From patchwork Wed Sep 4 14:39:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uladzislau Rezki X-Patchwork-Id: 13791043 Received: from mail-lj1-f180.google.com (mail-lj1-f180.google.com [209.85.208.180]) (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 68D801D88D8; Wed, 4 Sep 2024 14:39:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725460786; cv=none; b=Eud6CcDo15qvLaCZ/VTk+h6uzDMbPFy4XlXStnJkgl+Twdv0T5trDhfPndSXVhGeBGwLBoKjIiR+/vpVEvwg6Qnj/FSUx4TF2sOTXTNC7QpZf4tRgqa+3uktnAGnoVwcvhWsZFLbAxvsn7/EN34UYAXit5Hnbiiec3BsyA+7wAE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725460786; c=relaxed/simple; bh=CBcEZmdHobsvIOFA2N1uEHl30j3tCoArg6oCafX8kTQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=sL8nvxD5VEg8sxqZgdpP82hT+FAVnaFWJR/aFwUUxruLlDpWaokhlMMO27oMtYcoWlbx5rNhoIawiJIyW79zZ9Cr7cPbosLYizzbMKGxJluTKSB9IaOHlB06DHJmQEwY6qUVrEk2uPz4DHHi1nRAru5jVtcrbufTO4RarYK9Om4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Ebrt/+xT; arc=none smtp.client-ip=209.85.208.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ebrt/+xT" Received: by mail-lj1-f180.google.com with SMTP id 38308e7fff4ca-2f50966c469so76303511fa.3; Wed, 04 Sep 2024 07:39:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725460783; x=1726065583; 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=G1t2IMMdcOOGIGKMQPUq9EL3DGfWZ0NZj9kyQG6uBN4=; b=Ebrt/+xTe7YbPWzgau6ClgD12oHvwbUOiGbggqDfYYmvyrYVa1/OKp2upNYyEasuXf Rh8VlvTMqCzOP/Un4rrXrQaaY99Vd5vRkupUS9zimVOYHthTzHavrQE53mYxbKBxpET0 wvjJxjMh/4LtXfJJecA5w2Fe8g8/66jg33kk6jw/5mha7ezFPF+hLG+urjTMBs76rp5I GbaSU+w9kafZBSklgTTu9l6ZIPlN9pQQE3gYdApOmGUtQzwJ7eFZdAEqRXrUuhk1cJfS eEHhDpOYXGVCx7LFxp/jjJt+rkCiBiXAeSmYsS1mGRRuefpxo4rBe71clxT/5KJsdASS 0V1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725460783; x=1726065583; 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=G1t2IMMdcOOGIGKMQPUq9EL3DGfWZ0NZj9kyQG6uBN4=; b=B6L7w15zsOhIlTUquUHUdzzQoNrz/z/YW7+7fhkX7ujOqS0tcleMpV9lN3PEBMZW5G 5NfwVCfE6e19pPgJVCRyxcO/NGBTjAT6/xhCviydfZRQHCLn4XjL8mrh9ab0HF3zqgqB nbYIp0u6pMsKnLqZAkrp2t7GunaK18BP8rrhruo0kRtgaWIJ7BXugQ8/Gp2ZmZRkO2kR IVuX4FvK07h33FPnvS/r8X/+4N2MftE/wZyktQgl3aTSpIPjYnGLOh5Vo25BPHk5WQK2 mD5BTFpTDddvmFfrRfIqifv/jFhSikmEAEagW9Wyzb+YyortLFL/JVD7WhJ0+rag70k4 T9+w== X-Forwarded-Encrypted: i=1; AJvYcCVK3rHeD1pIVI2AVdvcuP8AsT8P+BrJu6+wx9VArAbwjtEqdw8R1svveUA09aR0lojlgZZ2Z737jpojDt0=@vger.kernel.org X-Gm-Message-State: AOJu0YwrZqbDldJIX1uxlAv3of62X5e+RCIelWJ7CC7p39951xiUIWr/ uM8MGJIXcXz9OhJH1aN9lNy/VnsbfPLGaPSa8/s/mYf+S8k1DDHK X-Google-Smtp-Source: AGHT+IH0O29+qz7GY07ruJee+XpqNAYTXOHfuN3834r5Eky87Axzph3QB/aTv59igeeyZvHdrCljhQ== X-Received: by 2002:a05:651c:b0c:b0:2f3:cabc:6158 with SMTP id 38308e7fff4ca-2f62903f7efmr106481481fa.11.1725460782353; Wed, 04 Sep 2024 07:39:42 -0700 (PDT) Received: from pc638.lan ([2001:9b1:d5a0:a500:2d8:61ff:fec9:d743]) by smtp.gmail.com with ESMTPSA id 38308e7fff4ca-2f65eb480absm1375591fa.51.2024.09.04.07.39.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Sep 2024 07:39:42 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: "Paul E . McKenney" Cc: RCU , LKML , Neeraj upadhyay , Boqun Feng , Joel Fernandes , Frederic Weisbecker , Vlastimil Babka , Uladzislau Rezki , Oleksiy Avramchenko Subject: [PATCH v2 2/2] rcu/kvfree: Switch to expedited version in slow path Date: Wed, 4 Sep 2024 16:39:38 +0200 Message-Id: <20240904143938.119964-3-urezki@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240904143938.119964-1-urezki@gmail.com> References: <20240904143938.119964-1-urezki@gmail.com> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 For a single argument and its slow path, switch to expedited version of synchronize_rcu(). This version is considered to be more faster, thus under a high memory pressure a slow path becoms more efficient. Note, latency-sensitive workloads should use rcutree.gp_normal=1, which will make that synchronize_rcu_expedited() act like a regular synchronize_rcu(), so no harm done to them. Signed-off-by: Uladzislau Rezki (Sony) --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 182772494cb0..87a64fcffa7f 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3856,7 +3856,7 @@ void kvfree_call_rcu(struct rcu_head *head, void *ptr) */ if (!success) { debug_rcu_head_unqueue((struct rcu_head *) ptr); - cond_synchronize_rcu_full(&old_snap); + cond_synchronize_rcu_expedited_full(&old_snap); kvfree(ptr); } }