[jira] [Commented] (QPID-7895) [linearstore] Excessive CPU utilization for some kernel clocksources
[ https://issues.apache.org/jira/browse/QPID-7895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16186145#comment-16186145 ] ASF subversion and git services commented on QPID-7895: --- Commit 81739de5a368cef2826054f7ff7962b60e4e564e in qpid-cpp's branch refs/heads/master from [~kpvdr] [ https://git-wip-us.apache.org/repos/asf?p=qpid-cpp.git;h=81739de ] QPID-7895: Additional race condition fixed > [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 (v6.4.14#64029) - To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For additional commands, e-mail: dev-h...@qpid.apache.org
[jira] [Commented] (QPID-7895) [linearstore] Excessive CPU utilization for some kernel clocksources
[ https://issues.apache.org/jira/browse/QPID-7895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16175697#comment-16175697 ] Justin Ross commented on QPID-7895: --- [~kpvdr]? > [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 (v6.4.14#64029) - To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For additional commands, e-mail: dev-h...@qpid.apache.org
[jira] [Commented] (QPID-7895) [linearstore] Excessive CPU utilization for some kernel clocksources
[ https://issues.apache.org/jira/browse/QPID-7895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16172592#comment-16172592 ] Justin Ross commented on QPID-7895: --- [~kpvdr], what's the status of this? > [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 (v6.4.14#64029) - To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For additional commands, e-mail: dev-h...@qpid.apache.org
[jira] [Commented] (QPID-7895) [linearstore] Excessive CPU utilization for some kernel clocksources
[ https://issues.apache.org/jira/browse/QPID-7895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16145418#comment-16145418 ] ASF subversion and git services commented on QPID-7895: --- Commit 0ec965f37c063cb954fb331340c091813b64501d in qpid-cpp's branch refs/heads/master from [~kpvdr] [ https://git-wip-us.apache.org/repos/asf?p=qpid-cpp.git;h=0ec965f ] QPID-7895: Further improvement of previous checkin to solve some additional possible race conditions > [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 > > 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 (v6.4.14#64029) - To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For additional commands, e-mail: dev-h...@qpid.apache.org
[jira] [Commented] (QPID-7895) [linearstore] Excessive CPU utilization for some kernel clocksources
[ https://issues.apache.org/jira/browse/QPID-7895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16136911#comment-16136911 ] ASF subversion and git services commented on QPID-7895: --- Commit 4e98f6c08ef531e15217f812f6624f18cf2d50fb in qpid-cpp's branch refs/heads/master from [~kpvdr] [ https://git-wip-us.apache.org/repos/asf?p=qpid-cpp.git;h=4e98f6c ] QPID-7895: Update to linearstore to make the flush timer more intelligent and only run when there is flushable content in the write buffers > [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 > > 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 (v6.4.14#64029) - To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For additional commands, e-mail: dev-h...@qpid.apache.org
