From patchwork Wed Oct 9 18:07:19 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: 13829012 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 2ACE61E1C27; Wed, 9 Oct 2024 18:07:22 +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=1728497242; cv=none; b=ZU1tRaQNMz8w/Ovb545TLFgNF/Q0bSi5Kp3W3+FIC8r6NV6rszfkupDd+1BZjrk1DvTzMJeMXqwOWdU4pPBMP/L9IbyBkMZLhu6eYOpPiNOO2xQ7gMNoer7EE3Sf77OEi/GHkR3HaFEOGpVq67ndQ1IjCZdTzJQfsf+djLrkj68= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728497242; c=relaxed/simple; bh=Am8qbMwuc4d4Iuj/D9Siigqz78XzeMZGAjUM0tNr9Ok=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JfuGCpZj/V0cje+Kwk6WG+5AuUwf8TO2T7yFmEx2rWI2EJ4BwNkckviC0w3glJmvzCd4pAGXI0E4QCyVqJ22pVDXXrgmB9xpTQrdHcWWN2ufOj+6oSQfgyYu/j6zPp09aysWXcpOPwbdXoraUpuTN2gECDPaxzAbHqRlZDFqMdI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qvpQuhSg; 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="qvpQuhSg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D20A9C4CEE6; Wed, 9 Oct 2024 18:07:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728497241; bh=Am8qbMwuc4d4Iuj/D9Siigqz78XzeMZGAjUM0tNr9Ok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qvpQuhSgcrnfmB1VxjAkD2SLSay9WhILI/5HriHPtNESgCazoSBxu75AssIeIG2wN SM6uTRFf1it7J3XG4Lli+CW5p2/HYlsoLQRoGRNDDxm+vSFs01M0Wd3lsQUgTWxG9H ljfGH6kKV8qIBzopt78bS1rk9FBrDNtwGyioUgcs1p2eZizMvJShs6b4jRN8cTGVmY L6/9BW7aOJAc1v+Muq2Fmjw9L2RChw0C1AOPolRiIZHcCheArodrX9/L8xUuMMlf7T 6vNu3MR0QKp9CfGaC2b0XIdh1TgV2tN6RnBDSAuZI9ntgJVR36CM0uPOwA7CPBN9Hb dWKxCMy2zzvZQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 33CF9CE2325; Wed, 9 Oct 2024 11:07:21 -0700 (PDT) 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, "Paul E. McKenney" , Alexei Starovoitov , Andrii Nakryiko , Peter Zijlstra , Kent Overstreet , bpf@vger.kernel.org Subject: [PATCH rcu 12/12] refscale: Add srcu_read_lock_lite() support using "srcu-lite" Date: Wed, 9 Oct 2024 11:07:19 -0700 Message-Id: <20241009180719.778285-12-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: rcu@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 be66e5a67ee19..897d5b5494949 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -216,6 +216,36 @@ 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. @@ -1133,27 +1163,26 @@ 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, &sched_clock_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, + &sched_clock_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)