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McKenney" Cc: Valentin Schneider , Linux Kernel Mailing List , linux-mm@kvack.org, rcu@vger.kernel.org, the arch/x86 maintainers , linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , "Peter Zijlstra (Intel)" , Arnaldo Carvalho de Melo , Josh Poimboeuf , Paolo Bonzini , Arnd Bergmann , Frederic Weisbecker , Jason Baron , Steven Rostedt , Ard Biesheuvel , Sami Tolvanen , "David S. Miller" , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Mathieu Desnoyers , Mel Gorman , Andrew Morton , Masahiro Yamada , Han Shen , Rik van Riel , Jann Horn , Dan Carpenter , Oleg Nesterov , Juri Lelli , Clark Williams , Yair Podemsky , Marcelo Tosatti , Daniel Wagner , Petr Tesarik , Shrikanth Hegde Subject: Re: [PATCH v7 00/31] context_tracking,x86: Defer some IPIs until a user->kernel transition In-Reply-To: <1a911310-4ca5-45a4-b9bf-5f37c6ab238e@app.fastmail.com> References: <20251114150133.1056710-1-vschneid@redhat.com> <89398bdf-4dad-4976-8eb9-1e86032c8794@paulmck-laptop> <1a911310-4ca5-45a4-b9bf-5f37c6ab238e@app.fastmail.com> Date: Fri, 14 Nov 2025 21:06:34 +0100 Message-ID: <87zf8o9y5x.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 2379E2000D X-Stat-Signature: rq99itoyfnps3rq6nq8ehcycwngk53ie X-HE-Tag: 1763150797-476132 X-HE-Meta: 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 un+YRWBu U3xzMRXlwa+wBsg699IP/2Kp2jiiOk89PLc4UXppMU/6FkgMdFQ7FV02SlGElgLsAygPHf+eo/khti75lXmBO8kovx/ul4Lm/BSMN/WUg/18+KG6Et9x8Qvy1LGr6AeQrvaxZKMomhBflAL0C2LpkfqQFqT3PtqAewGXuY+9Bl4/8TRgXj9U2Qx89FyMBQNPecdZRmNvBF6georUFJOBnKhEsOrwzhMF2iz40wD5Ji/GblMpnq4C0bqUWYWeLOsJ3Ats6u+WkaEtemEA= 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 Fri, Nov 14 2025 at 10:45, Andy Lutomirski wrote: > But I did that test on a machine that would absolutely benefit from > the IPI suppression that the OP is talking about here, and I think it > would be really quite nice if a default distro kernel with a more or > less default distribution could be easily convinced to run a user > thread without interrupting it. It's a little bit had that NO_HZ_FULL > is still an exotic non-default thing, IMO. Feel free to help with getting it over the finish line. Feeling sad/bad (or whatever you wanted to say with 'had') does not change anything as you should know :) Thanks, tglx