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charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: riel@surriel.com On Wed, 2025-04-16 at 14:44 +0200, Peter Zijlstra wrote: > On Tue, Apr 15, 2025 at 10:02:35AM +0200, Peter Zijlstra wrote: > > On Mon, Apr 14, 2025 at 03:57:42PM -0400, Rik van Riel wrote: > > > On Wed, 2025-04-02 at 10:22 +0200, Peter Zijlstra wrote: > > > >=20 > > > > Please confirm what the reason for overflow is. > > > >=20 > > > Running a large enough sample size has its benefits. > > >=20 > > > We have hit 3 out of the 4 warnings below. > > >=20 > > > The only one we did not hit is the cfs_rq->avg_load !=3D avg_load > > > warning. > >=20 > > Fair enough, that one really isn't hard. > >=20 > > > Most of the time we seem to hit the warnings from the > > > code that removes tasks from the runqueue,=20 > >=20 > > *blink*.. >=20 > Which warning is getting hit on removal? The avg_vruntime mismatch? >=20 > Also, which removal path? schedule()'s block path, or migration like? The most common warning by far, hitting about 90% of the time we hit anything in avg_vruntime_validate is the WARN_ON_ONCE(cfs_rq->avg_vruntime !=3D vruntime) The most common code path to getting there, covering about 85% of the cases: avg_vruntime_validate avg_vruntime_sub __dequeue_entity set_next_entity pick_task_fair pick_next_task_fair __pick_next_task pick_next_task __schedule schedule --=20 All Rights Reversed.