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 14C031FF1AE; Wed, 11 Feb 2026 21:44:37 +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=1770846278; cv=none; b=F+z69aXGXEn3AHX109c9Lxe0xn8kK3UWZlxxfGVF03e/Q6lTxDZj4XlHIYQ76tF15fcf+mUAE78tsox8HX7aVmNbh7XiiUCtPNaV1K+iFKDBWAhjOiJNc/u0bs3ojAuMNRoB6FdTIfFAGXhxUSjm3AUKW/zb/CU3aVBOMTjsVsc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770846278; c=relaxed/simple; bh=JMqKerywpg1i4AsO2BcZY243d6hFyXTrcC68qtQaPsc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=P/TsFwiUojvO3rn/c82uFHZkbrN/RK734Els16WI14SUEWrY70FfRe5IdXlBzYVzXiSgwlPw2Nav+JXzDIwCQjzoxIdDqXKeH+LeV45ny9jai2fwJ0QW+noDkWRWdS9Ot2i8DTHFIgN2XoYLdVCT4bn5uk1JlbvKXKvgfme+c0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rqy0CijP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rqy0CijP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB18FC19421; Wed, 11 Feb 2026 21:44:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770846277; bh=JMqKerywpg1i4AsO2BcZY243d6hFyXTrcC68qtQaPsc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rqy0CijPHsw3y/Ope8+judGHByxaXC8M8eCsqUvyAwVaY8G8hcKL8i7lxABnmsgyW rzP6NxnvrtFWXxnfPxrH4/rI1SV0cHbwI8mvyHIwcfGWp8jifwWU/1O6cnO1KaHe4a WdoHCvXj+CK1aN9hiQUiQLgbcBNAPmzjkoT5Kv0rvAyOgyEpwuJQsZUSopsnlrXhWq xTm9XL9IzVeieAgUwO6946WgaXTzcwSvghm1LcQXiOEWsUM9HtsdO5ggko5wzgSWGh BkPIjH+vyRWSI4p9BeEwZyn/IdShqVw4aNO8ROUt71yyfwEInStAMYB5acYN1ixx39 wEBbCcn9FgA4A== Date: Wed, 11 Feb 2026 13:44:36 -0800 From: Jakub Kicinski To: Jacob Keller Cc: Kurt Kanzenbach , Willem de Bruijn , Sebastian Andrzej Siewior , Vadim Fedorenko , Willem de Bruijn , Paolo Abeni , Eric Dumazet , "David S. Miller" , "Loktionov, Aleksandr" , "Nguyen, Anthony L" , "Kitszel, Przemyslaw" , Paul Menzel , "Gomes, Vinicius" , "netdev@vger.kernel.org" , Richard Cochran , "linux-kernel@vger.kernel.org" , Andrew Lunn , "intel-wired-lan@lists.osuosl.org" Subject: Re: [Intel-wired-lan] [PATCH iwl-next v3] igb: Retrieve Tx timestamp directly from interrupt for i210 Message-ID: <20260211134436.1e623034@kernel.org> In-Reply-To: <12520aac-c69a-41a0-9710-497392bc18f6@intel.com> References: <20260205164341.pJvni8kA@linutronix.de> <76acd5cc-eb6f-4c56-a5e6-f6413736afbb@linux.dev> <601f0c4b-52d8-4b60-96bf-f2d65f8073d8@linux.dev> <20260209090621.GiZqTiMJ@linutronix.de> <8e762437-69f9-40d7-bb75-3a45bef1d5d6@linux.dev> <20260209114836.GPU-vnnh@linutronix.de> <78e2af2c-40e6-43f1-9471-42f350e69389@linux.dev> <20260210121207.9kLHroS0@linutronix.de> <87qzqr5vos.fsf@jax.kurt.home> <12520aac-c69a-41a0-9710-497392bc18f6@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 11 Feb 2026 11:29:03 -0800 Jacob Keller wrote: > > Moving the timestamping in IRQ looked like a good solution, because the > > device already signals that the Tx timestamp is available now. No need > > to schedule any worker/work at all. So, it'd be very nice if > > skb_tstamp_tx() could be called from IRQ context. BTW other drivers like > > igc call this function in IRQ context as well. > > Right. Reporting the timestamp from the interrupt is the simplest and > lowest latency method. I know Miroslav had some situations and devices > where it apparently caused more problems than it helped, though I don't > believe anyone else has reproduced those? There's a BH workqueue now, as a replacement for tasklets. Presumably smallest fix would be to switch to that?