From: Thomas Gleixner <tglx@linutronix.de>
To: Reinette Chatre <reinette.chatre@intel.com>
Cc: fenghua.yu@intel.com, tony.luck@intel.com,
jithu.joseph@intel.com, gavin.hindman@intel.com,
dave.hansen@intel.com, mingo@redhat.com, hpa@zytor.com,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] x86/intel_rdt: CBM overlap should also check for overlap with CDP peer
Date: Wed, 3 Oct 2018 09:02:27 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1810030848580.1435@nanos.tec.linutronix.de> (raw)
In-Reply-To: <262e12b66c238517c4766190dd493d937825f563.1537987801.git.reinette.chatre@intel.com>
On Wed, 26 Sep 2018, Reinette Chatre wrote:
> /**
> - * rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
> + * _rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
> * @r: Resource to which domain instance @d belongs.
> * @d: The domain instance for which @closid is being tested.
> * @cbm: Capacity bitmask being tested.
> @@ -1049,8 +1048,8 @@ static int __attribute__((unused)) rdt_cdp_peer_get(struct rdt_resource *r,
> *
> * Return: false if CBM does not overlap, true if it does.
> */
> -bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
> - u32 _cbm, int closid, bool exclusive)
> +static bool _rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
> + u32 _cbm, int closid, bool exclusive)
Existing issue. The documentation uses @cbm, but the argument is _cbm.
Also please make this __rdtgroup_cbm_overlaps(). Double underscores are
standing more out.
> {
> unsigned long *cbm = (unsigned long *)&_cbm;
> unsigned long *ctrl_b;
> @@ -1087,6 +1086,44 @@ bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
> return false;
> }
>
> +/**
> + * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
> + * @r: Resource to which domain instance @d belongs.
> + * @d: The domain instance for which @closid is being tested.
> + * @cbm: Capacity bitmask being tested.
> + * @closid: Intended closid for @cbm.
> + * @exclusive: Only check if overlaps with exclusive resource groups
> + *
> + * Resources that can be allocated using a CBM can use the CBM to control
> + * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
> + * for overlap. Overlap test is not limited to the specific resource for
> + * which the CBM is intended though - when dealing with CDP resources that
> + * share the underlying hardware the overlap check should be performed on
> + * the CDP resource sharing the hardware also.
> + *
> + * Refer to description of _rdtgroup_cbm_overlaps() for the details of the
> + * overlap test.
> + *
> + * Return: true if CBM overlap detected, false if there is no overlap
> + */
> +bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
> + u32 _cbm, int closid, bool exclusive)
Ditto. And here is no reason for using _cbm.
> +{
> + struct rdt_resource *r_cdp;
> + struct rdt_domain *d_cdp;
> + bool ret;
> +
> + ret = _rdtgroup_cbm_overlaps(r, d, _cbm, closid, exclusive);
> + if (ret)
> + return ret;
if (__rdtgroup_cbm_overlaps(r, d, _cbm, closid, exclusive))
return true;
> +
> + if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp) == 0)
> + return _rdtgroup_cbm_overlaps(r_cdp, d_cdp, _cbm,
> + closid, exclusive);
if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp) < 0)
return false;
return __rdtgroup_cbm_overlaps(r_cpd, d_cdp, _cbm, closid, exclusive);
Makes the whole thing more obvious.
Thanks,
tglx
next prev parent reply other threads:[~2018-10-03 7:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 18:59 [PATCH 0/3] x86/intel_rdt: Fix exclusive mode with CDP resources Reinette Chatre
2018-09-26 18:59 ` [PATCH 1/3] x86/intel_rdt: Introduce utility to obtain CDP peer Reinette Chatre
2018-10-03 6:46 ` Thomas Gleixner
2018-09-26 18:59 ` [PATCH 2/3] x86/intel_rdt: CBM overlap should also check for overlap with " Reinette Chatre
2018-10-03 7:02 ` Thomas Gleixner [this message]
2018-10-03 18:16 ` Reinette Chatre
2018-10-03 19:43 ` Thomas Gleixner
2018-10-03 19:51 ` Reinette Chatre
2018-09-26 18:59 ` [PATCH 3/3] x86/intel_rdt: Fix initial allocation to consider CDP Reinette Chatre
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