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McKenney" , Steven Rostedt , Masami Hiramatsu , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Andy Lutomirski , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Josh Poimboeuf , Jason Baron , Kees Cook , Sami Tolvanen , Ard Biesheuvel , Nicholas Piggin , Juerg Haefliger , Nicolas Saenz Julienne , "Kirill A. Shutemov" , Nadav Amit , Dan Carpenter , Chuang Wang , Yang Jihong , Petr Mladek , "Jason A. Donenfeld" , Song Liu , Julian Pidancet , Tom Lendacky , Dionna Glaze , Thomas =?iso-8859-1?Q?Wei=DFschuh?= , Juri Lelli , Marcelo Tosatti , Yair Podemsky , Daniel Wagner , Petr Tesarik Subject: Re: [RFC PATCH v3 04/15] rcu: Add a small-width RCU watching counter debug option Message-ID: <20241120145049.GI19989@noisy.programming.kicks-ass.net> References: <20241119153502.41361-1-vschneid@redhat.com> <20241119153502.41361-5-vschneid@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241119153502.41361-5-vschneid@redhat.com> X-Rspamd-Server: rspam10 X-Stat-Signature: hi7kpkr8bso3f7mdpbqa1pd958thdi49 X-Rspamd-Queue-Id: F0DE68001D X-Rspam-User: X-HE-Tag: 1732114188-973040 X-HE-Meta: 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 /OIC0ghP 0Rd0ptVXtRpClfiEtso8kHCYGZxmUJhVM14vsaUbIl8Bdq6jsTJhMySbOOuOUjgxbmvj/zLjkhtiD2koW9KL5gb7vhbJ9EdbsHppExuRR06vsYcOU+56xo3MabMKQpLGlIiv0SYabflEGeSrQ+FyXeBXuXFnbQ7ghdJ1TSDPmiTUNcrWVrfaa21eHtfsZuuYMLe2FQmNLab8UevCmOwrV+Dn39iuR7bx968Fq6ndxNE5h5jcjnLE9z0zdXpe5zhKPA7HIa5b4t8dR/xY= 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 Tue, Nov 19, 2024 at 04:34:51PM +0100, Valentin Schneider wrote: > A later commit will reduce the size of the RCU watching counter to free up > some bits for another purpose. Paul suggested adding a config option to > test the extreme case where the counter is reduced to its minimum usable > width for rcutorture to poke at, so do that. > > Make it only configurable under RCU_EXPERT. While at it, add a comment to > explain the layout of context_tracking->state. Note that this means it will get selected by allyesconfig and the like, is that desired? If no, depends on !COMPILE_TEST can help here.