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[86.130.134.87]) by smtp.gmail.com with ESMTPSA id j18-20020a5d4492000000b0022f864164edsm15009276wrq.6.2022.10.19.17.15.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 17:15:03 -0700 (PDT) Date: Thu, 20 Oct 2022 01:15:01 +0100 From: Qais Yousef To: John Stultz Cc: Alexander Gordeev , LKML , Connor O'Brien , John Dias , Rick Yiu , John Kacur , Qais Yousef , Chris Redpath , Abhijeet Dharmapurikar , Peter Zijlstra , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Thomas Gleixner , kernel-team@android.com, "J . Avila" Subject: Re: [PATCH RFC v4 2/3] sched: Avoid placing RT threads on cores handling long softirqs Message-ID: <20221020001501.7qbqd5r4gvw3enjs@airbuntu> References: <20221003232033.3404802-1-jstultz@google.com> <20221003232033.3404802-3-jstultz@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS 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 10/19/22 15:09, John Stultz wrote: > I fret there are some edge cases where on the target cpu softirqs > might be pending but ksoftirqd isn't running yet maybe due to a > lowish-prio rt task - such that the cpu could still be considered a > good target. But this seems a bit of a stretch. Could using ksoftirqd_running() instead help with robustness here? Cheers -- Qais Yousef