From nobody Thu Dec 18 08:53:35 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD1D7C77B75 for ; Thu, 4 May 2023 02:27:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229712AbjEDC1w (ORCPT ); Wed, 3 May 2023 22:27:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229470AbjEDC1u (ORCPT ); Wed, 3 May 2023 22:27:50 -0400 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D57DB1B0 for ; Wed, 3 May 2023 19:27:48 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id d2e1a72fcca58-64374860853so24228b3a.1 for ; Wed, 03 May 2023 19:27:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1683167268; x=1685759268; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=u+BgJuHtqJ6xHJQzKeFgk31WipZJ6dbt5GNbeuwFI6E=; b=SlMNXjdGsbfr6N9kkbZZeyQ43lxVvkoMsCd0YWIFya3W1IZe5rU7VOgbO3UVhc43eH g06ZGzXgN0/NNLgGmKCYkuKabXwfcBLb6i7HCPR7VLv9wm/uuuEi8bVqUBEhieYeRciB eaF7AVNvwHQCmhNhS72C+iUrCgVz3YOvhh3ZUTufEkG8kpdc6uu7+q7utraGNVEMZ6UO baw0GRKFuihvmQ51q1SoimeqotVxGOtqNlIKg/L2j0Q5AkI/wflyQ5Zo39dwKYwYDmD8 j/l8qg936kNf89L9H4QGXmxUJZoRGpMuyQCLF1T+LbFmIxd38cdREerkfVUJr3uU8OYI yHfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683167268; x=1685759268; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=u+BgJuHtqJ6xHJQzKeFgk31WipZJ6dbt5GNbeuwFI6E=; b=GZO01k6SMssPptlpTWSOmea0RXW9yJmiNNs/zdIbehGU0PY3aGNRa1i0EASQYYMfql jV7SMrTwaTsjDYP3CTAXtpcbE2P+nrAW+T8WTliPLkls4iBhJfuMomnphZkv2JxxgYzQ 5mVBhKuxTlAfvpXhNyLHybLB0kMdjEUC6+SMS2HwH5hzBqv9cD9SlKpYoIzX60m2Cp/e FvYjWU5HazXXn0xHz2jRNyx5XY/++aFBg57sbl7pfmrpjvDjhtRRwOiGNYNx8OEiMS0P QOk4Jq32GnrS50JkJThK1O7bs1c2n8yZE6uZeVlsE+aaMRZTzceRvPKtegSH4qEQlsda ptbA== X-Gm-Message-State: AC+VfDynTN5GX0wF7K8fwpFXlwFPsElQu/YXsuVH0KNXdBHxDA5g10Ho eMEb7VmtVZDtKyd4mP3/LA3y9w== X-Google-Smtp-Source: ACHHUZ66w6gN6afzXEUhNGIYJlXlkcmFTjIO96e8ArI9LnEnVDhNQ8YF+0PLg9M1pCuReLWyEeRgIQ== X-Received: by 2002:a05:6a00:2d0b:b0:641:a6d:46b0 with SMTP id fa11-20020a056a002d0b00b006410a6d46b0mr849513pfb.22.1683167268316; Wed, 03 May 2023 19:27:48 -0700 (PDT) Received: from localhost.localdomain ([2408:8207:2421:6760:ecda:417a:920f:8647]) by smtp.gmail.com with ESMTPSA id c16-20020a62e810000000b00643355ff6a6sm1911751pfi.99.2023.05.03.19.27.41 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 May 2023 19:27:47 -0700 (PDT) From: Wenliang Wang To: mst@redhat.com, jasowang@redhat.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, zhengqi.arch@bytedance.com, willemdebruijn.kernel@gmail.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, xuanzhuo@linux.alibaba.com, Wenliang Wang Subject: [PATCH v4] virtio_net: suppress cpu stall when free_unused_bufs Date: Thu, 4 May 2023 10:27:06 +0800 Message-Id: <1683167226-7012-1-git-send-email-wangwenliang.1995@bytedance.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" For multi-queue and large ring-size use case, the following error occurred when free_unused_bufs: rcu: INFO: rcu_sched self-detected stall on CPU. Fixes: 986a4f4d452d ("virtio_net: multiqueue support") Signed-off-by: Wenliang Wang Acked-by: Michael S. Tsirkin --- v2: -add need_resched check. -apply same logic to sq. v3: -use cond_resched instead. v4: -add fixes tag --- drivers/net/virtio_net.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8d8038538fc4..a12ae26db0e2 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3560,12 +3560,14 @@ static void free_unused_bufs(struct virtnet_info *v= i) struct virtqueue *vq =3D vi->sq[i].vq; while ((buf =3D virtqueue_detach_unused_buf(vq)) !=3D NULL) virtnet_sq_free_unused_buf(vq, buf); + cond_resched(); } =20 for (i =3D 0; i < vi->max_queue_pairs; i++) { struct virtqueue *vq =3D vi->rq[i].vq; while ((buf =3D virtqueue_detach_unused_buf(vq)) !=3D NULL) virtnet_rq_free_unused_buf(vq, buf); + cond_resched(); } } =20 --=20 2.20.1