netdev - Re: [RFC PATCH 2/7] core/metricfs: add support for percpu metricfs files

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:   Sat, 8 Aug 2020 07:43:04 +0200
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Jonathan Adams <jwadams@...gle.com>
Cc:     linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        netdev@...r.kernel.org, kvm@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Jim Mattson <jmattson@...gle.com>,
        David Rientjes <rientjes@...gle.com>
Subject: Re: [RFC PATCH 2/7] core/metricfs: add support for percpu metricfs
 files

On Fri, Aug 07, 2020 at 02:29:11PM -0700, Jonathan Adams wrote:
> Add a simple mechanism for exporting percpu data through metricfs.
> The API follows the existing metricfs pattern.  A percpu file is
> defined with:
> 
>     METRIC_EXPORT_PERCPU_INT(name, desc, fn)
>     METRIC_EXPORT_PERCPU_COUNTER(name, desc, fn)
> 
> The first defines a file for exposing a percpu int.  The second is
> similar, but is for a counter that accumulates since boot.  The
> 'name' is used as the metricfs file.  The 'desc' is a description
> of the metric.  The 'fn' is a callback function to emit a single
> percpu value:
> 
>     void (*fn)(struct metric_emitter *e, int cpu);
> 
> The callback must call METRIC_EMIT_PERCPU_INT with the value for
> the specified CPU.
> 
> Signed-off-by: Jonathan Adams <jwadams@...gle.com>
> 
> ---
> 
> jwadams@...gle.com: rebased to 5.6-pre6, renamed funcs to start with
> 	metric_.  This is work originally done by another engineer at
> 	google, who would rather not have their name associated with this
> 	patchset. They're okay with me sending it under my name.
> ---
>  include/linux/metricfs.h | 28 +++++++++++++++++++
>  kernel/metricfs.c        | 58 ++++++++++++++++++++++++++++++++++++----

fs/metricfs/ ?  This isn't a kernel "core" feature.

Or just put it in fs/debugfs/ and tack it along with one of the debugfs
helper functions to make it easier for everyone to use these (if they
actually are valuable.  It's hard to see how this differs from any other
debugfs interface today.

thanks,

greg k-h