Memory allocation peculiarity...

I have a Windows 10 system that has 128GB of RAM. I know this is not a good practice, but I’m allocating 64GB of that RAM as common buffers in 1024 64MB chunks. However, when I attempt to acquire the same amount of memory in a larger chunk size (e.g. 512 128MB chunks) the system does not boot. Can someone shed some light on why this happens?

Can you define “does not boot”?

If it’s a hang, what do you see when you break into the debugger and look at what’s currently on the processors and which !locks are held?

-p

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Subject: [ntdev] Memory allocation peculiarity…

I have a Windows 10 system that has 128GB of RAM. I know this is not a good practice, but I’m allocating 64GB of that RAM as common buffers in 1024 64MB chunks. However, when I attempt to acquire the same amount of memory in a larger chunk size (e.g. 512 128MB chunks) the system does not boot. Can someone shed some light on why this happens?


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I believe you need to shed some light on why would you need to do what you are trying to do for even experimental purposes ?
And then allocating 128 MB chunks of common buffer implying you need that much memory contiguous for each of those chunks can be causing other contiguous allocations for other devices on the machine fail whereas the 64MB allocations may be leaving contiguous chunks for other devices. And then there could be devices whose driver are looking for physically contiguous memory in specific (say 32 bit addressable range) which might be getting exhausted by your experiment. You can analyze the hang further to determine whats causing the hang but unless there is a good reason to do what you are doing, that may not be worth it.

Can you define “does not boot”?

I see the Dell boot screen, then the system restarts.

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If it’s a hang, what do you see when you break into the debugger and look at what’s
currently on the processors and which !locks are held?

I will break in the debugger and check. Thanks.