Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 1 May 2018 22:55:03 -0500
From:   Kim Phillips <kim.phillips@arm.com>
To:     Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <mathieu.poirier@linaro.org>,
        <mike.leach@linaro.org>, <robert.walker@arm.com>,
        <mark.rutland@arm.com>, <will.deacon@arm.com>,
        <robin.murphy@arm.com>, <sudeep.holla@arm.com>,
        <frowand.list@gmail.com>, <robh@kernel.org>, <john.horley@arm.com>
Subject: Re: [PATCH v2 21/27] coresight: Convert driver messages to dev_dbg
Message-Id: <20180501225503.a55fb963795afb40163f3763@arm.com>
In-Reply-To: <1525165857-11096-22-git-send-email-suzuki.poulose@arm.com>
References: <1525165857-11096-1-git-send-email-suzuki.poulose@arm.com>
        <1525165857-11096-22-git-send-email-suzuki.poulose@arm.com>
Organization: Arm
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, 1 May 2018 10:10:51 +0100
Suzuki K Poulose <suzuki.poulose@arm.com> wrote:

> Convert component enable/disable messages from dev_info to dev_dbg.
> This is required to prevent LOCKDEP splats when operating in perf
> mode where we could be called with locks held to enable a coresight

Can we see the splats?  Doesn't lockdep turn itself off if it starts
triggering too many splats?

> path. If someone wants to really see the messages, they can always
> enable it at runtime via dynamic_debug.

Won't the splats still occur when the messages are enabled with
dynamic_debug?

So in effect this patch only tries to mitigate the splats, all the
while making things harder for regular users that now have to recompile
their kernels, in exchange for a very small convenience for kernel
developers that happen to see a splat or two with DEBUG_LOCKDEP set?

Not the greatest choice...How about moving the dev_infos outside of the
locks instead?

Thanks,

Kim