linux-kernel - Re: [RFC PATCH] perf/stat: Add --disable-hwdt

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Message-ID: <20170206124116.7jmrmufthqtnd3dc@pd.tnic>
Date:   Mon, 6 Feb 2017 13:41:16 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Robert Richter <rric@...nel.org>,
        Vince Weaver <vince@...ter.net>,
        lkml <linux-kernel@...r.kernel.org>
Subject: Re: [RFC PATCH] perf/stat: Add --disable-hwdt

On Mon, Feb 06, 2017 at 01:22:31PM +0100, Ingo Molnar wrote:
> Looks sensible, and I'd in fact make this the new default behavior (if root runs 
> perf stat) - i.e. add a flag to re-enable it, for the rare case where we want to 
> debug a hard deadlock while running perf stat ...

I'd probably only need to save the previous state, in case it was
disabled for whatever reason.

So actually, I'll make it so that we restore the previous state at exit.
Whatever it was. But while perf stat runs as root, we will disable it by
default.

/me scratches head a bit...

Oh ok, even better - no need for a cmdline option then.

Or does it *ever* make sense to have watchdog running *while* perf stat
runs too?

Because if it doesn't, turning it off by default *if* it was enabled

	[ should be, we do enable HW WDT by default ]

and restoring it should be the proper thing to do. Without cmdline
option.

Thanks!

-- 
Regards/Gruss,
    Boris.

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