Messages in this thread | | | Date | Thu, 28 Aug 2014 11:16:49 +0530 | From | Amit Shah <> | Subject | Re: [PATCH] rcu: Make nocb leader kthreads process pending callbacks after spawning |
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On (Wed) 27 Aug 2014 [16:43:40], Pranith Kumar wrote: > The nocb callbacks generated before the nocb kthreads are spawned are > enqueued in the nocb queue for later processing. Commit fbce7497ee5af ("rcu: > Parallelize and economize NOCB kthread wakeups") introduced nocb leader kthreads > which checked the nocb_leader_wake flag to see if there were any such pending > callbacks. A case was reported in which newly spawned leader kthreads were not > processing the pending callbacks as this flag was not set, which led to a boot > hang. > > The following commit ensures that the newly spawned nocb kthreads process the > pending callbacks by allowing the kthreads to run immediately after spawning > instead of waiting. This is done by inverting the logic of nocb_leader_wake > tests to nocb_leader_sleep which allows us to use the default initialization of > this flag to 0 to let the kthreads run. > > Reported-by: Amit Shah <amit.shah@redhat.com> > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> > Link: http://www.spinics.net/lists/kernel/msg1802899.html > --- > kernel/rcu/tree.h | 2 +- > kernel/rcu/tree_plugin.h | 24 ++++++++++++------------ > 2 files changed, 13 insertions(+), 13 deletions(-)
I'd have split this into two patches: one for the variable rename and one for fixing the bug.
However, the backport Paul posted does work fine for me on master, so you can add my
Tested-by: Amit Shah <amit.shah@redhat.com>
Thanks,
Amit
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