From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F385F395DBF for ; Tue, 24 Feb 2026 13:45:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771940763; cv=none; b=c3JFfP/S3LtbhNgEonmtEqLs0Bt5kwiUTyMP+b+TOBDCiqXA/MKSPwmYqVhN4H/kiuYt5xaTRsUyxvsPVUdgWUUQOUNuaZts+X+i69YV9CTvf7TyRVIfhV0+wJhWgK0iaDtk5LWhixDkxvVQzJE7SlFJPDNIfFUsQIAqkxf8xcM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771940763; c=relaxed/simple; bh=8digOUTup8aUjLpJFlTA3+G1ZQAnCHOF4qhm/REYcH4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fh2ZiyJZwy45YvUWMrNo513ScFQFWAFkWDu8uEow3D0QzXqz1RHIDLdID9JCxCiyAhP0WdeMpNDcBdVrVcHhCLnJ2a1Kg3tu4vBISF7DybnlpVbA4DCYZ84x8rxSPIAp4tshEqDKp8OFS0b/86KVKtkOZr9zCp9c+kMB7l6Sffo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=gE0Qu7fG; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="gE0Qu7fG" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=xVDtrnXYdp0ZTXYRVo53qtbyKJglgzVCjxI+a1PISAg=; b=gE0Qu7fGuW60FarC1Esug73dni ZFjiTyfWJ78NtqqP1TjNjQQfcpu1VO+4G/Ijns43xTakok9gsGzjUg3waO696BLdlYx69+pyV9/7s txk7cEbg3FFT+t4Rzd2wnRoCnp5jQuQ/klAuOeZVkZrTOU+0oWvlqcYzEmAKdqtJkjKFEZ4tT5DWM 9kYTJDLhfgaVEUu827bWMI9LL3uaAUK5XPY6s82tKXbUAatyEUgQYG3KpvQVlXrhPocC5Ul+GIkq/ 5wEctK5FoZ81+diMCHSAaTFaLg3r33pZBmqhzosWdrJ/qMInyxRoA0GvUc+c3YMF/EqCHXHqPcfwb y3PgLvZw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vusja-00000007DqY-2RSy; Tue, 24 Feb 2026 13:45:54 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id CEB26301BD5; Tue, 24 Feb 2026 14:45:52 +0100 (CET) Date: Tue, 24 Feb 2026 14:45:52 +0100 From: Peter Zijlstra To: Juri Lelli Cc: Ingo Molnar , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Philip Auld , Gabriele Monaco , linux-kernel@vger.kernel.org, Bruno Goncalves Subject: Re: [PATCH] sched/deadline: Fix missing ENQUEUE_REPLENISH during PI de-boosting Message-ID: <20260224134552.GA596554@noisy.programming.kicks-ass.net> References: <20260206-upstream-fix-deadline-piboost-b4-v1-1-14043567b89c@redhat.com> <20260207084550.GU1282955@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Feb 09, 2026 at 10:46:18AM +0100, Juri Lelli wrote: > > (afaict nothing clears dl_se::pi_se except rt_mutex_setprio() so that > > should still be valid here -- so we don't need to go find it again) > > But, maybe with something like this? I believe we need to make things > right at this point "promoting" the now becoming lower prio class task > to DEADLINE (inheriting from the task it didn't inherit from in the > past). Maybe we can avoid checking pi_task since dl_prio(newprio). And > also move everything in an helper to remove ifdeffery. > > --- > diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c > index 6f10db3646e7f..856df1a22e3ca 100644 > --- a/kernel/sched/syscalls.c > +++ b/kernel/sched/syscalls.c > @@ -655,6 +655,16 @@ int __sched_setscheduler(struct task_struct *p, > __setscheduler_params(p, attr); > p->sched_class = next_class; > p->prio = newprio; > +#ifdef CONFIG_RT_MUTEXES > + if (dl_prio(newprio) && !dl_policy(policy)) { > + struct task_struct *pi_task = rt_mutex_get_top_task(p); > + > + if (pi_task) { > + p->dl.pi_se = pi_task->dl.pi_se; > + scope->flags |= ENQUEUE_REPLENISH; > + } > + } > +#endif > } > __setscheduler_uclamp(p, attr); I'm still a bit confused on the pi_se thing; if this was a dl task, then rt_mutex_setprio() would've already set this to pi_task->dl.pi_se, no? Anyway, yes something like that, possibly with a helper sounds fine.