From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 019881FFC73 for ; Fri, 21 Feb 2025 16:47:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740156465; cv=none; b=ohlVDved9dcjyhXNSECc4u4ufEs2Ym9+2too44twIQtAPYvY73/6tX6bZW3sKdFfwEbPrqDl4b49dkT9+VQ39/WYkVatW+P+s7CA8dK42DM6RKzVAfPP4smcdC0m12z+sSYnaNwIBFUz+ZKAeqAqBqqg0zKGICgxPDyIz9wNzkY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740156465; c=relaxed/simple; bh=QGsnl3UDxL6o+Zb5sIuMg4mK/ph+5EQXHCi9skL7zbg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=l4g9ly1KzOfnJ/GX68+FoWJydA3meuvCmIPy9N6C9WNyl4r5PPTNLTzwVtNi4x8JvpSmSu+oegHKXPsrFLA0BdLY9orjh8tUCHyReI6oddsw/qMWmISsteEDpR8NjpqpFkfuttxs523t7pNRqfeUALLJSfLkgtfwl9pUNeIELks= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9253C4CEE2; Fri, 21 Feb 2025 16:47:43 +0000 (UTC) Date: Fri, 21 Feb 2025 11:48:12 -0500 From: Steven Rostedt To: Sebastian Andrzej Siewior Cc: Wander Lairson Costa , linux-trace-kernel@vger.kernel.org, Masami Hiramatsu , Mathieu Desnoyers , Thomas Gleixner Subject: Re: [PATCH] ftrace: Correct preemption accounting for function tracing. Message-ID: <20250221114812.6030671d@gandalf.local.home> In-Reply-To: <20250221162146.9KWeIdA0@linutronix.de> References: <20250220140749.pfw8qoNZ@linutronix.de> <44ymxgot422oetab62w55rth5tqrzseyhwirxg2ho7vzvvkaud@qiada52ckt25> <20250220115400.4d75d881@gandalf.local.home> <20250221162146.9KWeIdA0@linutronix.de> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Fri, 21 Feb 2025 17:21:46 +0100 Sebastian Andrzej Siewior wrote: > On 2025-02-20 11:54:00 [-0500], Steven Rostedt wrote: > > > kworker/0:5-88 [000] D.Zf2 211.983391: igbvf_reset_L14: (= igbvf_reset+0x62/0x120 [igbvf]) > > > kworker/0:5-88 [000] .N... 211.983396: igbvf_reset_L16: (= igbvf_reset+0x7b/0x120 [igbvf]) =20 > =E2=80=A6 > > > (Except in line 6 where it show 'f', which seems to be an unrelated i= ssue) =20 > >=20 > > But it appears to be consistent. > >=20 > > Let me go and add some probes and see what they show. The output you ga= ve > > me that I requested didn't show anything unusual. =20 >=20 > Since I just noticed that you posted the patches, did you find anything? > From looking at it, if we preemption at 0, migrate disable at 3 then a > substraction of one would underflow the preemption counter to f and > migrate disable to 2. But based on code inspection mg should be at 1. > And this does not explain where D & Z is coming from. I haven't found the bug for this yet, but I need to send out other fixes. The preempt count issue you posted is agnostic to this issue, so I just took it and added it to my current queue for this rc release. -- Steve