From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03728C43334 for ; Fri, 8 Jul 2022 13:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237954AbiGHNrl (ORCPT ); Fri, 8 Jul 2022 09:47:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238268AbiGHNrb (ORCPT ); Fri, 8 Jul 2022 09:47:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DEEA131347; Fri, 8 Jul 2022 06:47:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 83AFF627B0; Fri, 8 Jul 2022 13:47:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 603A0C341C0; Fri, 8 Jul 2022 13:47:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657288045; bh=ti34gkI5DpDj2IoOp134IrjFCpPYMKEKic1GnzTmR8U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WCHFwrgiD/Q53H1kFimo9V1/QQETg/b032nMhy6BWJAbm17bp0cthezUXD1lJkToJ rERjtfYqYWHaex7S1AGRrBO9f2eiMaMAT5uMj+nbngvI+yGvke+DB2k4kzUhBmBz14 Mgkr+X7ruMPEzCQjuH1UxdwGOorfOpN0+uypdjhs= Date: Fri, 8 Jul 2022 15:47:23 +0200 From: Greg Kroah-Hartman To: Sebastian Ene Cc: Rob Herring , Arnd Bergmann , Dragan Cvetic , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, maz@kernel.org, will@kernel.org, vdonnefort@google.com, Guenter Roeck Subject: Re: [PATCH v11 2/2] misc: Add a mechanism to detect stalls on guest vCPUs Message-ID: References: <20220708112344.1965947-1-sebastianene@google.com> <20220708112344.1965947-3-sebastianene@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220708112344.1965947-3-sebastianene@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 08, 2022 at 11:23:45AM +0000, Sebastian Ene wrote: > This driver creates per-cpu hrtimers which are required to do the > periodic 'pet' operation. On a conventional watchdog-core driver, the > userspace is responsible for delivering the 'pet' events by writing to > the particular /dev/watchdogN node. In this case we require a strong > thread affinity to be able to account for lost time on a per vCPU. > > This part of the driver is the 'frontend' which is reponsible for > delivering the periodic 'pet' events, configuring the virtual peripheral > and listening for cpu hotplug events. The other part of the driver is > an emulated MMIO device which is part of the KVM virtual machine > monitor and this part accounts for lost time by looking at the > /proc/{}/task/{}/stat entries. > > Reviewed-by: Will Deacon > Signed-off-by: Sebastian Ene > --- > drivers/misc/Kconfig | 14 ++ > drivers/misc/Makefile | 1 + > drivers/misc/vcpu_stall_detector.c | 223 +++++++++++++++++++++++++++++ > 3 files changed, 238 insertions(+) > create mode 100644 drivers/misc/vcpu_stall_detector.c > > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig > index 41d2bb0ae23a..d5b7610459f7 100644 > --- a/drivers/misc/Kconfig > +++ b/drivers/misc/Kconfig > @@ -483,6 +483,20 @@ config OPEN_DICE > > If unsure, say N. > > +config VCPU_STALL_DETECTOR > + tristate "Guest vCPU stall detector" > + select LOCKUP_DETECTOR This should be a "depends on", not a select, right? This got enabled on my build when I didn't want it to, and trying to track down why it was enabled would be a pain for people. thanks, greg k-h