linux-kernel - Re: [patch/rfc] perf on raspberry-pi without overflow interrupt

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: <alpine.DEB.2.10.1401161209280.1996@vincent-weaver-1.um.maine.edu>
Date:	Thu, 16 Jan 2014 12:13:10 -0500 (EST)
From:	Vince Weaver <vincent.weaver@...ne.edu>
To:	Peter Zijlstra <peterz@...radead.org>
cc:	Vince Weaver <vincent.weaver@...ne.edu>,
	Will Deacon <will.deacon@....com>,
	Chad Paradis <chad.paradis@...t.maine.edu>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Stephane Eranian <eranian@...il.com>
Subject: Re: [patch/rfc] perf on raspberry-pi without overflow interrupt

On Tue, 14 Jan 2014, Peter Zijlstra wrote:

> On Mon, Jan 13, 2014 at 11:55:17PM -0500, Vince Weaver wrote:

> > I don't see an existing pmu capabilities struct... or do you mean
> > coming up with one?
> 
> Yeah, adding one.

So would it be a struct, or just an integer with flags?

> > Would it only hold an "overflow_interrupt_available" flag, or are
> > there other generic capabilities it would be handy to know about?
> 
> Possible (other) flags could be:
> 
>   PMU_HAS_INT      -- would allow sampling events
>   PMU_HAS_PRECISE  -- would allow any ::precise value
>   PMU_HAS_FILTER   -- would allow all os/user/etc. flags

should we export these to userspace somehow?

It would be handy to be able to tell you're getting EOPNOTSUP because
PMU_HAS_INT is not set for your pmu, rather than trying to guess why 
things are failing.

Vince
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/