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 D73D9204F9C for ; Mon, 9 Jun 2025 09:50:19 +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=1749462621; cv=none; b=LcMV88P7iQM4dW4TUChFr7aGd8nzgwfPNGDYvHeXgIC/duES4Cx6P0Sx4QLRjKXDbPKjyh2I55ut+NVFg+mInESJh6GEA3GmwQK08y9BV6AeAIG7Xbls9yLBSCd3L4vBORgMVQ2XOfFm2QadygE44fJgjBB7vZiW7zqISYe1OJY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749462621; c=relaxed/simple; bh=FWGBvYAMVcHEvCmJwnyaFb3mVy8uSeOvKuPGtiaYSWk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=qWtDbYLB8rUwpVflrFzKO3Bq5jzARTdsnhw4FRYvIqOEz7YxlbO5PEj5S2aiQ+BbEzBIzf+NMW7LvwlW0XAe63svUreerSJF9vZUF+rkGgsIK/tyfc3e7NsOpdRBnCkOuiDMowEt2EYZmT2ra3a7QU7aroqUX7jgW8N24wKaJFc= 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=fb5QSuC3; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=TMmLSqt/; 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="fb5QSuC3"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="TMmLSqt/" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1749462617; 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=mbz04pOM3NYmx/zT2wl8ZoqNB/eXgeWPDviW1H791pM=; b=fb5QSuC3krZuYmrsc9ISCrgUEYqmdJqTR3jLEuwH/gKWpzffVZ5PEg9GDLWBZEjtQDiPiv U3OsHe8h0sDlDE60V8ZikpAs5RE40RFT2F2x3zp8aSi5jK+Ki7LxW8PyPRkloPM0ztqHQ1 +xJNe93K7cfa+sAk3KpXEX8093ET4SXGGYnhiEfQZ7IxV37XXzIdUPn96IyXLbkx+5ir9K fMZnHjjNRLeOe8Rq3BtmEK7nhT0qJgDQBfIIWX0XpQNHU0/uVDqKLN2HZwwUD+NZuJtKfh 9C4x08WCnEW1RKcZZzlOMVEr+WmSWs6nTlEMW3lumwJSOwS0kHAT29XA/jmiMA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1749462617; 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=mbz04pOM3NYmx/zT2wl8ZoqNB/eXgeWPDviW1H791pM=; b=TMmLSqt/78pSMqdwBAy2SNly0YOaD7tYq38EIXaW0gV2h2OsZS2jalFbPGL47BGStjO1Wp K23lXmvTZj5ilIAw== To: Zenghui Yu Cc: LKML , Jiri Slaby , Peter Zijlstra Subject: Re: [patch V2 06/45] genirq/proc: Switch to lock guards In-Reply-To: <873b0e9a-0e71-0eaf-b057-8a118d9ccabf@huawei.com> References: <20250429065337.117370076@linutronix.de> <20250429065420.373998838@linutronix.de> <873b0e9a-0e71-0eaf-b057-8a118d9ccabf@huawei.com> Date: Mon, 09 Jun 2025 11:50:16 +0200 Message-ID: <878qm1p7l3.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Sun, Jun 08 2025 at 20:45, Zenghui Yu wrote: > On 2025/4/29 14:54, Thomas Gleixner wrote: >> - raw_spin_lock_irqsave(&desc->lock, flags); >> - if (desc->affinity_hint) >> - cpumask_copy(mask, desc->affinity_hint); >> - raw_spin_unlock_irqrestore(&desc->lock, flags); >> + scoped_guard(raw_spinlock_irq, &desc->lock) { > > Any reason it has been switched to a raw_spinlock_irq? Yes. This code is always thread context and can never be invoked with interrupts disabled. So there is zero reason to use irqsave(). > I've hit some random Oops with the backtrace looks like: > > Call trace: > string+0x110/0x3b8 (P) > vsnprintf+0x2f0/0xac8 > seq_printf+0x180/0x220 > show_interrupts+0x4e0/0x7e0 > seq_read_iter+0x350/0xd80 > proc_reg_read_iter+0x194/0x248 > vfs_read+0x5b0/0x940 > ksys_read+0xf0/0x1e8 > __arm64_sys_read+0x74/0xb0 > invoke_syscall+0x74/0x270 > el0_svc_common.constprop.0+0xb4/0x240 > do_el0_svc+0x48/0x68 > el0_svc+0x4c/0xe8 > el0t_64_sync_handler+0xc8/0xd0 > el0t_64_sync+0x1ac/0x1b0 > > I haven't dig further. But it looks to me that this patch had introduced > functional change and I'm planning to give the following diff a go on > the same box. That won't help at all because the actual crash is within show_interrupts().... Thanks, tglx