lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 11 Jan 2022 09:39:30 -0800 From: Dave Hansen <dave.hansen@...el.com> To: Haitao Huang <haitao.huang@...ux.intel.com>, linux-sgx@...r.kernel.org, Jarkko Sakkinen <jarkko@...nel.org>, Dave Hansen <dave.hansen@...ux.intel.com>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>, Kristen Carlson Accardi <kristen@...ux.intel.com> Cc: linux-kernel@...r.kernel.org Subject: Re: [PATCH v2 1/2] x86/sgx: Add accounting for tracking overcommit On 1/11/22 08:33, Haitao Huang wrote: > On Tue, 11 Jan 2022 09:43:35 -0600, Dave Hansen <dave.hansen@...el.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.
Powered by blists - more mailing lists