linux-kernel - Re: [PATCH v9 1/5] cpufreq: Allow arch_freq_get_on

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]

Message-ID: <20250128081823.o3q6gjcjca5ju3u6@vireshk-i7>
Date: Tue, 28 Jan 2025 13:48:23 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Beata Michalska <beata.michalska@....com>
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-pm@...r.kernel.org, ionela.voinescu@....com,
	sudeep.holla@....com, will@...nel.org, catalin.marinas@....com,
	rafael@...nel.org, sumitg@...dia.com, yang@...amperecomputing.com,
	vanshikonda@...amperecomputing.com, lihuisong@...wei.com,
	zhanjie9@...ilicon.com
Subject: Re: [PATCH v9 1/5] cpufreq: Allow arch_freq_get_on_cpu to return an
 error

On 28-01-25, 09:09, Beata Michalska wrote:
> On Fri, Jan 24, 2025 at 09:03:33AM +0530, Viresh Kumar wrote:
> > On 23-01-25, 22:45, Beata Michalska wrote:
> > > That would mean we are opting for presenting '0' value (whatever that means)
> > > instead of trying alternative ways of getting 'current' frequency ?
> > > This is still the scaling_cur_freq.
> > 
> > A return value of 0 should typically mean something went wrong
> > somewhere and didn't return the right value to us.
> If smth goes wrong, an error should be returned, shoulnd't it?

Right, but what if no error is detected and still a value of 0 is
returned somehow ? That's what I was talking about.

> > - For the print message, I think we should just print the value
> >   instead of UNKNOWN. Let the user / developer decide what to do with
> >   it.
> Are you refering to the x86 show_cpuinfo behaviour altered by this patch ?

Yes

> > - As for trying other mechanism to find the frequency now, maybe you
> >   are right and looking for an alternate way is the right way to go.
> >   And that would be consistent with existing behavior too.
> > 
> That would mean that changes to show_scaling_cur_freq are fine ?

Yes.

-- 
viresh