Messages in this thread Patch in this message | | | Date | Wed, 18 Oct 2017 08:39:46 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] rcu: do not include rtmutex_common.h unconditionally |
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On Wed, Oct 18, 2017 at 10:34:36AM +0200, Sebastian Andrzej Siewior wrote: > Since commit bcda31a26594 ("rcu: Suppress lockdep false-positive > ->boost_mtx complaints") the rtmutex_common.h is included > unconditionally. This break CONFIG_FUTEX=n configs which do not have > CONFIG_RT_MUTEX enabled which leads to the lack of certain members in > task_struct which are accessed in rtmutex_common.h as reported by the kbuild > test robot: > | In file included from include/uapi/linux/stddef.h:1:0, > | from include/linux/stddef.h:4, > | from include/uapi/linux/posix_types.h:4, > | from include/uapi/linux/types.h:13, > | from include/linux/types.h:5, > | from kernel/rcu/tree.c:30: > | kernel/rcu/../locking/rtmutex_common.h: In function 'task_has_pi_waiters': > |>> kernel/rcu/../locking/rtmutex_common.h:62:26: error: 'struct task_struct' has no member named 'pi_waiters'; did you mean 'cpu_timers'? > > among other things. > I move the include back to the RCU_BOOST ifdef and add there the > rt_mutex_futex_unlock define like we already have it for rt_mutex_owner > for the same reason. > While at it, I remove the second rtmutex_common.h include within the > RCU_BOOST block because one of those is enough. > > Fixes: bcda31a26594 ("rcu: Suppress lockdep false-positive ->boost_mtx complaints") > Reported-by: kbuild test robot <fengguang.wu@intel.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Thank you very much, hand-applied as a preparatory patch for "Suppress lockdep false-positive ->boost_mtx complaints", please see below.
What I don't understand is why 0day test robot didn't complain about my copy of the exact same patch. Or maybe it did and I fat-fingered it? Except that I have gotten "BUILD SUCCESS" reports for commits including that one.
Ah well, hopefully all is well that ends well...
> --- > On 2017-10-18 09:32:09 [+0200], To Paul E. McKenney wrote: > > I will > > look at this once I made some slides… > > slides, who needs those anyway…
Best of everything on the presentation, and hope that I didn't mess you up too badly.
Thanx, Paul
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commit a06f537e75ea0a9e81245ede1b97bb3a5762b81b Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Wed Oct 18 08:33:44 2017 -0700
rcu: do not include rtmutex_common.h unconditionally This commit adjusts include files and provides definitions in preparation for suppressing lockdep false-positive ->boost_mtx complaints. Without this preparation, architectures not supporting rt_mutex will get build failures. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index fed95fa941e6..969eae45f05d 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -54,6 +54,7 @@ DEFINE_PER_CPU(char, rcu_cpu_has_work); * This probably needs to be excluded from -rt builds. */ #define rt_mutex_owner(a) ({ WARN_ON_ONCE(1); NULL; }) +#define rt_mutex_futex_unlock(x) WARN_ON_ONCE(1) #endif /* #else #ifdef CONFIG_RCU_BOOST */ @@ -911,8 +912,6 @@ void exit_rcu(void) #ifdef CONFIG_RCU_BOOST -#include "../locking/rtmutex_common.h" - static void rcu_wake_cond(struct task_struct *t, int status) { /*
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