From patchwork Thu Apr 18 07:32:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13634263 X-Patchwork-Delegate: kuba@kernel.org 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 D92EB7BB15 for ; Thu, 18 Apr 2024 07:33:07 +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=1713425589; cv=none; b=f8Q0i+YdiSV7mP3ALexAwjjC2QxJa4bSNbTCosK/OfHj4he/eud8eDMTjvtOz16A32GUOvdxpX2xMOQnQ58tJTLejEt4nNHG2Xwb1keEE4i8E8KN0NwGmmXq9u37yjCpmm8YIuIFtn4uqkxoP5mckBL48leRugTb0Q4cKi+5hJ4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713425589; c=relaxed/simple; bh=b9geUwdvrCVApCZ+TDEP6S5A5EH3GkVRnsbA9/mj3W4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=aIESwF9stZxoNM5EM5JPjzjdpjSakXl4c5kGDJUZ1RRn56TzWLRW10hp+sfzVoIEpN1+JrftzHE9NWr/xxRRBr9LzQzKL2AEptpaxC1k1yyOXcbxvZjY2NuSrIL1YsA5TjGnAFSr4RkReB2mN3pbV1we5ydS0xu/0J3YaChtmXc= 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=R0hIawiQ; 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="R0hIawiQ" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-de46620afd7so775770276.0 for ; Thu, 18 Apr 2024 00:33:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1713425587; x=1714030387; 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=JcvxTE64aBwZTgLCzhIFcmEI8tlRcvvT0NRZ+mhM1Bc=; b=R0hIawiQjZLuoe4par7zicOgpTrY14qHbDLCbmtk8CUCWKOsGoqhV5Cu6GByPKfGjH q0hqSApVJLK28pb5wt9q4nWi6nrtUlY0ciP9NGx4oG1hpgFKPrsZiyxXCUJrWEXwROgV g9vlc1fsALJOSuRs01YeLRED8Iqj8LKdyhmjLLaSF1eXsRg3CuLxhsYXKbnNQG2vLtgD 0qRdm27NXVUeYjLHo2uhGNmPcTZd9LTWci5PX/ENV88kQmFza3hJckDWRZ4hw0ubjCMK tcfCa6AZ55RP/nXULkYqmDPOENxEJxETC9Q4mue88JvF/o6A0ekBNaqeyBjT6sgfRWz0 AiKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713425587; x=1714030387; 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=JcvxTE64aBwZTgLCzhIFcmEI8tlRcvvT0NRZ+mhM1Bc=; b=NCRCdj+fJUiliaHZ10VomAR+ZNYN01Hk0KphLIQkT15w8+BYh2ntD0yjCQIdFjtP8P 2oUlycC1SJeRD/hBSZU+C9yrDJuAt6qSebULbic/Cwb7G/qoNtNjWVvkanHSqnbZcX+4 iKjB10aIkp1G7OLwvwaBgQ4bxvISOS6brHfJe54W5xVAcvzehlvYXpl46cmQklGgeWiA BEyQwaCPM3xqiwoP7WMMm1xcJfAjURY5TxtpEHOSuzUgx72ojE0/wG1nVMOATf/VUFWU E4pKcQm0y8afBh1Mhi7DiXOqdMZVLSgz27JgokYlRET7KnW1shYkoeYpwZUYvF9rCX3l 0w+Q== X-Forwarded-Encrypted: i=1; AJvYcCUtYV9UfIl7JlEV2RWZXc5U+Abj6SkFgaZyifGZykc/Fz3ytYKs2/2cYGdbREq3YghvLwL1KrDnD/5MtrIrMP4vxe7566V/ X-Gm-Message-State: AOJu0YxFVoI1v4QmCVH3Lsb86ZwTeGhz9Ifw7s+Rx4qnITsMCPulh9yI 2iuqbhv81nDneaNeO45uA4msk0XMPSIw4Iw71WId1UL22y5Mji8E6dZNK5GRaEhd628UkpkVEO5 6PgawmwFU6w== X-Google-Smtp-Source: AGHT+IELn3i+Y2Ad7iHrb4eX+JhyqQnWx+5HibSai60IL32eTAFN2QkFiqSgLa1BdsUyI4ZaaMhSyABmBj+2Tg== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a25:d352:0:b0:dcd:c091:e86 with SMTP id e79-20020a25d352000000b00dcdc0910e86mr197710ybf.13.1713425587057; Thu, 18 Apr 2024 00:33:07 -0700 (PDT) Date: Thu, 18 Apr 2024 07:32:44 +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: <20240418073248.2952954-11-edumazet@google.com> Subject: [PATCH v2 net-next 10/14] net_sched: sch_fq_pie: implement lockless fq_pie_dump() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Jamal Hadi Salim , Simon Horman , " =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= " , Cong Wang , Jiri Pirko , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet X-Patchwork-Delegate: kuba@kernel.org Instead of relying on RTNL, fq_pie_dump() can use READ_ONCE() annotations, paired with WRITE_ONCE() ones in fq_pie_change(). Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman --- net/sched/sch_fq_pie.c | 61 +++++++++++++++++++++++------------------- 1 file changed, 34 insertions(+), 27 deletions(-) diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index 358cf304f4c91203749bac10f6e9154eda0a3778..c38f33ff80bde74cfe33de7558f66e5962ffe56b 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -299,8 +299,8 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, if (tb[TCA_FQ_PIE_LIMIT]) { u32 limit = nla_get_u32(tb[TCA_FQ_PIE_LIMIT]); - q->p_params.limit = limit; - sch->limit = limit; + WRITE_ONCE(q->p_params.limit, limit); + WRITE_ONCE(sch->limit, limit); } if (tb[TCA_FQ_PIE_FLOWS]) { if (q->flows) { @@ -322,39 +322,45 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, u32 target = nla_get_u32(tb[TCA_FQ_PIE_TARGET]); /* convert to pschedtime */ - q->p_params.target = - PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC); + WRITE_ONCE(q->p_params.target, + PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC)); } /* tupdate is in jiffies */ if (tb[TCA_FQ_PIE_TUPDATE]) - q->p_params.tupdate = - usecs_to_jiffies(nla_get_u32(tb[TCA_FQ_PIE_TUPDATE])); + WRITE_ONCE(q->p_params.tupdate, + usecs_to_jiffies(nla_get_u32(tb[TCA_FQ_PIE_TUPDATE]))); if (tb[TCA_FQ_PIE_ALPHA]) - q->p_params.alpha = nla_get_u32(tb[TCA_FQ_PIE_ALPHA]); + WRITE_ONCE(q->p_params.alpha, + nla_get_u32(tb[TCA_FQ_PIE_ALPHA])); if (tb[TCA_FQ_PIE_BETA]) - q->p_params.beta = nla_get_u32(tb[TCA_FQ_PIE_BETA]); + WRITE_ONCE(q->p_params.beta, + nla_get_u32(tb[TCA_FQ_PIE_BETA])); if (tb[TCA_FQ_PIE_QUANTUM]) - q->quantum = nla_get_u32(tb[TCA_FQ_PIE_QUANTUM]); + WRITE_ONCE(q->quantum, nla_get_u32(tb[TCA_FQ_PIE_QUANTUM])); if (tb[TCA_FQ_PIE_MEMORY_LIMIT]) - q->memory_limit = nla_get_u32(tb[TCA_FQ_PIE_MEMORY_LIMIT]); + WRITE_ONCE(q->memory_limit, + nla_get_u32(tb[TCA_FQ_PIE_MEMORY_LIMIT])); if (tb[TCA_FQ_PIE_ECN_PROB]) - q->ecn_prob = nla_get_u32(tb[TCA_FQ_PIE_ECN_PROB]); + WRITE_ONCE(q->ecn_prob, + nla_get_u32(tb[TCA_FQ_PIE_ECN_PROB])); if (tb[TCA_FQ_PIE_ECN]) - q->p_params.ecn = nla_get_u32(tb[TCA_FQ_PIE_ECN]); + WRITE_ONCE(q->p_params.ecn, + nla_get_u32(tb[TCA_FQ_PIE_ECN])); if (tb[TCA_FQ_PIE_BYTEMODE]) - q->p_params.bytemode = nla_get_u32(tb[TCA_FQ_PIE_BYTEMODE]); + WRITE_ONCE(q->p_params.bytemode, + nla_get_u32(tb[TCA_FQ_PIE_BYTEMODE])); if (tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]) - q->p_params.dq_rate_estimator = - nla_get_u32(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]); + WRITE_ONCE(q->p_params.dq_rate_estimator, + nla_get_u32(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR])); /* Drop excess packets if new limit is lower */ while (sch->q.qlen > sch->limit) { @@ -471,22 +477,23 @@ static int fq_pie_dump(struct Qdisc *sch, struct sk_buff *skb) return -EMSGSIZE; /* convert target from pschedtime to us */ - if (nla_put_u32(skb, TCA_FQ_PIE_LIMIT, sch->limit) || - nla_put_u32(skb, TCA_FQ_PIE_FLOWS, q->flows_cnt) || + if (nla_put_u32(skb, TCA_FQ_PIE_LIMIT, READ_ONCE(sch->limit)) || + nla_put_u32(skb, TCA_FQ_PIE_FLOWS, READ_ONCE(q->flows_cnt)) || nla_put_u32(skb, TCA_FQ_PIE_TARGET, - ((u32)PSCHED_TICKS2NS(q->p_params.target)) / + ((u32)PSCHED_TICKS2NS(READ_ONCE(q->p_params.target))) / NSEC_PER_USEC) || nla_put_u32(skb, TCA_FQ_PIE_TUPDATE, - jiffies_to_usecs(q->p_params.tupdate)) || - nla_put_u32(skb, TCA_FQ_PIE_ALPHA, q->p_params.alpha) || - nla_put_u32(skb, TCA_FQ_PIE_BETA, q->p_params.beta) || - nla_put_u32(skb, TCA_FQ_PIE_QUANTUM, q->quantum) || - nla_put_u32(skb, TCA_FQ_PIE_MEMORY_LIMIT, q->memory_limit) || - nla_put_u32(skb, TCA_FQ_PIE_ECN_PROB, q->ecn_prob) || - nla_put_u32(skb, TCA_FQ_PIE_ECN, q->p_params.ecn) || - nla_put_u32(skb, TCA_FQ_PIE_BYTEMODE, q->p_params.bytemode) || + jiffies_to_usecs(READ_ONCE(q->p_params.tupdate))) || + nla_put_u32(skb, TCA_FQ_PIE_ALPHA, READ_ONCE(q->p_params.alpha)) || + nla_put_u32(skb, TCA_FQ_PIE_BETA, READ_ONCE(q->p_params.beta)) || + nla_put_u32(skb, TCA_FQ_PIE_QUANTUM, READ_ONCE(q->quantum)) || + nla_put_u32(skb, TCA_FQ_PIE_MEMORY_LIMIT, + READ_ONCE(q->memory_limit)) || + nla_put_u32(skb, TCA_FQ_PIE_ECN_PROB, READ_ONCE(q->ecn_prob)) || + nla_put_u32(skb, TCA_FQ_PIE_ECN, READ_ONCE(q->p_params.ecn)) || + nla_put_u32(skb, TCA_FQ_PIE_BYTEMODE, READ_ONCE(q->p_params.bytemode)) || nla_put_u32(skb, TCA_FQ_PIE_DQ_RATE_ESTIMATOR, - q->p_params.dq_rate_estimator)) + READ_ONCE(q->p_params.dq_rate_estimator))) goto nla_put_failure; return nla_nest_end(skb, opts);