From: Thomas Gleixner <tglx@linutronix.de>
To: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: vikas.shivappa@intel.com, linux-kernel@vger.kernel.org,
x86@kernel.org, hpa@zytor.com, mingo@kernel.org,
peterz@infradead.org, ravi.v.shankar@intel.com,
tony.luck@intel.com, fenghua.yu@intel.com, andi.kleen@intel.com
Subject: Re: [PATCH 6/8] x86/intel_rdt/mba: Add info directory files for MBA
Date: Wed, 1 Mar 2017 17:05:06 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1703011634560.4005@nanos> (raw)
In-Reply-To: <1487361535-9727-7-git-send-email-vikas.shivappa@linux.intel.com>
On Fri, 17 Feb 2017, Vikas Shivappa wrote:
> Add files in info directory for MBA.
> The files in the info directory are as follows :
> - num_closids: max number of closids for MBA which represents the max
> class of service user can configure.
> - min_bw: the minimum memory bandwidth(b/w) values in percentage.
>
> OS maps the b/w percentage values to memory b/w throttle delay values
> and configures them via MSR interface by writing to the QOS_MSRs. These
> delay values can have a linear or nonlinear scale.
>
> - bw_gran: The memory b/w granularity that can be configured.
> For ex: If the granularity is 10% and min_bw is 10, valid bandwidth
> values are 10,20,30...
This is unreadable. It's possible to structure ASCII text cleanly.
x86/rdt: Add info directory files for MBA
The info directory for MBA contains the following files:
num_closids
The maximum number of class of service slots available for MBA
min_bandwidth
The minimum memory bandwidth percentage value
bandwidth_gran
The granularity of the bandwidth control for the particular
hardware in percent. The available bandwidth control steps are:
min_bw + N * bw_gran Intermediate values are rounded to the next
control step available on the hardware.
delay_linear
If set, the control registers take a linear percentage based value
between min_bandwidth and 100 percent.
If not set, the control registers take a power of 2 based value
which is mapped by the kernel to percentage based values.
This file is of pure informational nature and has no influence on
the values which are written to the schemata files. These are
always percentage based.
Note, that this uses the actual file names and not some random
abbreviations thereof. It also documents delay_linear and gets rid of the
implementation details of QOS_MSRs. They are irrelevant here.
And exactly this information wants to go into Documentation/... preferably
in exactly this patch and not in a disconnected one which describes stuff
differently for whatever reasons.
> +static int rdt_min_bw_show(struct kernfs_open_file *of,
> + struct seq_file *seq, void *v)
> +{
> + struct rdt_resource *r = of->kn->parent->priv;
> +
> + seq_printf(seq, "%d\n", r->min_bw);
> +
Can you please get rid of these pointless extra new lines before the
'return 0;' ? They are just eating screen estate and do not make the code
more readable.
> +/* rdtgroup information files for MBE. */
What is MBE?
> +static struct rftype res_mbe_info_files[] = {
Randomizing names make the code more secure or what are you trying to
achieve?
> +void rdt_get_mba_infofile(struct rdt_resource *r)
> +{
> + r->info_files = &res_mbe_info_files[0];
See other mail.
Thanks,
tglx
next prev parent reply other threads:[~2017-03-01 16:25 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-17 19:58 [PATCH 0/8 V2] x86/intel_rdt: Intel Memory bandwidth allocation Vikas Shivappa
2017-02-17 19:58 ` [PATCH 1/8] Documentation, x86: Documentation for Intel Mem b/w allocation Vikas Shivappa
2017-02-17 19:58 ` [PATCH 2/8] x86/intel_rdt/mba: Generalize the naming to get ready for MBA Vikas Shivappa
2017-02-17 19:58 ` [PATCH 3/8] x86/intel_rdt/mba: Memory b/w allocation feature detect Vikas Shivappa
2017-02-17 19:58 ` [PATCH 4/8] x86/intel_rct/mba: Add MBA structures and initialize MBA Vikas Shivappa
2017-03-01 15:24 ` Thomas Gleixner
2017-03-10 21:51 ` Shivappa Vikas
2017-02-17 19:58 ` [PATCH 5/8] x86/intel_rdt: info file support for MBA prepare Vikas Shivappa
2017-03-01 15:34 ` Thomas Gleixner
2017-03-10 22:04 ` Shivappa Vikas
2017-02-17 19:58 ` [PATCH 6/8] x86/intel_rdt/mba: Add info directory files for MBA Vikas Shivappa
2017-03-01 16:05 ` Thomas Gleixner [this message]
2017-03-10 23:26 ` Shivappa Vikas
2017-02-17 19:58 ` [PATCH 7/8] x86/intel_rdt: schemata file support for MBA prepare Vikas Shivappa
2017-03-01 16:24 ` [PATCH 7/8] x86/intel_rdt: schemata file support for MBA prepare\ Thomas Gleixner
2017-03-30 19:05 ` Shivappa Vikas
2017-02-17 19:58 ` [PATCH 8/8] x86/intel_rdt/mba: Add schemata file support for MBA Vikas Shivappa
2017-03-01 16:59 ` Thomas Gleixner
-- strict thread matches above, loose matches on Subject: below --
2017-04-08 0:33 [PATCH 0/8 V4] x86/intel_rdt: Intel Memory bandwidth allocation Vikas Shivappa
2017-04-08 0:33 ` [PATCH 6/8] x86/intel_rdt/mba: Add info directory files for MBA Vikas Shivappa
2017-04-03 21:57 [PATCH 0/8 V3] x86/intel_rdt: Intel Memory bandwidth allocation Vikas Shivappa
2017-04-03 21:57 ` [PATCH 6/8] x86/intel_rdt/mba: Add info directory files for MBA Vikas Shivappa
2017-01-10 19:33 [PATCH 0/8 V1] x86/intel_rdt: Memory b/w Allocation support Vikas Shivappa
2017-01-10 19:33 ` [PATCH 6/8] x86/intel_rdt/mba: Add info directory files for MBA Vikas Shivappa
2017-01-16 14:14 ` Thomas Gleixner
2017-01-18 1:02 ` Shivappa Vikas
2017-01-18 9:08 ` Thomas Gleixner
2017-01-23 19:45 ` Shivappa Vikas
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