Feature Request: How much time was spent waiting for I/O requests (related to paging file) during processing of large data sets

Feature Request: How much time was spent waiting for I/O requests (related to paging file) during processing of large data sets

This is a Feature Request ( actually suggested by Jim ):

How much time was spent waiting for I/O requests ( related to paging file ) during processing.

Note: We have a discussion on Intel C++ Compiler Forum ( http://software.intel.com/en-us/forums/topic/401303 ) related to processing of very large data sets exceeding size of Physical Memory ( in 3x - 5x ). Or, may be such functionality is already available in Intel PCM?

 

6 posts / 0 new
Last post
For more complete information about compiler optimizations, see our Optimization Notice.

This is a long story in your issue discussed in Compiler Forum...thank you.

1. If you use lightweight-hotspots (now called advanced-hotspots in U10/U11) and enable "context switches" before collecting data. Change "Hardware Event Sample Counts" as viewpoint in bottom-up report, there is a column named "Wait Time". Wait-time could be caused by many reasons, such as io-wait (File operations, Page walks, Wait message, etc), or thread suspending, etc.

2. If you want to identify issue caused by page walks - suggest to use hardware PMU events, for example:

DTLB_LOAD_MISSES, DTLB_STORE_MISSES ; they are supported in SandyBridge processors

You can use DTLB_STORE_MISSES.WALK_DURATION to measure Cycles of busy during page walks

>>1. If you use lightweight-hotspots (now called advanced-hotspots in U10/U11) and enable "context switches" before collecting data.
>>Change "Hardware Event Sample Counts" as viewpoint in bottom-up report, there is a column named "Wait Time". Wait-time
>>could be caused by many reasons, such as io-wait (File operations, Page walks, Wait message, etc), or thread suspending, etc...

I'll take a look. Thanks, Peter.

Hi Peter

is the Wait Time setting global(system-wide) or it can be charged against some thread(s)

Thanks in advance

Hi iliyapolak,

All Wait Time data will be charged on functions, these data can be categorized into threads for view.

Regards, Peter

Thank you Peter

Leave a Comment

Please sign in to add a comment. Not a member? Join today