From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from va-1-114.ptr.blmpb.com (va-1-114.ptr.blmpb.com [209.127.230.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 112D2380FDA for ; Fri, 12 Jun 2026 02:20:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.127.230.114 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781230804; cv=none; b=eVyDZKgUmgEkA0j9zaQbEoSyz6kjT9qCUFrLmK3hKsItoASehheMJX2vl04CyEoWKMujdtp6+jHAxyS7K70N91bbhFIrwO1UPA09VJazbPgaxNphYw3fr0MqKr2540M+26QiYxbBDs938WHX0LT9iCKf0vjTkEpqvgX+YOZ/o5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781230804; c=relaxed/simple; bh=B13Zu6hwKikiAJTfKxLnIVtkYrvcjxjvlRqoioRKlco=; h=To:Date:Message-Id:Mime-Version:Subject:References: Content-Disposition:In-Reply-To:Cc:From:Content-Type; b=gwgmXh1LqgsZwQfeUvwkQAQaVczaP8jufBzJtBBSDMyJr+XeJWNqWaNbxz70knOR6X+FV4E4U1JaMoJUZ4TmEjW0RJxNfulMjoHZuzF/HtfsoZ3ulS49c9ojUxrtOb5XbGo6sm0DaphcmeR8BFLvuD2gO6ggz12HdMylTucOG1o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=KUOXC9kB; arc=none smtp.client-ip=209.127.230.114 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="KUOXC9kB" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=2212171451; d=bytedance.com; t=1781230797; h=from:subject: mime-version:from:date:message-id:subject:to:cc:reply-to:content-type: mime-version:in-reply-to:message-id; bh=WtjGJKpS2uRnIM7fgA/fkrkLzM5ulmaNMDMUp+8agkQ=; b=KUOXC9kBbmBbBXf5hBPV2gi5frKcwnOzF8BBh/6/mK+wmSmCgnkqTJFc0pCy+9CbJh8pEy DAk1b+DjAVXWfmX5Dd5ijTtEBxgVadCE4OBw3SaeqPJOEZFRJf4cI5Qx3JWcCmpsTnM7o7 zZZFznmFuTVUvsPi6Sh+nX5hg4Qm3Sk3SrVR9LiMs8YhA7P592Pt7LyO7tYVO5EEvXBPMX ikKm6B8UHRh0mLZNWkag9ky7IEd+gW0iAepZ+Rtd/lYuwIxZ59tvZ+5e8hE+MhNF0Zvxuw k1o6rgBBIcPUq2MKSHstlVQmcvAiNjAWUZl1IYkU39pN0ZFdvYtdDRahnuxIdQ== To: "Peter Zijlstra" Date: Fri, 12 Jun 2026 10:19:21 +0800 Message-Id: <20260612021921.GA2551535@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [PATCH v2 08/10] sched/fair: Add newidle balance to pick_task_fair() References: <20260511113104.563854162@infradead.org> <20260511120627.944705718@infradead.org> <20260603095108.GA1684319@bytedance.com> <20260611113219.GG187714@noisy.programming.kicks-ass.net> Content-Disposition: inline In-Reply-To: <20260611113219.GG187714@noisy.programming.kicks-ass.net> Cc: , , , , , , , , , , , , , , , , , , From: "Aaron Lu" X-Original-From: Aaron Lu Content-Type: text/plain; charset=UTF-8 X-Lms-Return-Path: Hi Peter, On Thu, Jun 11, 2026 at 01:32:19PM +0200, Peter Zijlstra wrote: > > Aaron, > > Sorry I failed to notice this email earlier. > Never mind. > On Wed, Jun 03, 2026 at 05:51:08PM +0800, Aaron Lu wrote: > > > I applied below diff and the problem is gone: > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 5f48af700fd44..942a543af3e54 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -9897,6 +9897,9 @@ static struct task_struct *pick_task_fair(struct rq *rq, struct rq_flags *rf) > > return p; > > > > idle: > > + if (sched_core_enabled(rq)) > > + return NULL; > > + > > new_tasks = sched_balance_newidle(rq, rf); > > if (new_tasks < 0) > > return RETRY_TASK; > > > > Right, this is the safe patch and restores pick_task_fair() to its > previous status (for core-sched). > > Since people are hitting this problem, I'm going to merge it as below. > I've presumed your SoB, please let me know if that's a problem. No problem. > > I think I'm going to try and move newidle into sched_class::balance / > balance_fair(), but I'll do that next cycle. I'll surely test it then. Best regards, Aaron