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Wysocki" , Greg Kroah-Hartman , Danilo Krummrich , Zenghui Yu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Kayra Cizmeci , stable@kernel.org Subject: Re: [PATCH v2 1/6] sched/cache: Keep nr_pref_llc_running in the runnable domain Message-ID: <20260922082814.GX4121339@noisy.programming.kicks-ass.net> References: <06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com> <20260922072205.GV4121339@noisy.programming.kicks-ass.net> <65ee9df8-2422-4d1a-80d6-41ac51979da1@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <65ee9df8-2422-4d1a-80d6-41ac51979da1@intel.com> X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: BCA2B1C0008 X-Stat-Signature: zpta3jinmaen58ibpc9kmzruknqpbd95 X-Rspam-User: X-HE-Tag: 1790065707-413818 X-HE-Meta: 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 zEfJ//D8 u4CEpeyFYi/N4Q321o+pCiZQtNSd6odWUwT8anGYb7ZahkOQjqmUu4VLEro3F3L+GdpzXA2AuQBlzmBUJ9hqLiUlvFYOxp1tSiGFzQHl1UcydS1QS/f2mBVLVOFzx+GfyT2mnI5pZC/xEWATNPu7aOritG205daZsI2zN+HIg8j+KqSiXAtUDYkf0mVJVdnHUIjhKnWx/B4NdBobJmlAcXRugmWmPocEIsythXQYg6TceVqFXg/3exMOER9ljyszr35Old+1Cn2+dKya69unmcitLcRtwtFSmTTTCsEDKtAo1ezdSgFYguhR9biwM6/SmKEYTrNjxovqYfxWWhQ2AghEUjVs0q/DBZTiTv+AxiQ3pbzA= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Sep 22, 2026 at 04:25:14PM +0800, Chen, Yu C wrote: > Hi Peter, > > On 9/22/2026 3:22 PM, Peter Zijlstra wrote: > > On Mon, Sep 21, 2026 at 05:37:22PM -0700, Tim Chen wrote: > > > @@ -6395,15 +6429,27 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq); > > > static void set_delayed(struct sched_entity *se) > > > { > > > - se->sched_delayed = 1; > > > - > > > /* > > > * Delayed se of cfs_rq have no tasks queued on them. > > > * Do not adjust h_nr_runnable since __dequeue_task() > > > * will account it for blocked tasks. > > > + * > > > + * This check can be removed because when flat pick > > > + * patches get merged as only task can get delayed, > > > + * same for clear_delayed(). > > > */ > > > - if (!entity_is_task(se)) > > > + if (!entity_is_task(se)) { > > > + se->sched_delayed = 1; > > > return; > > > + } > > > > This is dead code. In Linus' tree, where this will be applied, this can > > never happen. A possible backport of this fix however will need to take > > care. > > > > Would you prefer that we create a separate patch to remove entity_is_task() > for Linus's tree (so that the current patch can be backported, since > cache-aware > scheduling was merged before flat task-pickup)? Nah, I munged it in with a few changes (I removed that cache-sched.c file) and it seems to build. See queue.git/sched/urgent. I'll queue up a patch for sched/core that removes some of that -- if I don't forget and all that.