Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers

From	"J. R. Okajima" <hooanon05g@gmail.com>
Newsgroups	linux.kernel
Subject	Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers
Date	2017-04-30 08:10 +0200
Message-ID	<tBQdr-85f-3@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

Show all headers | View raw

Hello,

Since v4.11-rc7 I can see the workqueue stops on my development/test system.
Git-bisecting tells me the suspicious commit is
	c053b5a 2017-04-11 drm/i915: Don't call synchronize_rcu_expedited under struct_mutex

I am not sure whether this is the real cause or not of my problem, but I
have a question.
By the commit, the shrinker handlers ->scan_objects() and
->count_objects() both calls synchronize_rcu_expedited()
unconditionally. Is it a legal RCU bahavour?

I know dev->struct_mutex is unlocked now, but before the commit, these
two handlers were not calling synchronize_rcu_expedited().


J. R. Okajima

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers "J. R. Okajima" <hooanon05g@gmail.com> - 2017-04-30 08:10 +0200
  Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers Andrea Arcangeli <aarcange@redhat.com> - 2017-04-30 11:50 +0200
    Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers "J. R. Okajima" <hooanon05g@gmail.com> - 2017-05-01 04:10 +0200
      Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers Joonas Lahtinen <joonas.lahtinen@linux.intel.com> - 2017-05-05 11:50 +0200
        Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from  handlers Hugh Dickins <hughd@google.com> - 2017-05-06 00:00 +0200
          Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers Joonas Lahtinen <joonas.lahtinen@linux.intel.com> - 2017-05-08 10:10 +0200
            Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from  handlers Hugh Dickins <hughd@google.com> - 2017-05-10 05:10 +0200
              Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers Joonas Lahtinen <joonas.lahtinen@linux.intel.com> - 2017-05-10 12:00 +0200
              Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers Andrea Arcangeli <aarcange@redhat.com> - 2017-05-10 12:50 +0200
                Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers Joonas Lahtinen <joonas.lahtinen@linux.intel.com> - 2017-05-10 13:10 +0200
        Re: Q. drm/i915 shrinker, synchronize_rcu_expedited() from handlers "J. R. Okajima" <hooanon05g@gmail.com> - 2017-05-06 01:30 +0200

csiph-web