Re: [PATCH] context_tracking: Restore previous state in schedule_user

[Dave Jones]

On Wed, Dec 03, 2014 at 04:04:31PM -0800, Andy Lutomirski wrote:
 > On Wed, Dec 3, 2014 at 3:58 PM, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote:
 > > On Wed, Dec 03, 2014 at 03:18:41PM -0800, Andy Lutomirski wrote:
 > >> It appears that some SCHEDULE_USER (asm for schedule_user) callers
 > >> in arch/x86/kernel/entry_64.S are called from RCU kernel context,
 > >> and schedule_user will return in RCU user context.  This causes RCU
 > >> warnings and possible failures.
 > >>
 > >> This is intended to be a minimal fix suitable for 3.18.
 > >>
 > >> Reported-by: Dave Jones <davej@xxxxxxxxxx>
 > >> Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
 > >> Cc: Frédéric Weisbecker <fweisbec@xxxxxxxxx>
 > >> Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
 > >> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
 > >
 > > Ah, we sent it about at the same time :-)
 > >
 > > Might be too late for 3.18 though because it's not a regression.

Wait, so how come that trace didn't start showing up until recently ?

	Dave

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