Re: [PATCH v5 15/18] watchdog/perf: Add a weak function for an arch to detect if perf can use NMIs
From: Mark Rutland <mark.rutland@arm.com>
Date: 2023-06-12 14:00:24
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linux-arm-kernel, linux-perf-users, lkml, sparclinux
On Mon, Jun 12, 2023 at 06:55:37AM -0700, Doug Anderson wrote:
Mark, On Mon, Jun 12, 2023 at 3:33 AM Mark Rutland [off-list ref] wrote:quoted
On Fri, May 19, 2023 at 10:18:39AM -0700, Douglas Anderson wrote:quoted
On arm64, NMI support needs to be detected at runtime. Add a weak function to the perf hardlockup detector so that an architecture can implement it to detect whether NMIs are available. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- While I won't object to this patch landing, I consider it part of the arm64 perf hardlockup effort. I would be OK with the earlier patches in the series landing and then not landing ${SUBJECT} patch nor anything else later.FWIW, everything prior to this looks fine to me, so I reckon it'd be worth splitting the series here and getting the buddy lockup detector in first, to avoid a log-jam on all the subsequent NMI bits.I think the whole series has already landed in Andrew's tree, including the arm64 "perf" lockup detector bits. I saw all the notifications from Andrew go through over the weekend that they were moved from an "unstable" branch to a "stable" one and I see them at: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/log/?h=mm-nonmm-stable When I first saw Anderw land the arm64 perf lockup detector bits in his unstable branch several weeks ago, I sent a private message to the arm64 maintainers (yourself included) to make sure you were aware of it and that it hadn't been caught in mail filters. I got the impression that everything was OK. Is that not the case?
Sorry; I'm slowly catching up with a backlog of email, and I'm just behind. Feel free to ignore this; sorry for the noise! If we spot anything going wrong in testing we can look at fixing those up. Thanks, Mark.