From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f180.google.com (mail-yw1-f180.google.com [209.85.128.180]) (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 182BA4CB2E for ; Fri, 15 Mar 2024 19:55:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710532517; cv=none; b=JH2gbR7KeeH4b0SVs4QtxkBXHRu44EfK5SGrXB8hPF/SkCnitmQN8lzJLUrEOuagxG+0wuBHgGZQJFX5faASEZ1+dCk4WIQlVr1f0oPPk8VLpfP30QfMKf+ZHBoz9cvQMxmJdSILAC50fbokwfvNYvihus9NbYnKoik0lw5RgNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710532517; c=relaxed/simple; bh=WZXQ3n6OAHQk56baal6CzZ+snXfrxRm2xjx8a0VoWYc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GuntBKWnjrqzQNqh/+URQbC5TSe+2PDgtx6qgGAMJx7GTZDH7DEMnrrAdUzSFSMuD9apfbMG6swiPCgw2DkGcKI5p1uKm9UG9DEjgOwID9HSQhtDGhkMpcUULkC7WGoMi5Yg9k9FM3XM7cjoQCZS7zviL1aaAHjGDZw6pmfgRPE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com; spf=pass smtp.mailfrom=cloudflare.com; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b=B8iM9QDV; arc=none smtp.client-ip=209.85.128.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="B8iM9QDV" Received: by mail-yw1-f180.google.com with SMTP id 00721157ae682-60a057b6601so24691887b3.2 for ; Fri, 15 Mar 2024 12:55:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google09082023; t=1710532512; x=1711137312; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=JuTpc8vOHdn72vm+nW+iFZ+lBgZnpQ42Xv3ej2YV4rQ=; b=B8iM9QDVZLZoUQZ8+NLabWS5GVaGI8Isyl0UZeZNi6c7bxWMDdD9oOzjKm+InlbPtd nLtyh/PmJjVYabW8/ArekKixTswp0SJY9jxQLAy4uANQmBoi4FNZ1kEf5v58iLn+lflE cvSy0WnZRUsVqeCOG8yHqRq/VircQ3NdY/VOZD652Ya6yioJSClcndMz7Dx9NliOLBoB Uxa3CffXk6RcH7qLIVVsFtAeZ80I8beZvtT1jSBwmrg8C3oATJ0UfNWGDuf0HloYEFBq 7jlSpRAKasi40HOg/8QIJWkHFfbcSgJ3PWlIFSYEk+rSGMjFBxHTM8sjYzkGwID1e5oG xIOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710532512; x=1711137312; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=JuTpc8vOHdn72vm+nW+iFZ+lBgZnpQ42Xv3ej2YV4rQ=; b=mtmST8tcaGxW8sglQPvBNvEys2J59/Gt7lWXstIhzFRuNaNIPnCSZZttBolEMjGpUL zC5UbgtMJRbhWI789otsblwiKzInu9ph/yHBOh2SSnhQ4svOQE999+oCVj9B1qk2wv9Q BVO959JAVuIICApgNrCYxrXliwbT1pt85iZsXGAAy7L9YiHbcjaYHVVVOaqibS0ltRIG VkJ+oU28IclUUCFgcqRV+pouCpM2rE6N5TfYrdXB+0l35OujpxZ0vv0/wxNvLbuX1EQl YxFAtGa5nr9CIbHelQZInIDHiv0gLl/6rkHYa1Ah5PzvqR7TXK0kSBYLsZ3Sz1cXHQSa M/Xg== X-Gm-Message-State: AOJu0YyvinXBVaUVr6ARqgHFNcs0ndgkfrSD1vQWP9PvSqIcDqa1DMZ2 Qc/hVIRJ1/5wTbjl4cza7kSzP5p3SO9EVdAvGv100M/SHZLaK6ZQdxmnE3RmSHrUzTlf0lWTnk/ FGNk= X-Google-Smtp-Source: AGHT+IHyogcIr/Qsc9GsN9jZgtkStJ86LGPi25CEyZtC3+KaxMDzrcvpAOvf7tMwDDJPH7QLO3rHqA== X-Received: by 2002:a25:ea43:0:b0:dc6:ff12:1a21 with SMTP id o3-20020a25ea43000000b00dc6ff121a21mr5517436ybe.31.1710532512300; Fri, 15 Mar 2024 12:55:12 -0700 (PDT) Received: from debian.debian ([2a09:bac5:7a49:1046::19f:c]) by smtp.gmail.com with ESMTPSA id j6-20020ac86646000000b0042e2002ed12sm2251399qtp.57.2024.03.15.12.55.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Mar 2024 12:55:11 -0700 (PDT) Date: Fri, 15 Mar 2024 12:55:09 -0700 From: Yan Zhai To: netdev@vger.kernel.org Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jiri Pirko , Simon Horman , Daniel Borkmann , Lorenzo Bianconi , Coco Li , Wei Wang , Alexander Duyck , Hannes Frederic Sowa , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, bpf@vger.kernel.org, kernel-team@cloudflare.com, Joel Fernandes , "Paul E. McKenney" , Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= , Alexei Starovoitov , Steven Rostedt , mark.rutland@arm.com, Jesper Dangaard Brouer Subject: [PATCH v4 net 3/3] bpf: report RCU QS in cpumap kthread Message-ID: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: When there are heavy load, cpumap kernel threads can be busy polling packets from redirect queues and block out RCU tasks from reaching quiescent states. It is insufficient to just call cond_resched() in such context. Periodically raise a consolidated RCU QS before cond_resched fixes the problem. Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP") Reviewed-by: Jesper Dangaard Brouer Signed-off-by: Yan Zhai --- kernel/bpf/cpumap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index ef82ffc90cbe..8f1d390bcbde 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -262,6 +262,7 @@ static int cpu_map_bpf_prog_run(struct bpf_cpu_map_entry *rcpu, void **frames, static int cpu_map_kthread_run(void *data) { struct bpf_cpu_map_entry *rcpu = data; + unsigned long last_qs = jiffies; complete(&rcpu->kthread_running); set_current_state(TASK_INTERRUPTIBLE); @@ -287,10 +288,12 @@ static int cpu_map_kthread_run(void *data) if (__ptr_ring_empty(rcpu->queue)) { schedule(); sched = 1; + last_qs = jiffies; } else { __set_current_state(TASK_RUNNING); } } else { + rcu_softirq_qs_periodic(last_qs); sched = cond_resched(); } -- 2.30.2