d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Since r251709 a slab no longer use 8-bit indicies to manage items,

Browse Source 
thus remove a stale comment.

Reviewed by:	jeff
This commit is contained in:
Gleb Smirnoff 2013-07-24 06:13:00 +00:00
parent ef1f916971
commit dab12c75bb
1 changed files with 0 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
sys/vm/uma_int.h
View File

@ -49,14 +49,6 @@
* 10% memory waste we potentially allocate a separate uma_slab_t if this will * 10% memory waste we potentially allocate a separate uma_slab_t if this will
* improve the number of items per slab that will fit. * improve the number of items per slab that will fit.
* *
* Other potential space optimizations are storing the 8bit of linkage in space
* wasted between items due to alignment problems. This may yield a much better
* memory footprint for certain sizes of objects. Another alternative is to
* increase the UMA_SLAB_SIZE, or allow for dynamic slab sizes. I prefer
* dynamic slab sizes because we could stick with 8 bit indices and only use
* large slab sizes for zones with a lot of waste per slab. This may create
* inefficiencies in the vm subsystem due to fragmentation in the address space.
*
* The only really gross cases, with regards to memory waste, are for those * The only really gross cases, with regards to memory waste, are for those
* items that are just over half the page size. You can get nearly 50% waste, * items that are just over half the page size. You can get nearly 50% waste,
* so you fall back to the memory footprint of the power of two allocator. I * so you fall back to the memory footprint of the power of two allocator. I