From patchwork Fri Oct 11 17:39:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13832857 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 AA813199234; Fri, 11 Oct 2024 17:39:12 +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=1728668352; cv=none; b=A+2AcAlftXlS7JAezocZ0kkpiNlIAbreRXEl8+2EVsGJCPhA4uHWPAMLZiTsFDcUEf37uN6G1cWH93BvgXq5w0s1CoLTFrLHH9nTiGlvtIa+cBS6i9RxBn4KjGKeBGEzY/A5Art5nzppVt7U4pt+w4w6gD2ZqwYmIs7u4XbJ7GY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728668352; c=relaxed/simple; bh=l2iFzEisCe9BnUPcYMgvs7xBLciJk1BGFnxZefE5tuE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=h+rpZApLrpYHEVXrBrHBy9ujjI1Jr1a+JOsrSkyn0fpqVhVGHqHraNtPh0oAnG9KIEgJW8Lo4DZ04fFCEdAc+6H/BCEatJ05k23+cKV5FqgV+/Ji3Ejeq6Ttm8k0Xvv0y91Tlw1sNl5X5oqvo9WeCe7LNPXT7fqesvlUKELeBdI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rTks7TOR; 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="rTks7TOR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F5B8C4CEC3; Fri, 11 Oct 2024 17:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728668352; bh=l2iFzEisCe9BnUPcYMgvs7xBLciJk1BGFnxZefE5tuE=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=rTks7TORLjEovbZm2khWddbwn6SZZz2C2y8U3HMCtPmZMaRchJLqhKW6Zwa+k6ZSJ 3yhcxmwRBSQtMoP4DeYzEYuK3PFo/Qv6BdpxGjKKp76Ds7QNagz5KhRML5D+7DYBrB 8MzoAEWZJPbXNX9J8flYil/h7Pgy57h5WCGR/2gX84CeXYPJWW86kuvgl60g4EU5dW EGKM4LYBK+95GxBam0a/MduPzpQL/UX5j957WK3iYRudtMN5lBqONm3hpfPQP1Xkpl SI6BQUUE8zSfiwZtzfHsHPL+KVFM/M2a4YktLi5SfL88BxoACiiE0Y1vZJ/bTBk+Qv eBIw/+7Z+D0tg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 10BB2CE0BB1; Fri, 11 Oct 2024 10:39:11 -0700 (PDT) Date: Fri, 11 Oct 2024 10:39:11 -0700 From: "Paul E. McKenney" To: frederic@kernel.org, rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org Subject: [PATCH v2 rcu 0/13] SRCU-lite changes for v6.13 Message-ID: <3b82ac1a-8786-4a27-8eff-ecc67b50dfb6@paulmck-laptop> Reply-To: paulmck@kernel.org References: Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Hello! This v2 series adds support and testing for srcu_read_lock_lite() and srcu_read_unlock_lite(), which avoid smp_mb(), but add a couple of synchronize_rcu() calls to the grace-period processing and may only be used where RCU is watching. 1. Rename srcu_might_be_idle() to srcu_should_expedite(). 2. Introduce srcu_gp_is_expedited() helper function. 3. Renaming in preparation for additional reader flavor. 4. Bit manipulation changes for additional reader flavor. 5. Standardize srcu_data pointers to "sdp" and similar. 6. Add srcu_read_lock_lite() and srcu_read_unlock_lite(). 7. Allow inlining of __srcu_read_{,un}lock_lite(). 8. Expand RCUTORTURE_RDR_MASK_[12] to eight bits. 9. Add reader_flavor parameter for SRCU readers. 10. Add srcu_read_lock_lite() support to rcutorture.reader_flavor. 11. Add light-weight SRCU scenario. 12. Add srcu_read_lock_lite() support using "srcu-lite". 13. Improve srcu_read_lock_lite() kernel-doc comment. Changes since v1: o Apply reviewed-by tag. o Link to performance data. o Add commit improving kernel-doc comment. o Pull out into separate branch to avoid dependency on an otherwise unrelated refscale commit. Thanx, Paul ------------------------------------------------------------------------ Documentation/admin-guide/kernel-parameters.txt | 4 b/Documentation/admin-guide/kernel-parameters.txt | 8 b/include/linux/srcu.h | 21 - b/include/linux/srcutree.h | 2 b/kernel/rcu/rcutorture.c | 28 - b/kernel/rcu/refscale.c | 51 ++ b/kernel/rcu/srcutree.c | 16 b/tools/testing/selftests/rcutorture/configs/rcu/CFLIST | 1 b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-L | 10 b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-L.boot | 3 b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot | 1 b/tools/testing/selftests/rcutorture/configs/rcu/TREE10 | 2 include/linux/srcu.h | 89 +++- include/linux/srcutree.h | 44 ++ kernel/rcu/rcutorture.c | 37 + kernel/rcu/srcutree.c | 207 ++++++----- 16 files changed, 363 insertions(+), 161 deletions(-)