MPS issue job003701

TitleMVSpanAlloc shows up in GC profiles
Assigned userDavid Lovemore
DescriptionMVSpanAlloc was showing up in profiles of CET at over 4%. [0]

See job003812 for the same issue wrt MVAlloc.
AnalysisIt looked like it was in the loop looking over spans for ones with a large enough free block. It also looked like this was happening in Seg descriptor allocation.

It is likely that there were many spans which had filled up, but with insufficient space to allocate a Seg descriptor of the right size.

Try: using MVFF for the control pool; allocating segment descriptors in MFS.
How foundmanual_test
Evidence[0] <>
Created byDavid Lovemore
Created on2014-03-17 13:50:03
Last modified byDavid Lovemore
Last modified on2014-07-04 15:30:13
History2014-03-17 DL Created


Change Effect Date User Description
186832 closed 2014-07-04 15:27:48 David Lovemore        Set CONTROL_EXTEND_BY to 32768.
The CONTROL_EXTEND_BY value for the extend by on the control pool was set really small (4096) on the assumption that the control pool was not heavily used. However, since we allocate Seg's in the control pool and recycle them frequently, this assumption is no longer true.