qpid-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Justin Ross (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (QPID-7895) [linearstore] Excessive CPU utilization for some kernel clocksources
Date Fri, 22 Sep 2017 00:16:00 GMT

    [ https://issues.apache.org/jira/browse/QPID-7895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16175697#comment-16175697

Justin Ross commented on QPID-7895:


> [linearstore] Excessive CPU utilization for some kernel clocksources
> --------------------------------------------------------------------
>                 Key: QPID-7895
>                 URL: https://issues.apache.org/jira/browse/QPID-7895
>             Project: Qpid
>          Issue Type: Bug
>          Components: C++ Broker
>            Reporter: Kim van der Riet
>            Assignee: Kim van der Riet
>             Fix For: qpid-cpp-1.37.0
> For some kernel clocksources (eg acpi_pm), it has been observed that there is an excessively
high CPU utilization which correlates with the linearstore's flush timeout being set to a
very low value (100us).  This is a problem for some customers which require almost instant
flush to obtain pseudo-synchronous store behavior (hence the 100us flush timer) and run many
brokers (up to hundreds) on a single machine.  In these cases, the CPU is 100% utilized.
> A check of the source shows that the flush timer is firing continuously, irrespective
of whether any disk I/O has taken place.
> It is proposed that a change to linearstore be made which will only run the timer when
needed (ie while there is content in the write buffers that needs flushing).

This message was sent by Atlassian JIRA

To unsubscribe, e-mail: dev-unsubscribe@qpid.apache.org
For additional commands, e-mail: dev-help@qpid.apache.org

View raw message