From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f201.google.com (mail-qk1-f201.google.com [209.85.222.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 68548477E27 for ; Tue, 19 May 2026 09:46:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779183983; cv=none; b=ROwz9TPGCJGHOWkI3NUP7cVJA+oYAsWzhHbyAVQwdQL0hYXzsbGBEkden7zm12V/fLNr5mkxzUVgYVZ8GOr/Cm9emTP4212Zhta2zlUYPs0iqUFwmAczo/gtOsstDIGc+tDJ2jex/Tj9gcNUot2FNdV5BF1vvAZvPtNSDrJIV6Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779183983; c=relaxed/simple; bh=Ak5rBO7cWmzF2eSrDjc8qtvF/SdNr0c1rC9cn4VSXqs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=KimL4ldcSyrS/Z/VbbK7I0TBerYxyLS83sX8rmH282jEW1xW2JsDXrDfEKgIztteVmU2eZb2d9DtwF0eg0AMAOpUN4kipwUl/9VCfciNcG5pj2JrqtyVRR8JMJCTi9rdS47FDiajnVnGaiGHLh/IIp8pUsWZq6TMwaKXxSpkHus= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=vYehFi5X; arc=none smtp.client-ip=209.85.222.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vYehFi5X" Received: by mail-qk1-f201.google.com with SMTP id af79cd13be357-90f6c6101d5so836148285a.1 for ; Tue, 19 May 2026 02:46:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779183981; x=1779788781; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=u3Jy7T4AYlNjPz7/IipZnsJtYTGon4MGCeYMuavDyQc=; b=vYehFi5Xb0j49zAPYyQLnXi84SCMD6Ixhl9SKotiCv9UltlqFxATcrEA1J61hpQEar Dn1Fi9TD/JSKVVwVFqugoW9NwBQ1PaA/3FCj/ORxQo/cm3I5s/z2gAOdOe8E+3wuXb9B zsEIRg/SGkrKjk4bTQUw2zsw3pW5k0RpQlQd7lPBQpc/nC2EE2S7PMYE9WBUjE6SGceB 3ywE38iqPOvcXUlND2P51Ty3SeB/LpVu7nt8vHUUY9tWWL25qrIo55o3M+ooKstC3Y9y 06sdF3jwL6sl1/8u7Tym1ITTJ1MQVmuw3OYkgJ04V+E8NTS4KGGoH03JxjlG5ZodF0eZ +AAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779183981; x=1779788781; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=u3Jy7T4AYlNjPz7/IipZnsJtYTGon4MGCeYMuavDyQc=; b=PX1c1h1DyU/Uk0fuqaFBZNJ1GyNwj4Huqxc3xZpokSrhFPFye56ToPxH3l3lprUeu9 7QCMEUHDat635RkqSpu+FmgcTuLHJKhISNWoiV8+Q7E7W6usJh3hS/WzPhgV2P2VuYu7 Zc95HzR6sw59lYtEpG4sXQtmopfEginojROk8Pym76Uno0S4xPh7EkAXCfWgdAuqjJ4p Upq5Y6ka4SMalUKuEkr+RMBlnaDCErZaY7mLnEWZq0gs9olFq/PErrcTkldhaFYQww33 efmvRbs4zPfZAbOkY7UKHNd02f8IgoowI8/q8pAuouit9Ul7BU+KFdB7uB997otRHYw/ mZXw== X-Forwarded-Encrypted: i=1; AFNElJ866kEtJQf2F68WRxJMrr78PbEzD0j3YTCPbV/JkR+8dda7qgoE6pT04hLFGQPB95GoXFzfOfQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yxg8yKeoQ5Zr3B0gMb6g2Be5x1kTb92AhZizeEw5zGXlD91Jj/F pkrqz1KV8dyURBahhC3Hlvw75L1yDSTgk0WoTKXTDaCoUrRPOSQXmalcyvMdA9OmeZgVXZEkzAa SlcmqqhKmhogw3g== X-Received: from qknrr1.prod.google.com ([2002:a05:620a:6781:b0:90f:c0d9:c6ef]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:620a:2683:b0:8ee:bae8:2bb8 with SMTP id af79cd13be357-911cf9e1f06mr2760992085a.36.1779183981116; Tue, 19 May 2026 02:46:21 -0700 (PDT) Date: Tue, 19 May 2026 09:46:17 +0000 In-Reply-To: <20260519094618.2632073-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260519094618.2632073-1-edumazet@google.com> X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: <20260519094618.2632073-2-edumazet@google.com> Subject: [PATCH net-next 1/2] net/sched: sch_drr: annotate data-races around cl->deficit From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Jamal Hadi Salim , Victor Nogueira , Jiri Pirko , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" drr_dump_class_stats() runs without qdisc spinlock held. Add missing READ_ONCE()/WRITE_ONCE() annotations around cl->deficit. Fixes: edb09eb17ed8 ("net: sched: do not acquire qdisc spinlock in qdisc/class stats dump") Signed-off-by: Eric Dumazet --- net/sched/sch_drr.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c index 3f6687fa9666257952be5d44f9e3460845fe2a40..7da8c7c8421b7f2477c7c07d3b5920b375ce029e 100644 --- a/net/sched/sch_drr.c +++ b/net/sched/sch_drr.c @@ -270,7 +270,7 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg, memset(&xstats, 0, sizeof(xstats)); if (qlen) - xstats.deficit = cl->deficit; + xstats.deficit = READ_ONCE(cl->deficit); if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 || gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 || @@ -362,7 +362,7 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, if (!cl_is_active(cl)) { list_add_tail(&cl->alist, &q->active); - cl->deficit = cl->quantum; + WRITE_ONCE(cl->deficit, cl->quantum); } qstats_backlog_add(sch, len); @@ -389,7 +389,7 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch) len = qdisc_pkt_len(skb); if (len <= cl->deficit) { - cl->deficit -= len; + WRITE_ONCE(cl->deficit, cl->deficit - len); skb = qdisc_dequeue_peeked(cl->qdisc); if (unlikely(skb == NULL)) goto out; @@ -403,7 +403,7 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch) return skb; } - cl->deficit += cl->quantum; + WRITE_ONCE(cl->deficit, cl->deficit + cl->quantum); list_move_tail(&cl->alist, &q->active); } out: -- 2.54.0.563.g4f69b47b94-goog