From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 4425BD531 for ; Thu, 14 May 2026 23:47:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778802462; cv=none; b=WvLPRe+kUM4MJja/XbiqHRYrzT25YwF+zq4kWrfJivMwWkobAXSzlgP1aPMvKqtBnsZdtAKkBd87Mx47b1zpKALWEuy+cMyqQmcA8DYnstumG11bZCmjotARlqdqdZZFgAdHEPpVieZa2jnHhRrjr+z2l7zkyjb0H1dkY2PEyd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778802462; c=relaxed/simple; bh=gZCqLhNeSp9GOwHtVfQawLfSncRsmQVB1zLuiHoQCKw=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=LAj9/6SU5g+8+DxhuxvjWbKMY/C79mbQTznaYKGoeKBN5Ka2T8yWM5bYrVJojMiBi4rwKeFLt13957JaqLi0D3WhU9aMTYGQaZgLiH7Sfimb8w/ljeEyKEc2V4CT//H17YynStEL0xjyxsWWE0gyKwh8DRysLvezi16w2Cmillk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=OAv5XeZY; arc=none smtp.client-ip=209.85.210.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="OAv5XeZY" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-83836443305so4866813b3a.1 for ; Thu, 14 May 2026 16:47:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778802460; x=1779407260; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=YDAjQ2n4L0mhtr1CnAi8SU906RYLes1utprZld2UmS4=; b=OAv5XeZYFu4Mg7T4ZoLmZ/XT+ctRvHC0/JqBO7z3nB1nmH/l1NcBSgB+7D1qtqBpda DO1tsOW/eiC3DE4p5XYtwTi67yesM5Z4TcqUDHVmE3JVvO7SQrMyN97iVq5QjZvu9dkO I1UZGQPOlXyjVdXRKaGc5DyHWf9bdhveR31vOK3/sH+X4kyxSLy0QFUfqPjYEz45Opo/ f8cVEJKD6qGdvtbr8WGKn9hdtbe09JCQy5lnAcAal/iahQFjZycw10dclvxQ76b4MA6v I3n9ILZ3Xw6iBRXJXo80paC+BE2+O0KPL1pJqRdqeDILY1zxfzIrrWaHrlq+Ivrk+Syc 2yBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778802460; x=1779407260; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=YDAjQ2n4L0mhtr1CnAi8SU906RYLes1utprZld2UmS4=; b=e+5BCBs8JLexkjD1CYR2YxzHxTs3dQSA1n19VnWhCNm06/Xiqt8umVshLQ69hfdhNw r0yGRxAUSYYZEaIQS99eu6ZA8xLA6l/o78qvaqqxklze04W1KXviR3oon2ngMk0lGDrB WNNgV2Sbh26cXQuSIP90SEr3RELpfExg6nVxUcbYGB10DehlbQEbM5+yoypNhcxdgLfF H5v+CBEskWguEs10UIfV47vAZnf6ywRCqluUdF/VMDr7exfLU3lsoHyj2sven24juH7W dmdchjBe7s0jdc68/HszcV7xL3Gf89RHddaTSIxk6qHhp/k9dPwVoWTQ2vZdli9022ME QW7g== X-Gm-Message-State: AOJu0YyOQHp+7xoj+aTCAbj9q7YNBnUHO4EYPqy50kpGRIH7+6IcIREP noX36rc2vfIJacpv+15oHg/U3rsw9tIEFEo2UGmW4FgX4E7leyfnD+Efx7x6tbUz6jM6beqR63x dWdQ5M/QiKx/GS42lv0KSzIYz6aC+0e8/cgt31Xdh0gpwXcs8z9HTiXwpbPIQJLr0mkW9H1BjqQ 9egledm5g1Zdf+/1md+8W2iSGs0IQ1VWnHzftHShRIiJvK94xS X-Received: from pfbgd24.prod.google.com ([2002:a05:6a00:8318:b0:82f:9e73:207b]) (user=jstultz job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:94c4:b0:82c:212a:a9b5 with SMTP id d2e1a72fcca58-83f33d52d3cmr1523752b3a.36.1778802460021; Thu, 14 May 2026 16:47:40 -0700 (PDT) Date: Thu, 14 May 2026 23:47:17 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: <20260514234732.3170197-1-jstultz@google.com> Subject: [PATCH] sched: Switch rq->next_class on proxy_resched_idle() From: John Stultz To: LKML Cc: John Stultz , K Prateek Nayak , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Valentin Schneider , kernel-team@android.com Content-Type: text/plain; charset="UTF-8" K Prateek noticed we weren't setting the rq->next_class in proxy_resched_idle(), when I was debugging an issue seen with CONFIG_SCHED_PROXY_EXEC and some of Peter's new patches, and suggested this fix. So set rq->next_class when we temporarily switch the donor to idle, so we don't accidentally call wakeup_preempt_fair() with idle as the donor. Suggested-by: K Prateek Nayak Signed-off-by: John Stultz --- Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Steven Rostedt Cc: Ben Segall Cc: Valentin Schneider Cc: K Prateek Nayak Cc: kernel-team@android.com --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b8871449d3c69..0ec04008ccd6b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6645,6 +6645,7 @@ static inline void proxy_set_task_cpu(struct task_struct *p, int cpu) static inline struct task_struct *proxy_resched_idle(struct rq *rq) { put_prev_set_next_task(rq, rq->donor, rq->idle); + rq->next_class = &idle_sched_class; rq_set_donor(rq, rq->idle); set_tsk_need_resched(rq->idle); return rq->idle; -- 2.54.0.563.g4f69b47b94-goog