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Date:   Wed, 15 May 2019 11:52:57 -0700
From:   Sultan Alsawaf <sultan@kerneltoast.com>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Oleg Nesterov <oleg@redhat.com>,
        Christian Brauner <christian@brauner.io>,
        Daniel Colascione <dancol@google.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Tim Murray <timmurray@google.com>,
        Michal Hocko <mhocko@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arve =?iso-8859-1?B?SGr4bm5lduVn?= <arve@android.com>,
        Todd Kjos <tkjos@android.com>,
        Martijn Coenen <maco@android.com>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "open list:ANDROID DRIVERS" <devel@driverdev.osuosl.org>,
        linux-mm <linux-mm@kvack.org>,
        kernel-team <kernel-team@android.com>,
        Andy Lutomirski <luto@amacapital.net>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Kees Cook <keescook@chromium.org>,
        Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [RFC] simple_lmk: Introduce Simple Low Memory Killer for Android
Message-ID: <20190515185257.GC2888@sultan-box.localdomain>
References: <20190507021622.GA27300@sultan-box.localdomain>
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 <20190509155646.GB24526@redhat.com>
 <20190509183353.GA13018@sultan-box.localdomain>
 <20190510151024.GA21421@redhat.com>
 <20190513164555.GA30128@sultan-box.localdomain>
 <20190515145831.GD18892@redhat.com>
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On Wed, May 15, 2019 at 02:32:48PM -0400, Steven Rostedt wrote:
> I'm confused why you did this?

Oleg said that debug_locks_off() could've been called and thus prevented
lockdep complaints about simple_lmk from appearing. To eliminate any possibility
of that, I disabled debug_locks_off().

Oleg also said that __lock_acquire() could return early if lock debugging were
somehow turned off after lockdep reported one bug. To mitigate any possibility
of that as well, I threw in the BUG_ON() for good measure.

I think at this point it's pretty clear that lockdep truly isn't complaining
about simple_lmk's locking pattern, and that lockdep's lack of complaints isn't
due to it being mysteriously turned off...

Sultan