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 53CEF3D0938; Thu, 28 May 2026 10:53:37 +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=1779965619; cv=none; b=tNe46Am+a/QfOhHEIq6k2+cNeuEG1Rh7cH9Dnh30+Z4VIja0G+MycP4XW+gDrAH3t6GBY1ml3x20c6bxanHvnvFP045aOV0oYdpS2QISaQR6ZzXYErdChhcw4CWLbq9Stjig8LmbKAth2xE/hsgQf6q6FyrpXe5q1iFe3jifHFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779965619; c=relaxed/simple; bh=sWeSNmVN+2nde1J+pCm611g/wKTC4MV5XvLgG0qca5s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cHUhTN6nHOHWctAQTejRpV3ld3A9ol4+Z+MFvJvwLtHKF9mjT9NxOZfUEPi+JXH89shy1/H3yzG/07Q022Asqv8Y2qHZOTatVC8SvkTyvsui+H4QAPMritSQHI6tpNe0THzA/laUpcvX0dp/Uru2ZQbf0D5ieUwwH/nRxgmKO/s= 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=XgDMFSWB; 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="XgDMFSWB" 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=vmJ0MIxHcu6GywVP98RSuXzH8R1cz6RzvzYzBTXLcWQ=; b=XgDMFSWBz53xKzj7s3tmaiRWSn mPrtjimriTrPvI0aWo+sBjxAFnTomEt3sVBc7bhPhi8TaUji6RC3/M/AxkitFgJnujUjKpbpOsXuV JeLszzwWLeJTtc3rBqy3//WSZ5GZpQi2vGKpLaRjERAf1BSxkH0cv9Hh6IIfLX1k6ecieoVESsrLu 3rHb47LamIi2dG8Jz8aPVjJANgIrZlV810yb0CCjJwUmknuK9JiahNzNf384/aO4/o5b7RU6raFPo Nc4Nxu5gCpANnSiqIpxHIB2X4HC5U8XqNGcy/PsnJLgQDcW1vphnTMIvfk0MBZ+XNavEAxckssrQ5 l0N2225g==; Received: from 2001-1c00-8d85-4b00-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:4b00:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSYMf-0000000GDSi-2KFs; Thu, 28 May 2026 10:53:32 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 556DB300673; Thu, 28 May 2026 12:53:25 +0200 (CEST) Date: Thu, 28 May 2026 12:53:25 +0200 From: Peter Zijlstra To: Boqun Feng Cc: Catalin Marinas , Will Deacon , Jonas Bonn , Stefan Kristiansson , Stafford Horne , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Waiman Long , Andrew Morton , Andrii Nakryiko , Eduard Zingerman , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa , Shuah Khan , Miguel Ojeda , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Jinjie Ruan , Lyude Paul , Thomas Huth , Sohil Mehta , "Xin Li (Intel)" , Pawan Gupta , Nikunj A Dadhania , Joel Fernandes , Andy Shevchenko , Randy Dunlap , Yury Norov , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-s390@vger.kernel.org, linux-arch@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, rust-for-linux@vger.kernel.org, Onur =?iso-8859-1?Q?=D6zkan?= , Daniel Almeida Subject: Re: [PATCH v2 12/12] s390/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS Message-ID: <20260528105325.GI343181@noisy.programming.kicks-ass.net> References: <20260526152148.30514-1-boqun@kernel.org> <20260526152148.30514-13-boqun@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@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: <20260526152148.30514-13-boqun@kernel.org> On Tue, May 26, 2026 at 08:21:48AM -0700, Boqun Feng wrote: > From: Heiko Carstens > > Convert s390's preempt_count to 64 bit, and change the preempt > primitives accordingly. > > Signed-off-by: Heiko Carstens > Signed-off-by: Boqun Feng > Link: https://patch.msgid.link/20260509181249.16281C67-hca@linux.ibm.com > --- > arch/s390/Kconfig | 1 + > arch/s390/include/asm/lowcore.h | 13 +++++++---- > arch/s390/include/asm/preempt.h | 41 +++++++++++++++------------------ > 3 files changed, 29 insertions(+), 26 deletions(-) > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index ecbcbb781e40..cbbca82f8443 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -276,6 +276,7 @@ config S390 > select PCI_MSI if PCI > select PCI_MSI_ARCH_FALLBACKS if PCI_MSI > select PCI_QUIRKS if PCI > + select HAS_SEPARATE_PREEMPT_RESCHED_BITS > select SPARSE_IRQ > select SWIOTLB > select SYSCTL_EXCEPTION_TRACE > diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h > index 50ffe75adeb4..0974ab278169 100644 > --- a/arch/s390/include/asm/lowcore.h > +++ b/arch/s390/include/asm/lowcore.h > @@ -160,10 +160,15 @@ struct lowcore { > /* SMP info area */ > __u32 cpu_nr; /* 0x03a0 */ > __u32 softirq_pending; /* 0x03a4 */ > - __s32 preempt_count; /* 0x03a8 */ > - __u32 spinlock_lockval; /* 0x03ac */ > - __u32 spinlock_index; /* 0x03b0 */ > - __u8 pad_0x03b4[0x03b8-0x03b4]; /* 0x03b4 */ > + union { > + struct { > + __u32 need_resched; /* 0x03a8 */ > + __u32 count; /* 0x03ac */ > + } preempt; > + __u64 preempt_count; /* 0x03a8 */ > + }; I'm a little confused by this union; afaict it isn't actually used.