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Wysocki" , Jonathan Corbet , Salvatore Bonaccorso , Pawan Gupta , Mauro Carvalho Chehab , Daniel Lezcano , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH] timers/nohz: introduce nohz_full_aggressive In-Reply-To: Message-ID: <2161b8c0-b08c-7bf7-4c99-3bb89ca44ad8@linutronix.de> References: <20230507090700.18470-1-andrea.righi@canonical.com> <20230507100852.54a354ca@rorschach.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 7 May 2023, Andrea Righi wrote: > On Sun, May 07, 2023 at 10:08:52AM -0400, Steven Rostedt wrote: > > > > [ Added Anna-Maria who is doing some timer work as well ] > > > > On Sun, 7 May 2023 11:07:00 +0200 > > Andrea Righi wrote: > > > > Now, I think what is really happening here is that you are somewhat > > simulating the results that Anna-Maria has indirectly. That is, you > > just prevent an idle CPU from waking up to handle interrupts when not > > needed. > > > > Anna-Maria, > > > > Do you have some patches that Andrea could test with? > > > > Thanks, > > > > -- Steve > > Thanks for looking at this (and I'm happy to help Anna-Maria with any > test). I posted v6 of the queue - but forgot to add you to cc list. Here is the current version: https://lore.kernel.org/lkml/20230510072817.116056-1-anna-maria@linutronix.de/ I have to mention, that there is still the issue with the fair scheduler which wakes up the CPU where the process_timeout() timer was enqueued, because it assumes that context is still cache hot. Thanks, Anna-Maria