From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 A7FBB29405 for ; Thu, 23 Oct 2025 19:23:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761247438; cv=none; b=rwMcu7PJ0FaMw99783ESdBY/aFaTlRiPZctU/BHwjsWP+53u4LRh/QydBTKDQhv7DLpILDlXjnUK6ICZ7LBWFaFSgiWDHCqabOT/j5yGNv/ipdDDjuzVikHuN6QN/Zr0WXtdodwmepcD7DvX/loEoVCYrsf1VGpUJ1IACV1V/nw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761247438; c=relaxed/simple; bh=dyJm5kfT+wwoAXrFOv1gzXzfXi6fTeq4CMgppAJ+OhU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ax8PvHKLGF/wzoTs7vR+CT43FExI/5RezarH+rMLBlqro8oP/GB0WolyFRnCCHSuxHOuWE/v5ueXTRGK+5lEggzN4nzt08pvtE3bCqQ39AURQ1tmsnV6Vm6E0TAaIWEtJEhcGoV1FSOS3JBt+5Oxsbgkjj8Npj7Lv1PjcL7fCtk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=BeQGsgjY; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=m/gBCSeI; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="BeQGsgjY"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="m/gBCSeI" Date: Thu, 23 Oct 2025 21:23:53 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1761247434; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7ogCKyf+ZhAJJt4mNbS3YCVOVR0Q9eZHL6eEX+BzXhU=; b=BeQGsgjYWkHrqj61jTAtbdLkEkbM+BrPGF0fak3f6Nl7kwgutaNbZdZI0jEZQlrtL2kmWV WZ9h/S6kvquom8JHnBsL+fBYXy70DtqieGcJB32RiLgvlSS1WZWJ0r0LeZtgPEEd/y/UKu iD5m+qsy/c+3biYKXrIJRD1PaQ+rDadhWDWqS8ixGERuFkmVLywROrgHCJTjLT3oJLNCnw U6EH9MnFBqyWpdT/PNDtyXJRSboAlYTPevXZaDk+uIoI/v7FMbczxzRzESXGgrG3h9lfSU xnFrd1x+CBMCipSd07+98oDVApltPbObyM+8ceG/fSbvTFy6hgmUAyc4acRNkw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1761247434; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7ogCKyf+ZhAJJt4mNbS3YCVOVR0Q9eZHL6eEX+BzXhU=; b=m/gBCSeIxN6gk9DMIZ21dwkb3pz8ZXcoe2RRMqk6rf5DA8e+oC3uTtxz9QX4L3O5MYIiMo MXTGyLm05jG1pCDg== From: Sebastian Andrzej Siewior To: Oleg Nesterov Cc: "Luis Claudio R. Goncalves" , Peter Zijlstra , Clark Williams , Steven Rostedt , Tejun Heo , David Vernet , Barret Rhoden , Josh Don , Crystal Wood , linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Juri Lelli , Ben Segall , Dietmar Eggemann , Ingo Molnar , Mel Gorman , Valentin Schneider , Vincent Guittot , Thomas Gleixner , Wander Lairson Costa Subject: Re: usage of DEFINE_WAIT_OVERRIDE_MAP(LD_WAIT_SLEEP) Message-ID: <20251023192353.Wkng87fi@linutronix.de> References: <20250729114702.GA18541@redhat.com> <20250729130936.GB18541@redhat.com> <20250801102428.GB27835@redhat.com> <20250811105948.OafBprND@linutronix.de> <20251020145310.GA9608@redhat.com> <20251023135316.1ZRx0UU5@linutronix.de> <20251023152942.GC26461@redhat.com> <20251023153750.C6EU9NL6@linutronix.de> <20251023155339.GE26461@redhat.com> 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=utf-8 Content-Disposition: inline In-Reply-To: <20251023155339.GE26461@redhat.com> On 2025-10-23 17:53:40 [+0200], Oleg Nesterov wrote: > Sebastian, Hi Oleg, > sorry. I guess this is my fault, but I can't understand your reply... > Could you spell please? So you refer to this: | /* PREEMPT_RT kernels map spinlock to rt_mutex */ | #include | | typedef struct spinlock { | struct rt_mutex_base lock; | #ifdef CONFIG_DEBUG_LOCK_ALLOC | struct lockdep_map dep_map; | #endif | } spinlock_t; spinlock_t on PREEMPT_RT does not use (struct) rt_mutex as the comment claims. It uses just the basic building block which is "struct rt_mutex_base". This requires linux/rtmutex.h. spinlock_t on PREEMPT_RT uses LD_WAIT_CONFIG via SPIN_DEP_MAP_INIT as !PREEMPT_RT. Nothing changes here. struct rt_mutex on the other hand uses LD_WAIT_SLEEP and this one is like struct mutex but with PI. Sebastian