Messages in this thread | | | Date | Mon, 9 Jan 2017 14:17:55 -0800 | From | Fenghua Yu <> | Subject | Re: [PATCH] x86/intel_rdt: reinitialize cbm for new group allocation |
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On Mon, Jan 09, 2017 at 11:03:59PM +0100, Thomas Gleixner wrote: > On Mon, 9 Jan 2017, Fenghua Yu wrote: > > On Fri, Jan 06, 2017 at 04:05:19PM -0800, Shaohua Li wrote: > > But since you come here now, I would think reseting the CBM in > > closid_free() is better. > > No. closid_free() is the wrong place. closid_alloc/free() merily deal with > the bitmap and nothing else. > > If you really want to do that, then this needs a seperate function called > from rmdir. > > > The reason is user can see "right" max_cbm even through rdmsr after > > rmdir, ie no gap for cbm values between rmdir and the next mkdir. > > And the value pf this is?
Not very useful value, but user may get a bit confused by a non max_cbm if a closid is not used after rdmsr. A couple of users actually asked this. Reseting to initial max_cbm may reduce questions from users.
> > The closid is not usable after the rmdir, so it's really completely > uninteresting when the user can read the old value from that configuration > MSR.
Agree with you. The cbm value is uninteresting after rmdir.
> > When the closid is reused then it hardly matters either what's in those cbm > values (the old or max_cbm). > > Thanks, > > tglx
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