linux-kernel - RE: [PATCH v2 06/33] Documentation, x86: Documentation for Intel resource allocation user interface

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Fri, 9 Sep 2016 21:59:51 +0000
From:   "Luck, Tony" <tony.luck@...el.com>
To:     Shaohua Li <shli@...com>
CC:     "Yu, Fenghua" <fenghua.yu@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Anvin, H Peter" <h.peter.anvin@...el.com>,
        Ingo Molnar <mingo@...e.hu>,
        Peter Zijlstra <peterz@...radead.org>,
        Tejun Heo <tj@...nel.org>, Borislav Petkov <bp@...e.de>,
        Stephane Eranian <eranian@...gle.com>,
        Marcelo Tosatti <mtosatti@...hat.com>,
        "David Carrillo-Cisneros" <davidcc@...gle.com>,
        "Shankar, Ravi V" <ravi.v.shankar@...el.com>,
        Vikas Shivappa <vikas.shivappa@...ux.intel.com>,
        "Prakhya, Sai Praneeth" <sai.praneeth.prakhya@...el.com>,
        linux-kernel <linux-kernel@...r.kernel.org>, x86 <x86@...nel.org>
Subject: RE: [PATCH v2 06/33] Documentation, x86: Documentation for Intel
 resource allocation user interface

> Hmm, I don't know how applications are going to use the interface. Nobody knows
> it right now. But we do have some candicate workloads which want to configure
> the cache partition at runtime, so it's not just a boot time stuff. I'm
> wondering why we have such limitation. The framework is there, it's quite easy
> to implement process move in kernel but fairly hard to get it right in
> userspace.

You are correct - if there is a need for this, it would be better done in the kernel.

I'm just not sure how to explain both a "procs" and "tasks" interface file in a way
that won't confuse people.

We have:

# echo {task-id} > tasks
  .... adds a single task to this resource group
# cat tasks
  ... shows all the tasks in this resource group

and you want:

# echo {process-id} > procs
   ... adds all threads in {process-id} to this resource group
# cat procs
  ... shows all processes (like "cat tasks" above, but only shows main thread in a multi-threads process)