linux-kernel - Re: [PATCH v9 10/15] x86/sgx: Add EPC reclamation in cgroup try

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

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Fri, 23 Feb 2024 10:18:18 +0000
From: "Huang, Kai" <kai.huang@...el.com>
To: "Mehta, Sohil" <sohil.mehta@...el.com>, "mingo@...hat.com"
	<mingo@...hat.com>, "jarkko@...nel.org" <jarkko@...nel.org>, "x86@...nel.org"
	<x86@...nel.org>, "dave.hansen@...ux.intel.com"
	<dave.hansen@...ux.intel.com>, "cgroups@...r.kernel.org"
	<cgroups@...r.kernel.org>, "hpa@...or.com" <hpa@...or.com>,
	"tim.c.chen@...ux.intel.com" <tim.c.chen@...ux.intel.com>,
	"linux-sgx@...r.kernel.org" <linux-sgx@...r.kernel.org>, "mkoutny@...e.com"
	<mkoutny@...e.com>, "haitao.huang@...ux.intel.com"
	<haitao.huang@...ux.intel.com>, "tglx@...utronix.de" <tglx@...utronix.de>,
	"tj@...nel.org" <tj@...nel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "bp@...en8.de" <bp@...en8.de>
CC: "mikko.ylinen@...ux.intel.com" <mikko.ylinen@...ux.intel.com>,
	"seanjc@...gle.com" <seanjc@...gle.com>, "anakrish@...rosoft.com"
	<anakrish@...rosoft.com>, "Zhang, Bo" <zhanb@...rosoft.com>,
	"kristen@...ux.intel.com" <kristen@...ux.intel.com>, "yangjie@...rosoft.com"
	<yangjie@...rosoft.com>, "Li, Zhiquan1" <zhiquan1.li@...el.com>,
	"chrisyan@...rosoft.com" <chrisyan@...rosoft.com>
Subject: Re: [PATCH v9 10/15] x86/sgx: Add EPC reclamation in cgroup
 try_charge()

> > 
> Right. When code reaches to here, we already passed reclaim per cgroup.  

Yes if try_charge() failed we must do pre-cgroup reclaim.

> The cgroup may not at or reach limit but system has run out of physical  
> EPC.
> 

But after try_charge() we can still choose to reclaim from the current group,
but not necessarily have to be global, right?  I am not sure whether I am
missing something, but could you elaborate why we should choose to reclaim from
the global?