[jira] [Updated] (IGNITE-4766) Relax worker thread wakeup logic in StipedExecutor
[
https://issues.apache.org/jira/browse/IGNITE-4766?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Vladimir Ozerov updated IGNITE-4766:
Attachment: IGNITE_4766.patch
> Relax worker thread wakeup logic in StipedExecutor
> --
>
> Key: IGNITE-4766
> URL: https://issues.apache.org/jira/browse/IGNITE-4766
> Project: Ignite
> Issue Type: Task
> Components: general
>Affects Versions: 1.9
>Reporter: Vladimir Ozerov
>Assignee: Vladimir Ozerov
> Fix For: 2.1
>
> Attachments: IGNITE_4766.patch
>
>
> *Problem*
> Worker threads in {{StripedExecutor}} have {{parked}} state flag. When set to
> {{true}} NIO threads will call {{LockSupport.unpark}} after submitting new
> task to a queue.
> The problem is that this flag is only changed by worker thread. Thus, if NIO
> worker submitted a new task and called {{unpark}}, worker will clean up
> {{parked}} state only after real wake up what may take microseconds. All
> subsequent submits from NIO thread occurred during this time will also invoke
> {{unpark}} thus generating high contention on the underlying OS primitives.
> Namely, condition variables which ultimately delegates to {{futex}} on Linux.
> *Solution*
> NIO threads must be able to clear {{parked}} state as well. Some CAS magic
> will be required there. This way we will minimize number of {{unapark}} calls.
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[jira] [Updated] (IGNITE-4766) Relax worker thread wakeup logic in StipedExecutor
[
https://issues.apache.org/jira/browse/IGNITE-4766?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Vladimir Ozerov updated IGNITE-4766:
Fix Version/s: (was: 2.0)
2.1
> Relax worker thread wakeup logic in StipedExecutor
> --
>
> Key: IGNITE-4766
> URL: https://issues.apache.org/jira/browse/IGNITE-4766
> Project: Ignite
> Issue Type: Task
> Components: general
>Affects Versions: 1.9
>Reporter: Vladimir Ozerov
>Assignee: Vladimir Ozerov
> Fix For: 2.1
>
>
> *Problem*
> Worker threads in {{StripedExecutor}} have {{parked}} state flag. When set to
> {{true}} NIO threads will call {{LockSupport.unpark}} after submitting new
> task to a queue.
> The problem is that this flag is only changed by worker thread. Thus, if NIO
> worker submitted a new task and called {{unpark}}, worker will clean up
> {{parked}} state only after real wake up what may take microseconds. All
> subsequent submits from NIO thread occurred during this time will also invoke
> {{unpark}} thus generating high contention on the underlying OS primitives.
> Namely, condition variables which ultimately delegates to {{futex}} on Linux.
> *Solution*
> NIO threads must be able to clear {{parked}} state as well. Some CAS magic
> will be required there. This way we will minimize number of {{unapark}} calls.
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[jira] [Updated] (IGNITE-4766) Relax worker thread wakeup logic in StipedExecutor
[
https://issues.apache.org/jira/browse/IGNITE-4766?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Vladimir Ozerov updated IGNITE-4766:
Affects Version/s: (was: 1.0)
1.9
> Relax worker thread wakeup logic in StipedExecutor
> --
>
> Key: IGNITE-4766
> URL: https://issues.apache.org/jira/browse/IGNITE-4766
> Project: Ignite
> Issue Type: Task
> Components: general
>Affects Versions: 1.9
>Reporter: Vladimir Ozerov
>Assignee: Vladimir Ozerov
> Fix For: 2.0
>
>
> *Problem*
> Worker threads in {{StripedExecutor}} have {{parked}} state flag. When set to
> {{true}} NIO threads will call {{LockSupport.unpark}} after submitting new
> task to a queue.
> The problem is that this flag is only changed by worker thread. Thus, if NIO
> worker submitted a new task and called {{unpark}}, worker will clean up
> {{parked}} state only after real wake up what may take microseconds. All
> subsequent submits from NIO thread occurred during this time will also invoke
> {{unpark}} thus generating high contention on the underlying OS primitives.
> Namely, condition variables which ultimately delegates to {{futex}} on Linux.
> *Solution*
> NIO threads must be able to clear {{parked}} state as well. Some CAS magic
> will be required there. This way we will minimize number of {{unapark}} calls.
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