From nobody Tue Sep 9 21:28:52 2025 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2DF2718AFF for ; Mon, 8 Sep 2025 00:32:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757291531; cv=none; b=WDuKv4THBfPkWIT1Q3SmeuIDU4gJ+INjLLbEOYHiH++wU0KMKl3aLoYvmpvRvfijNPtOopwiGTBfdOKlC4pR/9cbBy+gkfhRKV/uerdMDgSgvdin+zkDg2/6Fc6oLt+mzCVR7cv+RUdYt5HiZUl/xdFdTfJO75CiO/teSNdnaww= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757291531; c=relaxed/simple; bh=5QKsspVif7bTrYaXP3FasAnwvrnmS/iu0NY6fV7OK0c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=gvlhvJljzC/a+zw9K0Lj7vbRCzOlU/GVZyUXmv8Nw4GuhSGreoHnkSRzyaEsGyUsfjPUsS79o6UDNbFp9FNieUFpNPTPOWCHH3BpQZs/DlPE0c2gJ0ybvwMOZJh/1x/2Czx/K3NhVaDUNAMHIvg4LUZeLj97YWcXVymGsPOCc1g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Zya+nmmb; arc=none smtp.client-ip=91.218.175.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Zya+nmmb" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1757291520; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=V84IucEUJyCvbiT+ZRJpmbheHpQNezq37q7p3Eb6jMg=; b=Zya+nmmb7/SLrAgIGuwQZL4zv4do2oePvoALMwGotmLIPGKS1TXo0e920NVfjCVh0jcTNK NHKGhafcpslhaidvLJtiMZSyWvh2h0k1INsOl8m/oMAHQDkDYpBar4gXJAIgJYyDZQFhpZ 5hZNhwVfCGLUn7xAYiUfEQABfuHMJk4= From: Zqiang To: paulmck@kernel.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com, boqun.feng@gmail.com, urezki@gmail.com Cc: qiang.zhang@linux.dev, rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] srcu/tiny: Remove preempt_disable/enable() in srcu_gp_start_if_needed() Date: Mon, 8 Sep 2025 08:31:55 +0800 Message-ID: <20250908003155.557070-1-qiang.zhang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Currently, the srcu_gp_start_if_needed() is always be invoked in preempt disable's critical section, this commit therefore remove redundant preempt_disable/enable() in srcu_gp_start_if_needed(). Fixes: 65b4a59557f6 ("srcu: Make Tiny SRCU explicitly disable preemption") Signed-off-by: Zqiang --- kernel/rcu/srcutiny.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index b52ec45698e8..417bd0e4457c 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -181,10 +181,8 @@ static void srcu_gp_start_if_needed(struct srcu_struct= *ssp) { unsigned long cookie; =20 - preempt_disable(); // Needed for PREEMPT_LAZY cookie =3D get_state_synchronize_srcu(ssp); if (ULONG_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie)) { - preempt_enable(); return; } WRITE_ONCE(ssp->srcu_idx_max, cookie); @@ -194,7 +192,6 @@ static void srcu_gp_start_if_needed(struct srcu_struct = *ssp) else if (list_empty(&ssp->srcu_work.entry)) list_add(&ssp->srcu_work.entry, &srcu_boot_list); } - preempt_enable(); } =20 /* --=20 2.48.1