lkml.org 
[lkml]   [2017]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 08/21] x86/intel_rdt/cqm: Add RMID(Resource monitoring ID) management
> In case that a RMID was never used on a particular package, the state check
> forces an IPI on all packages unconditionally. That's suboptimal at least.
>
> We know on which package a given RMID was used, so we could restrict the
> checks to exactly these packages, but I'm not sure it's worth the
> trouble. We might at least document that and explain why this is
> implemented in that way.

We only allocate RMIDs when a user makes a directory. I don't think
we should consider options that slow down context switch in order to
keep track of which packages were used just to make mkdir(2) a bit faster
in the case where we need to check the limbo list.

We could make the check of the limbo list less costly by using a bitmask
to keep track of which packages have already found that the llc_occupancy
is below the threshold. But I'd question whether the extra complexity in the
code was really worth it.

-Tony [on vacation - responses will be slow]

\
 
 \ /
  Last update: 2017-07-05 20:00    [W:0.214 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site