From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2806C3B0AC6; Tue, 21 Jul 2026 20:46:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666801; cv=none; b=OONLwgU/BVPtAxfHjR6Asjdu0UudgzFS85Bpk4Hec6wHM/MOD7G6wCGSVWeJ+usoCr3PvAWqFX43Ym1cuXeoFrbgWKGWuHhV2adz8hnV4JFfIAE2VkLO3DQOE256zog3NCCo/A+N+wfcGfJkTkw3NoKLUz7fSQjp86TNaVA1l2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666801; c=relaxed/simple; bh=jfIdykMe1g21nIRJ9jRtP2BYbCdMPGkuYNJNyyjWhV0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N6bpUDAKvVJ6FptJGaFCCcybrlXZys5wweurS2DOWqyrj2sRcMr+jyqswdGw2Cp19vRD0LyBI/eA8W2LmkwuOrQVHjbil4xcFsqLXGOMjplh4ZvklSXjlgrKHqGU0KYAsgCo9jy/CbRxsa/itwlfPT0RH+MfZvDn6dbl9yIna8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=I653e2AV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="I653e2AV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CEC01F000E9; Tue, 21 Jul 2026 20:46:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666800; bh=bK8ZhIdV7p6lEoESlZoiGgsvCkiiDSuN9bqQzgZRXRY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=I653e2AVCwwWaKfRNRGy1WFXvfSX5EZlH7gGGN/2Vlqwy08iuE6p3ypIXtSeOSFaL V7Atc9rpN/60Z5BGqzK8x2jFkTv2POFjHRTE6vGgzHISdemy6WfWZ0LYR45fIauAUj GSMciNKLMnvkDwlKw73laAzUs6SSOr2KoDQUbBGk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Michael S. Tsirkin" , Longjun Tang , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 0819/1266] virtio_net: disable cb when NAPI is busy-polled Date: Tue, 21 Jul 2026 17:20:56 +0200 Message-ID: <20260721152500.187305363@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Longjun Tang [ Upstream commit 1eb8fc67ca41db71c90866ff76c990d85247daef ] When busy-poll is active, napi_schedule_prep() returns false in virtqueue_napi_schedule(), so virtqueue_disable_cb() is skipped. The device may keep firing irqs until reaches virtqueue_napi_complete(). Under load (received == budget), it will lead to a large number of spurious interrupts. Fix it by disabling the callback at the virtnet_poll() entry. This keeps the callback off while we poll and it is re-enabled by virtqueue_napi_complete() when going idle. Fixes: ceef438d613f ("virtio_net: remove custom busy_poll") Acked-by: Michael S. Tsirkin Signed-off-by: Longjun Tang Link: https://patch.msgid.link/20260629024230.37325-1-lange_tang@163.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/virtio_net.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8be173b76abe5b..fe0e647808cd7e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2228,6 +2228,9 @@ static int virtnet_poll(struct napi_struct *napi, int budget) unsigned int received; unsigned int xdp_xmit = 0; + if (budget) + virtqueue_disable_cb(rq->vq); + virtnet_poll_cleantx(rq, budget); received = virtnet_receive(rq, budget, &xdp_xmit); -- 2.53.0