• Ingo Molnar's avatar
    locking/lockdep: Disable cross-release features for now · b483cf3b
    Ingo Molnar authored
    Johan Hovold reported a big lockdep slowdown on his system, caused by lockdep:
    
    > I had noticed that the BeagleBone Black boot time appeared to have
    > increased significantly with 4.14 and yesterday I finally had time to
    > investigate it.
    >
    > Boot time (from "Linux version" to login prompt) had in fact doubled
    > since 4.13 where it took 17 seconds (with my current config) compared to
    > the 35 seconds I now see with 4.14-rc4.
    >
    > I quick bisect pointed to lockdep and specifically the following commit:
    >
    >	28a903f6 ("locking/lockdep: Handle non(or multi)-acquisition of a crosslock")
    
    Because the final v4.14 release is close, disable the cross-release lockdep
    features for now.
    Bisected-by: default avatarJohan Hovold <johan@kernel.org>
    Debugged-by: default avatarJohan Hovold <johan@kernel.org>
    Reported-by: default avatarJohan Hovold <johan@kernel.org>
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: Byungchul Park <byungchul.park@lge.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Tony Lindgren <tony@atomide.com>
    Cc: kernel-team@lge.com
    Cc: linux-arm-kernel@lists.infradead.org
    Cc: linux-mm@kvack.org
    Cc: linux-omap@vger.kernel.org
    Link: http://lkml.kernel.org/r/20171014072659.f2yr6mhm5ha3eou7@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    b483cf3b
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