From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (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 CA0431D5CFB for ; Sun, 18 Jan 2026 17:02:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768755777; cv=none; b=h0SmQN7HrMeJINzJ7W40zH6dwsoSL1b6veZUO6NjwAp7ikKRykIsS3rQ/DdMHpq5wONLtin4Hl2FLLcrlymecLZdRdKXyGHZ8Bw+eExDpk/XDZNpYIdpgu5KY6mKCWTOD1rx2e+FLZqNHILc840+HY9B0k9PGU9g+uvKrNOzzgs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768755777; c=relaxed/simple; bh=++Np939W0w+9LTtwQN5ddj4LNlIg4JvuTfXCCRly/kE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pEaYo51DINUwJBb9zBNOmBDi0NE/vjBRu7z7ARRQ9cb0RnPqvf4dS85RA0wFZrUY3N4Gy/hy7ElEWIsJDCqmcHH6fLcPEvUhWC+ahlmecQBdHruOPdarnWP5CIGroIW4QqKmMG3Sgna/nlB2Fj953gxdGBdnL8d0cN0Xi0pnTbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=AqtYKp4K; arc=none smtp.client-ip=91.218.175.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="AqtYKp4K" Message-ID: <2f5f4a18-82b4-4f67-ae98-cdf5b7f8012b@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1768755773; 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; bh=IHMiTnX6Q49LBdFrwHo07sttVUw6bSThK4YGNL15ubo=; b=AqtYKp4Kai+NPIKDqHmhHcf104LiGy3h4QMvSTQB+3aOI/E3tDOOnCCDsspehpbgy5AwSz OsWKsTWTZQ16BO/AkAleStAw0AM8yiVQyPuEqR9DlD+0USj4+h9nUAmjmszxiiLoJ+uXDn FyuskXH5ZpH2q7F3MetUsrjU8Kksflc= Date: Mon, 19 Jan 2026 01:02:47 +0800 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 6.6 0/3] net: Backlog NAPI threading for PREEMPT_RT To: Greg Kroah-Hartman Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org References: Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Wen Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Sorry, we accidentally wrote 'PATCH 6.1' as' PATCH 6.6 ', please ignore this series. We will resend the correct one, thanks. -- Best wishes, Wen On 1/19/26 00:15, wen.yang@linux.dev wrote: > From: Wen Yang > > Backport three upstream commits to fix a warning on PREEMPT_RT kernels > where raising SOFTIRQ from smp_call_functio triggers WARN_ON_ONCE() > in do_softirq_post_smp_call_flush(). > > The issue occurs when RPS sends IPIs for backlog NAPI, causing softirqs > from irq context on PREEMPT_RT. The solution implements backlog > NAPI threads to avoid IPI-triggered softirqs, which is required for > PREEMPT_RT kernels. > > commit 8fcb76b934da ("net: napi_schedule_rps() cleanup") and > commit 56364c910691 ("net: Remove conditional threaded-NAPI wakeup based on task state.") > are prerequisites. > > The remaining dependencies have not been backported, as they modify > structure definitions in header files and represent optimizations > rather than bug fixes, including: > c59647c0dc67 net: add softnet_data.in_net_rx_action > a1aaee7f8f79 net: make napi_threaded_poll() aware of sd->defer_list > 87eff2ec57b6 net: optimize napi_threaded_poll() vs RPS/RFS > 2b0cfa6e4956 net: add generic percpu page_pool allocator > ... > > Eric Dumazet (1): > net: napi_schedule_rps() cleanup > > Sebastian Andrzej Siewior (2): > net: Remove conditional threaded-NAPI wakeup based on task state. > net: Allow to use SMP threads for backlog NAPI. > > net/core/dev.c | 162 +++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 118 insertions(+), 44 deletions(-) >