From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 697162BEFE2 for ; Wed, 16 Jul 2025 08:59:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752656392; cv=none; b=cKaZYSu/3VsZSR33OVLnKdnGOxig6yn3X9JoF8l5cNaF/r8+DXYKgeZmwC/CAxFLFbELdLqtzD37ixZU0lz1jswmKnojCkwiriJHqsXdw2C06O1e+2k3AePQr666YG61D2Qm80SaKTqWHVDBwxpvfcKQ41C+UwZjqjJx8Ut7SEc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752656392; c=relaxed/simple; bh=rYiazEuw3scjsu8vgivyrSqTbYtX4ZfFIDqZ6D7u1m8=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=G2j66WlDS6THehmmJPtwgfRsZUjiX8e/92QUgZK6u9CYJhefD9gesI2+Wb5bsvWtx1BYd5ukvfLbjAXyBd9ocO5tRzNK41qZVsZKlW+0X1FvXZHX4Xm66Ee8OyIhcXSwjGg0EdFoUWtZdJxlHIrbQMIBvB/MXllbYEKPhkTIqgU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=KNIbr+GN; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KNIbr+GN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752656390; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=rYiazEuw3scjsu8vgivyrSqTbYtX4ZfFIDqZ6D7u1m8=; b=KNIbr+GNaaOWfNToA6UArZBpkqayNpewOefffu/jkHUszEJFOMn49KlnncLffaYmTYfibm OokT+NukEr/0Do08TyXMtOJp2rKx/LmFttVyKOUvwHCsWwAitZB7vUGjZ88AOMR8O8U6eY FwU98VfynXqDDtFb2b5iFlcuFxpToBc= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-651-VCXKO99oO0e-iX3RDuFt7Q-1; Wed, 16 Jul 2025 04:59:48 -0400 X-MC-Unique: VCXKO99oO0e-iX3RDuFt7Q-1 X-Mimecast-MFC-AGG-ID: VCXKO99oO0e-iX3RDuFt7Q_1752656387 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-454dee17a91so49546855e9.3 for ; Wed, 16 Jul 2025 01:59:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752656387; x=1753261187; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=rYiazEuw3scjsu8vgivyrSqTbYtX4ZfFIDqZ6D7u1m8=; b=s/XdVbMEIuGh/yilt4ifzxCzE4KnxxSCLKE3eZNyGAE89o9aYsChBBrfh0lcLPLmui nSuc36z40laMQw4wvcGtjPft70309sdZ7vW6dX/WOfAYYs9k1viuFFpJV8650tc49nua X9edcpztlDH7C6p4IMXPT3q78f+liNUAwisbj2Ljo1tzqif64hB9qUJWUmvLIHvY4Ro8 gYdd9fHVUZGvNB+ZPdFdDKWQe3IevQRvDuTjEeAdjhvlBZeOBAqgAJ/6CjspS7bDfuIg wDTc/KWyIhhOQk3wd5i09iRuMesZ1SBZCMFwhf4hj2i/o5Wr3s9K5gOg8RW+fT12Eqct p67g== X-Gm-Message-State: AOJu0YyvOUyVJVkp0AWUYz7yesUsyT6f4ZJkJfpyMh7zzLMRz8vS5aPa Jg+D+TevjBrk45723jMQcbxDjBAd1/4elshqyIuFdxRrmS+AFV7JXD0lgHmnJF3+8XcifIlb+Ym IuW5LmFRpqv+Kic4NJewtxhLH+COi4yiQAkd1N6c3TcGK7dSg0+BVgJkWq/h59LlQWg== X-Gm-Gg: ASbGncu78v4lRH0/YZIzi7iQP3q7q4EHrx4p8E1hsqwQDfxxQZhaWB/9Rea87yLqYFO ctiDQaKFyFnD3kEQ2ISBlV9/zh7+28sDIXg0oZiurxXWg0NDVrrXTT+12BwQu5OEFlh/66ew0RR /v+0qwz9ay5s8/owBs/eYj98GFACHmdFYPwGQi+xPBsKsZbG1YgM2W9S9RF7Fvcw1PQV1aNbrSQ jBTfmGpMIohN426UNKGP1e1l9lCUm/NSrOctvqzTajuUCFT5CviVyfhKfpJgeq0Q4bzmrg18uWl tmR5b7/h14fBoAC1IBCNeYENO8aAklmiRteDI9Bs/OOjP/JHUld7ZI+W5lvTEqspfA== X-Received: by 2002:a05:600c:5486:b0:453:2066:4a26 with SMTP id 5b1f17b1804b1-4562e39b9a1mr20121785e9.16.1752656387495; Wed, 16 Jul 2025 01:59:47 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGvh4XGqgjiXRNpbWt+0e4yPX9fyRdtuorAJBNJIz/t3WeV48Yv6FM74WTtdQhrUxK0tGt86A== X-Received: by 2002:a05:600c:5486:b0:453:2066:4a26 with SMTP id 5b1f17b1804b1-4562e39b9a1mr20121435e9.16.1752656387029; Wed, 16 Jul 2025 01:59:47 -0700 (PDT) Received: from gmonaco-thinkpadt14gen3.rmtit.csb ([185.107.56.40]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3b5e8e0dbddsm17513367f8f.63.2025.07.16.01.59.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Jul 2025 01:59:46 -0700 (PDT) Message-ID: <37bc7ab78b03f4e794a5466d9cc0a1e187e1ae72.camel@redhat.com> Subject: Re: [PATCH v3 11/17] rv: Retry when da monitor detects race conditions From: Gabriele Monaco To: Nam Cao Cc: linux-kernel@vger.kernel.org, Steven Rostedt , linux-trace-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Tomas Glozar , Juri Lelli , Clark Williams , John Kacur Date: Wed, 16 Jul 2025 10:59:44 +0200 In-Reply-To: <20250716084520._QLbd5AY@linutronix.de> References: <20250715071434.22508-1-gmonaco@redhat.com> <20250715071434.22508-12-gmonaco@redhat.com> <20250715152322.Os4lDq_B@linutronix.de> <20250716082712.L9z_ptHK@linutronix.de> <20250716084520._QLbd5AY@linutronix.de> Autocrypt: addr=gmonaco@redhat.com; prefer-encrypt=mutual; keydata=mDMEZuK5YxYJKwYBBAHaRw8BAQdAmJ3dM9Sz6/Hodu33Qrf8QH2bNeNbOikqYtxWFLVm0 1a0JEdhYnJpZWxlIE1vbmFjbyA8Z21vbmFjb0ByZWRoYXQuY29tPoiZBBMWCgBBFiEEysoR+AuB3R Zwp6j270psSVh4TfIFAmbiuWMCGwMFCQWjmoAFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgk Q70psSVh4TfJzZgD/TXjnqCyqaZH/Y2w+YVbvm93WX2eqBqiVZ6VEjTuGNs8A/iPrKbzdWC7AicnK xyhmqeUWOzFx5P43S1E1dhsrLWgP Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2025-07-16 at 10:45 +0200, Nam Cao wrote: > On Wed, Jul 16, 2025 at 10:38:11AM +0200, Gabriele Monaco wrote: > > Yes you can, but I wouldn't do so silently. >=20 > Why not? The absolute worst that we get, is the rare case where a bug > appears at the exact same time. In that case, we would get a false > negative. >=20 > And I think that is really really rare. Well, we wouldn't even know how rare it is because we don't track it! It may be a harmless note but might also be a design flaw in the monitor, so it should be possible to understand when it happens. > Yes, if you really want to emit some sort of warning here, it should > be > absolutely clear that the monitor itself is having a hiccup, not the > monitored kernel. Yeah totally, not saying that other errors reported in the wild are going to be necessarily the kernel's fault though ;) But let's keep these cases separate going forward nonetheless. Thanks, Gabriele