From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4E4DC7482; Wed, 2 Jul 2025 00:23:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751415815; cv=none; b=SdmGiGPs9A01lUH6eRW9qpv35oaSmrUv+iCVP/5CK+pDHwGFPJBalG8H8z3WgXPnzrNgtRpHxz4y1oDYwstDk9aDGtdbkQZFFUwzPbdbAKOytb/2pHe1mUqkuWuf8u+eWdmNSWomUkh8+HiZ9vhnGOGR6I4LwbK8lmYKDOTRXcQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751415815; c=relaxed/simple; bh=EUI54hyyekscOlUf1kI6gFhpia6+94hPUVs8ZhSFkV4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZQE0PhEBKzbS3vNxlp+IGpigRXy9dLzHrYq3b1sVl8o5Am3pUkmaFy8hkcFg4xS3REE4rUwDtTsGaFT8vZAqlfRWgrfBoPeyFgYSs2HaAiuGdUHPgi7OxKI7xzFsDIy3YWpT81U0/t+0HJGE2ZHnUv9XrpsPzVfoBKKziNEwVJE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G8RAmerP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="G8RAmerP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9130C4CEEB; Wed, 2 Jul 2025 00:23:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751415814; bh=EUI54hyyekscOlUf1kI6gFhpia6+94hPUVs8ZhSFkV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G8RAmerPRzYla7Kx67NwHAizBqGltgF4pVXpU71nMmctvt+ztXxD++pfD6yXBaFuD 5IrwzHyYCYOaInOwlGNwo2ATo7iBlpNXD0izqhgYsKMEn1ifDMUgqz1JDZT/BHQQl6 R+rthcPiN+tk/banqyv2nFLhCDvf56+6mZ890XX2HLEZ2I4SilaLW+ltbf+WOx+wkk laat0zpWNVk/fAt4fTtD+/gIV1+dOM86gzRovtK/f1/RM5dayLQKdCQsUtWxmokmdG joQPdhepaoKYp/tzHr63mWLVYbcUH4ViqfMn4Ji3jzUCbe/RH5CEknva/ZaAxqiNGO 2QaqDtPiDtr+g== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 86FC9CE0E63; Tue, 1 Jul 2025 17:23:34 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, Christoph Hellwig , "Paul E. McKenney" Subject: [PATCH v2 1/5] torture: Remove support for SRCU-lite Date: Tue, 1 Jul 2025 17:23:26 -0700 Message-Id: <20250702002330.1074433-1-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <2994ade2-bd06-4ba7-bcc9-be4d0d15ea0c@paulmck-laptop> References: <2994ade2-bd06-4ba7-bcc9-be4d0d15ea0c@paulmck-laptop> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Because SRCU-lite is being replaced by SRCU-fast, this commit removes support for SRCU-lite from refscale.c. Both SRCU-lite and SRCU-fast provide faster readers by dropping the smp_mb() call from their lock and unlock primitives, but incur a pair of added RCU grace periods during the SRCU grace period. There is a trivial mapping from the SRCU-lite API to that of SRCU-fast, so there should be no transition issues. [ paulmck: Apply Christoph Hellwig feedback. ] Signed-off-by: Paul E. McKenney --- kernel/rcu/refscale.c | 32 +------------------------------- 1 file changed, 1 insertion(+), 31 deletions(-) diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index f11a7c2af778c..f4b2cea1cce5e 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -246,36 +246,6 @@ static const struct ref_scale_ops srcu_fast_ops = { .name = "srcu-fast" }; -static void srcu_lite_ref_scale_read_section(const int nloops) -{ - int i; - int idx; - - for (i = nloops; i >= 0; i--) { - idx = srcu_read_lock_lite(srcu_ctlp); - srcu_read_unlock_lite(srcu_ctlp, idx); - } -} - -static void srcu_lite_ref_scale_delay_section(const int nloops, const int udl, const int ndl) -{ - int i; - int idx; - - for (i = nloops; i >= 0; i--) { - idx = srcu_read_lock_lite(srcu_ctlp); - un_delay(udl, ndl); - srcu_read_unlock_lite(srcu_ctlp, idx); - } -} - -static const struct ref_scale_ops srcu_lite_ops = { - .init = rcu_sync_scale_init, - .readsection = srcu_lite_ref_scale_read_section, - .delaysection = srcu_lite_ref_scale_delay_section, - .name = "srcu-lite" -}; - #ifdef CONFIG_TASKS_RCU // Definitions for RCU Tasks ref scale testing: Empty read markers. @@ -1193,7 +1163,7 @@ ref_scale_init(void) long i; int firsterr = 0; static const struct ref_scale_ops *scale_ops[] = { - &rcu_ops, &srcu_ops, &srcu_fast_ops, &srcu_lite_ops, RCU_TRACE_OPS RCU_TASKS_OPS + &rcu_ops, &srcu_ops, &srcu_fast_ops, RCU_TRACE_OPS RCU_TASKS_OPS &refcnt_ops, &rwlock_ops, &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, &sched_clock_ops, &clock_ops, &jiffies_ops, &typesafe_ref_ops, &typesafe_lock_ops, &typesafe_seqlock_ops, -- 2.40.1