From patchwork Tue Nov 28 08:00:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uladzislau Rezki X-Patchwork-Id: 13470582 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="htrmT2Wz" Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC55419D; Tue, 28 Nov 2023 00:00:40 -0800 (PST) Received: by mail-lf1-x130.google.com with SMTP id 2adb3069b0e04-50aaaf6e58fso7777336e87.2; Tue, 28 Nov 2023 00:00:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701158439; x=1701763239; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=XhGfiMA+FxwDjc7t0nt/AcmpjpbgCOpq64Uuwhjmwcc=; b=htrmT2WzhWPg7YEYgl2rpQyaKIWN33ZAih/zXMGkVoQ91n4WxzTqefDewirCLxdu/U pB9fVtemOF/W3UYMQSiZT05DnY5J9RYlnga4ZPmbmhaV6azq4mvE6Vn6hmOWIYv3zVLV QfSobqiY9MM08TmnGgkwwVL3k/ezTdNg0TOio01f7GiHtACtnlu4AkZvh8IWQKPmdloY LwVvBtEchYnKbdZijLZod2RYmBKta17QPfqqKDeZc0xLcjyZ/ouc/LNXb02abBDi1fh2 CoQsN6xgYTIoZ0il+7+SlOkloPU2ZADGyn/evKjIQfwr8AFU4QSwOvtjnimAOx60rS5R y3uA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701158439; x=1701763239; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=XhGfiMA+FxwDjc7t0nt/AcmpjpbgCOpq64Uuwhjmwcc=; b=Dipc1XNKHsfAR/hrNghEilNB2AjbwYjTM9KVtqaLTQFus61IYFzWMp4ZKBSRQ67kDb 96p346e3ZtIF+Vv6CX/pAjFBuV3wGBLmZGh2s4keaZpQh06cq7p+7jwbJsKzXUMym/N5 G9Q1stEB5Qvsb/whdlRL0wbuh4vKBZCmONw14/daZZsxHhUgQgZAJX7sm+xYS0p7afpN YgiGYBlEA5qEtJ6hUEZ/hzqZqP1k/ZNg5+axihGFyTmsP7B8JD+iwOP8qbNJbmpynHKm SvN1bcze80pbtKM5ZJ95j/TPteKr4OztHmPj5Ad6jW4VwrP49jp+A+L8RBRQper8OxkF GTqQ== X-Gm-Message-State: AOJu0Ywt3Ay4HQGPoeYzs0xPMLN8cKQa3lKaMBmBS+SLuUUm10y0skr1 q8E6QpRiRPo7vVOLmDnbDOc7Hu7jtWs= X-Google-Smtp-Source: AGHT+IE/LYlsTrWkg7977AH0uge/4rfAnM8l3c5uoqkgIxckVASEsPJezyjKjS17I73AR9ZDfBbhxA== X-Received: by 2002:ac2:563b:0:b0:509:145c:6a49 with SMTP id b27-20020ac2563b000000b00509145c6a49mr8953744lff.42.1701158438666; Tue, 28 Nov 2023 00:00:38 -0800 (PST) Received: from pc638.lan ([155.137.26.201]) by smtp.gmail.com with ESMTPSA id o16-20020ac24bd0000000b004fe202a5c7csm1765501lfq.135.2023.11.28.00.00.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Nov 2023 00:00:38 -0800 (PST) From: "Uladzislau Rezki (Sony)" To: "Paul E . McKenney" Cc: RCU , Neeraj upadhyay , Boqun Feng , Hillf Danton , Joel Fernandes , LKML , Uladzislau Rezki , Oleksiy Avramchenko , Frederic Weisbecker Subject: [PATCH v3 3/7] doc: Add rcutree.rcu_normal_wake_from_gp to kernel-parameters.txt Date: Tue, 28 Nov 2023 09:00:29 +0100 Message-Id: <20231128080033.288050-4-urezki@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231128080033.288050-1-urezki@gmail.com> References: <20231128080033.288050-1-urezki@gmail.com> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This commit adds rcutree.rcu_normal_wake_from_gp description to the kernel-parameters.txt file. Signed-off-by: Uladzislau Rezki (Sony) --- Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 0a1731a0f0ef..65bfbfb09522 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4944,6 +4944,20 @@ this kernel boot parameter, forcibly setting it to zero. + rcutree.rcu_normal_wake_from_gp= [KNL] + Reduces a latency of synchronize_rcu() call. This approach + maintains its own track of synchronize_rcu() callers, so it + does not interact with regular callbacks because it does not + use a call_rcu[_hurry]() path. Please note, this is for a + normal grace period. + + How to enable it: + + echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp + or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1" + + Default is 0. + rcuscale.gp_async= [KNL] Measure performance of asynchronous grace-period primitives such as call_rcu().