[release/7.0] Remove page map from PAL virtual memory allocator #80173
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mangod9
approved these changes
Jan 4, 2023
jeffschwMSFT
approved these changes
Jan 4, 2023
The page bitmap removal in PAL that was made recently has introduced a subtle bug when the `VIRTUALCommitMemory` was returning incorrect address when a region of memory was reserved and later a smaller subset of that region that didn't start at the beginning of the reserved region was committed. It was returning the address of the originally reserved region. While we have not hit any issues in the main branch, a backport of this change has caused CI failures on macOS due to the issue.
rbhanda
added
Servicing-approved
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Approved by Tactics (7.0.3). |
ghost
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Backport of #80105 to release/7.0
/cc @janvorli
Customer Impact
This fix removes the 64mb PAL overhead when reserving 256gb of memory since its done by default with Regions.
Testing
Manual validation that the working set is lower with this change (about 64mb less for simple hello world applications)
Risk
Low, its mostly removing code which is not used within the runtime.
IMPORTANT: Is this backport for a servicing release? If so and this change touches code that ships in a NuGet package, please make certain that you have added any necessary package authoring and gotten it explicitly reviewed.