 2017 17:20:01 GMT
Dan Hecht has posted comments on this change.

Change subject: IMPALA-5229: huge page-backed buffers with TCMalloc
......................................................................


Patch Set 4:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/6687/4/be/src/runtime/bufferpool/system-allocator.cc
File be/src/runtime/bufferpool/system-allocator.cc:

PS4, Line 147: The memory region may still be backed by huge pages, but TCMalloc will decommit
             :       // those for us with its "aggressive decommit" mode.
Given our discussion, how about clarifying with something like:

"This depends on tcmalloc "aggressive decommit". Otherwise, this large page region may be
divvied up and subsequently decommitted in smaller chunks, which may not actually release
the physical memory, causing impala physical memory usage to exceed the process limit."

Probably could use some more refining, but the point is I think this should be spelled out
more.


-- 
To view, visit http://gerrit.cloudera.org:8080/6687
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: If84b46a46efed9aee6af41b5f10bf3f4b15889b8
Gerrit-PatchSet: 4
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Tim Armstrong <tarmstrong@cloudera.com>
Gerrit-Reviewer: Dan Hecht <dhecht@cloudera.com>
Gerrit-Reviewer: Tim Armstrong <tarmstrong@cloudera.com>
Gerrit-HasComments: Yes

Mime
View raw message