mirror of https://github.com/acidanthera/audk.git
fcd71642df
This commit is code optimization to InternalAllocateAlignedPages of SmmMemoryAllocationLib which can reduce free memory fragments. Also it can reduce one pre-allocation page. Let's take a simple example: The expected pages size is 8KB, Alignment value is 8KB. In original InternalAllocateAlignedPages(), the first step is to allocate 4 pages and then find the first 8KB-aligned address in allocated 4 pages. If the upper limit address of allocated 4 pages is already 8KB aligned, then the allocated 4 pages contains two 8KB-aligned 8KB ranges. The lower 2 pages will be selected and removed from free pages. Then the higher 2 pages will be free. Since the whole memory allocation is from high address to low address, then the higher 2 pages cann't be merged with other free pages, causing the free memory fragments. However, when only allocate 3(2+2-1) pages, we can avoid the free memory fragments in specific case. Also 3 pages must contain a 8KB-aligned 8KB range, which meets the requirement. If the upper limit address of allocated 3 pages is 8KB-aligned, then the higher 2 pages range of allocated 3 pages is 8KB-aligned and will be selected and removed from free pages. The remaining lower one page of allocated 3 pages will be free and merged with left lower free memory. This can reduce free memory fragments in smm. Signed-off-by: Dun Tan <dun.tan@intel.com> Cc: Ray Ni <ray.ni@intel.com> Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com> Cc: Liming Gao <gaoliming@byosoft.com.cn> Cc: Zhiguang Liu <zhiguang.liu@intel.com> |
||
|---|---|---|
| .. | ||
| Include | ||
| Library | ||
| Test | ||
| MdeLibs.dsc.inc | ||
| MdePkg.ci.yaml | ||
| MdePkg.dec | ||
| MdePkg.dsc | ||
| MdePkg.uni | ||
| MdePkgExtra.uni | ||