Messages in this thread | | | From | Uladzislau Rezki <> | Date | Wed, 15 Jul 2020 21:02:43 +0200 | Subject | Re: [PATCH 1/1] rcu/tree: Drop the lock before entering to page allocator |
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On Wed, Jul 15, 2020 at 08:56:28PM +0200, Sebastian Andrzej Siewior wrote: > On 2020-07-15 20:35:37 [+0200], Uladzislau Rezki (Sony) wrote: > > @@ -3306,6 +3307,9 @@ kvfree_call_rcu_add_ptr_to_bulk(struct kfree_rcu_cpu *krcp, void *ptr) > > if (IS_ENABLED(CONFIG_PREEMPT_RT)) > > return false; > > > > + preempt_disable(); > > + krc_this_cpu_unlock(*krcp, *flags); > > Now you enter memory allocator with disabled preemption. This isn't any > better but we don't have a warning for this yet. > Please elaborate why it is not allowed? Consider the code:
<snip> spin_lock(); __get_free_page(GFP_NOWAIT | __GFP_NOWARN); spin_unlock(); <snip>
Also, please note we do it for regular kernel.
> > What happened to the part where I asked for a spinlock_t? > What do you mean?
-- Vlad Rezki
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