From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Mon, 29 Jun 2015 12:23:35 +0100 Subject: [PATCH] ARM64: smp: Silence suspicious RCU usage with ipi tracepoints In-Reply-To: <20150629100251.GZ7557@n2100.arm.linux.org.uk> References: <1435176858-9568-1-git-send-email-sboyd@codeaurora.org> <20150629100251.GZ7557@n2100.arm.linux.org.uk> Message-ID: <20150629112335.GE29907@e104818-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jun 29, 2015 at 11:02:51AM +0100, Russell King - ARM Linux wrote: > 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" [...] > The Fixes: line has a standard format, which is not the formatting above. > Please see Documentation/SubmittingPatches section 2. Thanks. I re-wrote it in this instance. What's not clear to me is whether cc: stable is still necessary with a Fixes: tag (I add it just in case). Anyway, to simplify the process, I came up with a .gitconfig alias: [alias] show-fixes = !git show --pretty=format:\"Fixes: %h (\\\"%s\\\")\nCc: "#" $(git describe --match="v*" --contains $1 | cut -d - -f -1)+\n\n%b\" $1 "#" And another for .vimrc (to replace a Fixes: line): command! GitFixes \ :.!read tagname commit; git show-fixes $commit 2> /dev/null | head -n 2 -- Catalin