From patchwork Tue Oct 15 16:11:11 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: 13836679 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 EF88B1F76DD; Tue, 15 Oct 2024 16:11:14 +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=1729008675; cv=none; b=laFi3NAhqex4qZrQmPlCHD5vJs50+D8wcf/ailyez20TSKd5rb+ihtnJhG6sKvDGZxHN2PukdJAbFSDH60xX6jEM+y5efm+iTyE0gGO/rAFxIgQPbGT5tvWv7Ru2s0YiizIVtvHaWaKf5jFdVON00f0qNzxTdttH3/5sS92rpnk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729008675; c=relaxed/simple; bh=ShAY23PXWJnTwN9m3aELbGSryO452AQIXFVffiHUjJ8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=edC1hSAa87U7INZi/fDo6Y9MX5TrkcdP2PGXdisj5iI/ePQW4TQqoXUFPjrL8l8nKT8prwzQqDkivl9A+xg8tsjOYYNS94t6LPJ8vex1jAfngaIbqGYS8vDH4fYqbdpKELKdGCzRstfvB8gWo2bCUAI8ISSZj5wji92m4NLPIPM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JLTU9ovS; 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="JLTU9ovS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4B44C4CEF3; Tue, 15 Oct 2024 16:11:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729008674; bh=ShAY23PXWJnTwN9m3aELbGSryO452AQIXFVffiHUjJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JLTU9ovS7V5DQluJGRKqzRlmP20klBZWltdZIpdgvfxcg0+/eG4Cwaj0xEwHOUAtP /Ji4tT90mMEUhTGub0zGqCrKbSRtoU0ZcEkTlBPiwEUgJT3i7k+Q1uQK5hUmjME8AW a9+f43D+BOtWUeqpm3NgeL/Mj50NU6YTTGCwmXq4mz/vgAkDmNJvMlxQlNS60Rlg8k kW9uwTlFFSMXAy6/Xgx+GouyhP3baIHbf5FP6BUawXwrvTg+Q4AEwjLtCPi4H3evOx bjnrCixHk3GLKz0Si3mNEHHxCIswE1nf1dBxbRZ5TjMyKmSDrgDdce5q+4CCqW91Rg gVitZYy3/GhFA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id D7376CE1FD6; Tue, 15 Oct 2024 09:11:13 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" , Alexei Starovoitov , Andrii Nakryiko , Peter Zijlstra , Kent Overstreet , bpf@vger.kernel.org Subject: [PATCH rcu 14/15] refscale: Add srcu_read_lock_lite() support using "srcu-lite" Date: Tue, 15 Oct 2024 09:11:11 -0700 Message-Id: <20241015161112.442758-14-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This commit creates a new srcu-lite option for the refscale.scale_type module parameter that selects srcu_read_lock_lite() and srcu_read_unlock_lite(). Signed-off-by: Paul E. McKenney Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Peter Zijlstra Cc: Kent Overstreet Cc: --- kernel/rcu/refscale.c | 51 +++++++++++++++++++++++++++++++++---------- 1 file changed, 40 insertions(+), 11 deletions(-) diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index 0db9db73f57f2..09ee27ced2a78 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -212,6 +212,36 @@ static const struct ref_scale_ops srcu_ops = { .name = "srcu" }; +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. @@ -1082,27 +1112,26 @@ ref_scale_init(void) long i; int firsterr = 0; static const struct ref_scale_ops *scale_ops[] = { - &rcu_ops, &srcu_ops, RCU_TRACE_OPS RCU_TASKS_OPS &refcnt_ops, &rwlock_ops, - &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, &clock_ops, &jiffies_ops, - &typesafe_ref_ops, &typesafe_lock_ops, &typesafe_seqlock_ops, + &rcu_ops, &srcu_ops, &srcu_lite_ops, RCU_TRACE_OPS RCU_TASKS_OPS + &refcnt_ops, &rwlock_ops, &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, + &clock_ops, &jiffies_ops, &typesafe_ref_ops, &typesafe_lock_ops, + &typesafe_seqlock_ops, }; if (!torture_init_begin(scale_type, verbose)) return -EBUSY; for (i = 0; i < ARRAY_SIZE(scale_ops); i++) { - cur_ops = scale_ops[i]; - if (strcmp(scale_type, cur_ops->name) == 0) + cur_ops = scale_ops[i]; if (strcmp(scale_type, + cur_ops->name) == 0) break; } if (i == ARRAY_SIZE(scale_ops)) { - pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type); - pr_alert("rcu-scale types:"); - for (i = 0; i < ARRAY_SIZE(scale_ops); i++) + pr_alert("rcu-scale: invalid scale type: \"%s\"\n", + scale_type); pr_alert("rcu-scale types:"); for (i = 0; + i < ARRAY_SIZE(scale_ops); i++) pr_cont(" %s", scale_ops[i]->name); - pr_cont("\n"); - firsterr = -EINVAL; - cur_ops = NULL; + pr_cont("\n"); firsterr = -EINVAL; cur_ops = NULL; goto unwind; } if (cur_ops->init)