From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (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 50D2F6CDDF for ; Thu, 18 Apr 2024 07:33:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713425584; cv=none; b=iY3Y+rmD+8bc/aWHEzbz684HEqFwSmGjRWe2jkfzp3sFFCLr8ZK1IQfXMwtO5F1BWrcu3vjGzYLH1dX4keuBX1R5ICpQV+KcalT/AdXD2DibAZuPOtIrIJAdAMgbThS06Hh/R4Qzbu5dwU4m6XdCD4rWUrV8hrVgKT+cXVw9yO4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713425584; c=relaxed/simple; bh=Vmkft94CeXm1utOByhhbQk2dGA/tV6M1rzjjDE+0I8c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=o+kxfpvtCgsRn8qNcbRzDwPbcrv8wP9uXXC7gAPXJYgaWIOS8BUFArXILLwqgy42Lz1NPT8AfoDDUh+VE5tmhDR771JacB09DcuZngZwARG5zpVeI0WjHKLzf95tLzFgLqUXKJKIPSfdS0xboIBGyRsJlaaI3kpM6vSV4H5tCoQ= 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=RPT0ziME; arc=none smtp.client-ip=209.85.219.202 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="RPT0ziME" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-dc6ceade361so1338647276.0 for ; Thu, 18 Apr 2024 00:33:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1713425582; x=1714030382; 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=CZ6xGx7SCL04/2YLzMv5yVEEGM7jH9ixgUc8FyaXnxA=; b=RPT0ziMEuVv/5m40w3bN2j2W8Mi4BaQdqc/SJDe3jXP6r7rOOLvkmIOejwaP6h3NFC p5dusf2AgrrHmSPirNUof54oz1RTPXKJqkzdrSfjucY8z/K1fliBsZuyIz2dCQehmIHS h7LEdJmWZQbEAej3ErGXlvfkgW/YxDt+Sp9RbyOC7I0ntPejI+ESUKxueXLdcwjDnZJr nQID7UrBAT9eQ5tV2GwaTMNX40xt+sVoLgxJh3+B/TYTuK1aiz14/Hm017j1LTAfu/Tg Zu1zW2VQ+aDDBt4TYkQMKORUXi/KCMyPjh8lhfcxZ5kRtBq0FkEOy86aNzQbq6NuLbUd Q4jA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713425582; x=1714030382; 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=CZ6xGx7SCL04/2YLzMv5yVEEGM7jH9ixgUc8FyaXnxA=; b=Che5TmVSu/XcMfxYrekK6VNQ9Vj05jVhoNzHhBXGXRRm/vXvV9KS1/VCq8mcSIeoqm dofsImYBP18/3OOdVk8/codDjWvadNpkdaV+XSjpZslPdiatIMg10pY4A1z13JaqwlJb ihaUNC3C+/2ylfFSVwkykN1tvOhM0dEyCE7DBDGyEP/thCenE31H6wx58/qX8IrFXYfy 7Q4WJzPp5IRJVEWT76tzpPRVa5qXKqZrmX9jGivVIvjB6RVvQPcZ1+MI7z8GbT5KPb+E 0fbqmpJhor+C1cZsB1ruv0DDgrUTrnFedGIg0MTVWizDCTR1LG8AgYIH1fgee+nkl90F VmGg== X-Forwarded-Encrypted: i=1; AJvYcCW4Q4Ms/P/07uNaG4lvJvHoLVy7Vi5vAkjQR7H3Y/q5utqpEBJZk/Lrl49JxY5VSuB2mk4kvTGLA4zThv5L6WJerkmxzCPW X-Gm-Message-State: AOJu0Yzw0WQyp67GPeqo9sGITmXyQYbNHEMygK/dV7B8uEAmhtalvLHa 1gNvk6MMHMSExs29sxdkhXVbhwGKxaY6Xqri8BuKNFIJJnPkvaqXb83mQ7V7TyiwOs8jHdf9st7 6dKetjqGTGQ== X-Google-Smtp-Source: AGHT+IEOysJ/o2JBt8MpjJNm9RKDrsiBVxPKyHFe5ZUYV92MyyJUCqpq9VAa9N2e7j7ZoIutIhPrJs5UvToKXA== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a05:6902:c0e:b0:dc2:550b:a4f4 with SMTP id fs14-20020a0569020c0e00b00dc2550ba4f4mr511441ybb.1.1713425582523; Thu, 18 Apr 2024 00:33:02 -0700 (PDT) Date: Thu, 18 Apr 2024 07:32:41 +0000 In-Reply-To: <20240418073248.2952954-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240418073248.2952954-1-edumazet@google.com> X-Mailer: git-send-email 2.44.0.683.g7961c838ac-goog Message-ID: <20240418073248.2952954-8-edumazet@google.com> Subject: [PATCH v2 net-next 07/14] net_sched: sch_ets: implement lockless ets_dump() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Jamal Hadi Salim , Simon Horman , "=?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?=" , Cong Wang , Jiri Pirko , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" Instead of relying on RTNL, ets_dump() can use READ_ONCE() annotations, paired with WRITE_ONCE() ones in ets_change(). Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman --- net/sched/sch_ets.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c index 835b4460b44854a803d3054e744702022b7551f4..f80bc05d4c5a5050226e6cfd30fa951c0b61029f 100644 --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -646,7 +646,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, sch_tree_lock(sch); - q->nbands = nbands; + WRITE_ONCE(q->nbands, nbands); for (i = nstrict; i < q->nstrict; i++) { if (q->classes[i].qdisc->q.qlen) { list_add_tail(&q->classes[i].alist, &q->active); @@ -658,11 +658,11 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, list_del(&q->classes[i].alist); qdisc_tree_flush_backlog(q->classes[i].qdisc); } - q->nstrict = nstrict; + WRITE_ONCE(q->nstrict, nstrict); memcpy(q->prio2band, priomap, sizeof(priomap)); for (i = 0; i < q->nbands; i++) - q->classes[i].quantum = quanta[i]; + WRITE_ONCE(q->classes[i].quantum, quanta[i]); for (i = oldbands; i < q->nbands; i++) { q->classes[i].qdisc = queues[i]; @@ -676,7 +676,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, for (i = q->nbands; i < oldbands; i++) { qdisc_put(q->classes[i].qdisc); q->classes[i].qdisc = NULL; - q->classes[i].quantum = 0; + WRITE_ONCE(q->classes[i].quantum, 0); q->classes[i].deficit = 0; gnet_stats_basic_sync_init(&q->classes[i].bstats); memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats)); @@ -733,6 +733,7 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb) struct ets_sched *q = qdisc_priv(sch); struct nlattr *opts; struct nlattr *nest; + u8 nbands, nstrict; int band; int prio; int err; @@ -745,21 +746,22 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb) if (!opts) goto nla_err; - if (nla_put_u8(skb, TCA_ETS_NBANDS, q->nbands)) + nbands = READ_ONCE(q->nbands); + if (nla_put_u8(skb, TCA_ETS_NBANDS, nbands)) goto nla_err; - if (q->nstrict && - nla_put_u8(skb, TCA_ETS_NSTRICT, q->nstrict)) + nstrict = READ_ONCE(q->nstrict); + if (nstrict && nla_put_u8(skb, TCA_ETS_NSTRICT, nstrict)) goto nla_err; - if (q->nbands > q->nstrict) { + if (nbands > nstrict) { nest = nla_nest_start(skb, TCA_ETS_QUANTA); if (!nest) goto nla_err; - for (band = q->nstrict; band < q->nbands; band++) { + for (band = nstrict; band < nbands; band++) { if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND, - q->classes[band].quantum)) + READ_ONCE(q->classes[band].quantum))) goto nla_err; } @@ -771,7 +773,8 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb) goto nla_err; for (prio = 0; prio <= TC_PRIO_MAX; prio++) { - if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, q->prio2band[prio])) + if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, + READ_ONCE(q->prio2band[prio]))) goto nla_err; } -- 2.44.0.683.g7961c838ac-goog