Messages in this thread | | | Date | Tue, 11 Jan 2022 09:39:30 -0800 | Subject | Re: [PATCH v2 1/2] x86/sgx: Add accounting for tracking overcommit | From | Dave Hansen <> |
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On 1/11/22 08:33, Haitao Huang wrote: > On Tue, 11 Jan 2022 09:43:35 -0600, Dave Hansen <dave.hansen@intel.com> > wrote: >> On 1/11/22 06:20, Haitao Huang wrote: >>> If the system has a ton of RAM but limited EPC, I think it makes >>> sense to allow more EPC swapping, can we do min(0.5*RAM, 2*EPC)? >>> I suppose if the system is used for heavy enclave load, user would be >>> willing to at least use half of RAM. >> >> If I have 100GB of RAM and 100MB of EPC, can I really *meaningfully* >> run 50GB of enclaves? In that case, if everything was swapped out >> evenly, I would only have a 499/500 chance that a given page reference >> would fault. > > The formula will cap swapping at 2*EPC so only 200MB swapped out. So > the miss is at most 1/3. > The original hard coded cap 1.5*EPC may still consume too much RAM if > RAM<1.5*EPC.
Oh, sorry, I read that backwards.
Basing it on the amount of RAM is a bit nasty. You might either really overly restrict the amount of allowed EPC, or you have to handle hotplug.
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