This series implements an updated pool allocator that performs better in a
situation where the boot time and runtime allocation alignment is different,
and where either may be substantially larger than a single page.
Without these patches applied, the pool allocations (in bytes) that are served
from the bins are as follows (on AArch64-QEMU with Intel BDS using -kernel):
LoaderData used 3232 allocated 8192
BootSvData used 198872 allocated 319488
RuntSvData used 17592 allocated 32768
However, when increasing the granularity of the allocations for runtime regions
(patches #1 and #6 applied), it becomes apparent that the current code does
not cope well in the runtime case
LoaderData used 3424 allocated 4096
BootSvData used 198872 allocated 319488
RuntSvData used 17592 allocated 524288
This series attempts to address this by changing a couple of things in the pool
allocator:
- use exponential bin sizes rather than linearly increasing with 32 bytes
- if a bin is depleted, get a block from the next bin and split it up
With all patches applied, the numbers become
LoaderData used 3136 allocated 8192
BootSvData used 195344 allocated 270336
RuntSvData used 23136 allocated 65536
Note the final 'used' number has increased: this is most likely due to a
pool allocation of > 4 KB that was formerly served by a passthrough allocation
(i.e., a pool allocation that is backed directly by a call to AllocatePages ()),
but is now served from one of the bins.
Ard Biesheuvel (6):
MdeModulePkg: use correct granularity when allocating pool pages
MdeModulePkg: improve scalability of memory pools
MdeModulePkg: use index to traverse free pool pages
MdeModulePkg: carve pool pages into the largest chunks possible
MdeModulePkg: serve allocations from higher-up bins if current bin is
empty
MdeModulePkg: use 64 KB granularity for runtime allocations on AArch64
MdeModulePkg/Core/Dxe/Mem/Imem.h | 9 +++
MdeModulePkg/Core/Dxe/Mem/Pool.c | 145 ++++++++++++++++++++++++++-------------
2 files changed, 107 insertions(+), 47 deletions(-)
--
1.8.3.2
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