Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753146AbbF2KDS (ORCPT ); Mon, 29 Jun 2015 06:03:18 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:35550 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752145AbbF2KDM (ORCPT ); Mon, 29 Jun 2015 06:03:12 -0400 Date: Mon, 29 Jun 2015 11:02:51 +0100 From: Russell King - ARM Linux To: Stephen Boyd Cc: Catalin Marinas , Will Deacon , Nicolas Pitre , linux-kernel@vger.kernel.org, Steven Rostedt , John Stultz , "Paul E. McKenney" , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM64: smp: Silence suspicious RCU usage with ipi tracepoints Message-ID: <20150629100251.GZ7557@n2100.arm.linux.org.uk> References: <1435176858-9568-1-git-send-email-sboyd@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435176858-9568-1-git-send-email-sboyd@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1928 Lines: 41 On Wed, Jun 24, 2015 at 01:14:18PM -0700, Stephen Boyd wrote: > John Stultz reported an RCU splat on ARM with ipi trace events > enabled. It looks like the same problem exists on ARM64. > > At this point in the IPI handling path we haven't called > irq_enter() yet, so RCU doesn't know that we're about to exit > idle and properly warns that we're using RCU from an idle CPU. > Use trace_ipi_entry_rcuidle() instead of trace_ipi_entry() so > that RCU is informed about our exit from idle. > > Cc: John Stultz > Cc: Steven Rostedt > Cc: Paul E. McKenney > Cc: Nicolas Pitre > Fixes: 45ed695ac10a "ARM64: add IPI tracepoints" > Signed-off-by: Stephen Boyd I can find no trace of your equivalent ARM patch in my mailbox, but my comment is as relevant to that message as it is to this one. The Fixes: line has a standard format, which is not the formatting above. Please see Documentation/SubmittingPatches section 2. Thanks. I've fixed it when applying the ARM version of this patch. However, I'm left wondering whether the lack of update to change the "Silence" to "Fix" which I _stumbled_ over later in this thread is laziness on your part - had it not been for the malformed Fixes: line, I would not have known to update that. We all gets lots of email every day, expecting people to remember some comment in the dim and distant past made to a similar but different patch is not really on. Please ensure that you update your patches in future. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/