[
https://issues.apache.org/jira/browse/DISPATCH-1352?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16854666#comment-16854666
]
Ken Giusti commented on DISPATCH-1352:
--------------------------------------
Further discussion with [~ganeshmurthy] on this - possible impl detail:
Instead of allocating a qd_message_pvt_t structure we allocate a single block
of memory large enuff to hold the qd_message_pv_t structure and N qd_buffer_t
structures and lay them down "cheek to jowl" in the buffer, linking the
qd_buffer_ts as normal, but incrementing the refcount to prevent freeing them
individually.
That would avoid the extra calls to qd_buffer_t allocate, make better use of
the cache (fingers crossed) all without having to touch the iterator code
(which is everywhere and expects qd_buffer_t based data).
> qd_buffer_list_clone cost is dominated by cache misses
> ------------------------------------------------------
>
> Key: DISPATCH-1352
> URL: https://issues.apache.org/jira/browse/DISPATCH-1352
> Project: Qpid Dispatch
> Issue Type: Improvement
> Components: Routing Engine
> Affects Versions: 1.7.0
> Reporter: Francesco Nigro
> Priority: Major
> Attachments: screenshot-1.png, screenshot-2.png
>
>
> qd_buffer_list_clone on qd_message_copy for
> qd_message_pvt_t.ma_to_override/ma_trace/ma_ingress is dominated by cache
> misses costs:
> * to "allocate" new qd_buffer_t
> * to reference any qd_buffer_t from the source qd_buffer_list_t
> Such cost is the main reason why the core thread is having a very low IPC (<
> 1 istr/cycle) and given the single threaded nature of the router while
> dealing with it, by solving it will bring a huge performance improvement to
> make the router able to scale better.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
