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Message-ID: <20250512145613.eD3DUEa8@linutronix.de> References: <20250501032718.65476-1-alexei.starovoitov@gmail.com> <20250501032718.65476-4-alexei.starovoitov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250501032718.65476-4-alexei.starovoitov@gmail.com> X-Rspamd-Queue-Id: EFF06A0009 X-Stat-Signature: 6o55m3xetuwruq5ypucw3deoe1ezxzip X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1747061776-825006 X-HE-Meta: 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 X78eIHe0 WhdYifoNpWF6rCUJv7me2hLDMrvFk5Jv2+BkRoPsvoMy7yaRedqGXhujFmZ6uKc25jzwNPYB8edplrn7PilgFZ2lJ6Bm/wzM9Vag3HIpQ1bMXWpbp7fYSuEW9M9z3XAIKf7jupRajfPvvgK0FzPIYAe66yZjEV5cjBk6fO7fcwzziNGl9NJakc9typ1X/cmheviGvlz7G7R0K80fSID8UQJjfoOTbNSfmr4kPj3cIeppmdPC7WW4Ys1HIOhi3ZUNNOqqXnxNkHXj5IjXDAEEek1GFGg6sXCR62F8QBNke36zMImxTXO+f4TgTgQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2025-04-30 20:27:15 [-0700], Alexei Starovoitov wrote: > --- a/include/linux/local_lock_internal.h > +++ b/include/linux/local_lock_internal.h > @@ -285,4 +288,9 @@ do { \ > __local_trylock(lock); \ > }) > > +/* migration must be disabled before calling __local_lock_is_locked */ > +#include "../../kernel/locking/rtmutex_common.h" > +#define __local_lock_is_locked(__lock) \ > + (rt_mutex_owner(&this_cpu_ptr(__lock)->lock) == current) So I've been looking if we really need rt_mutex_owner() or if rt_mutex_base_is_locked() could do the job. Judging from the slub-free case, the rt_mutex_base_is_locked() would be just fine. The alloc case on the other hand probably not so much. On the other hand since we don't accept allocations from hardirq or NMI the "caller == owner" case should never be observed. Unless buggy & debugging and this should then also be observed by lockdep. Right? If there is another case where recursion can be observed and need to be addressed I would prefer to move the function (+define) to include/linux/rtmutex.h. instead of doing this "../../ include". > #endif /* CONFIG_PREEMPT_RT */ Sebastian