Re: [Xen-devel] [PATCH v5 3/4] xen/rcu: add assertions to debug build

[Jürgen Groß <jgross@xxxxxxxx>]

On 12.03.20 09:28, Juergen Gross wrote:
> Xen's RCU implementation relies on no softirq handling taking place
> while being in a RCU critical section. Add ASSERT()s in debug builds
> in order to catch any violations.
>
> For that purpose modify rcu_read_[un]lock() to use a dedicated percpu
> counter instead of preempt_[en|dis]able() as this enables to test
> that condition in __do_softirq() (ASSERT_NOT_IN_ATOMIC() is not
> usable there due to __cpu_up() calling process_pending_softirqs()
> while holding the cpu hotplug lock).
>
> Dropping the now no longer needed #include of preempt.h in rcupdate.h
> requires adding it in some sources.
>
> While at it switch the rcu_read_[un]lock() implementation to static
> inline functions instead of macros.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Depending on the acceptance of my just sent series for fixing
preemption disabling in locks I might send a fixup to this patch, too,
re-adding preempt_disable() to rcu_read_lock().


Juergen

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel