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https://issues.apache.org/jira/browse/IMPALA-7239?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16535328#comment-16535328
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Tim Armstrong commented on IMPALA-7239:
---------------------------------------
/maps still has the [stack:<pid>] info that's expensive to compute:
{noformat}
7fc89ac74000-7fc89b474000 rw-p 00000000 00:00 0
[stack:1864690]
{noformat}
Same with /numa_maps:
{noformat}
7fc89ac74000 prefer:0 stack:1864690 anon=3 dirty=3 N0=3 kernelpagesize_kB=4
{noformat}
This is on 3.10.0-327.36.3.el7.x86_64
> Mitigate ParseSmaps() overhead
> ------------------------------
>
> Key: IMPALA-7239
> URL: https://issues.apache.org/jira/browse/IMPALA-7239
> Project: IMPALA
> Issue Type: Bug
> Components: Backend
> Affects Versions: Impala 2.10.0, Impala 2.11.0, Impala 3.0, Impala 2.12.0
> Reporter: Tim Armstrong
> Assignee: Tim Armstrong
> Priority: Critical
> Labels: perf, resource-management
> Attachments: mmap.c
>
>
> I've heard anecdotes of high system time spent in functions related this the
> smap parsing. It appears that this can be expensive on systems once the
> impalad virtual memory gets fragmented and there are 10s of thousands of maps.
> We can try to mitigate by reducing frequency of the parsing or disabling it
> entirely. I'm not sure if there are cheaper ways to get all of the same
> metrics.
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