From nobody Sun Nov 24 11:09:34 2024 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 BA1FB205E2D; Wed, 6 Nov 2024 16:02:38 +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=1730908958; cv=none; b=hxX/aS3MOZBzQak6EyA6mD93ywCQNPB96JkH6SetglQ69RpiwM4xu14LgBYeHdtoHVjpz+HZHSdR5bDWwDDtOwjyZ2CMryL2XAG0aVM/jlLNa/c2y9srt46MwpdEfdkugBZFllMBfxfhbvZZ6LiOKwGEWfEIJKrL8rzRwEoOGto= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730908958; c=relaxed/simple; bh=zfmB69Z3xb3CVeThnzwQWB10ZhWTFdBu117CVg5FG/w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TC/QF9GPJ18NujXyLGalYEQYSVRhF3yGKebRRXO8MeNlf4pYsNggOjD0Xue4vZ7HaoTZJjYPR8yuWqhNuqlpd7cDbvq/oJvj0EJtzX7/Xw5haI84Ut+ZDjJ1yThdxcI2Os4N9vQVlzkIDuKK9vnLTDJ/6D49X0FOPoUBHsiyQB4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=US3V2bxN; 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="US3V2bxN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6396C4CED6; Wed, 6 Nov 2024 16:02:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730908958; bh=zfmB69Z3xb3CVeThnzwQWB10ZhWTFdBu117CVg5FG/w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=US3V2bxNdIcig1wbdN+HySmruVB8hPDXtM5nntafT1NgPz6BofWBWeDtMh911JaVX pE3xrd/On3iWHRu623V2OMrfoj8D1BvulvJwMRysquB/hsYzqMOFq4m+tDBNXVqDM1 hReXw6tPEag6+1UWvoHoBB4DPEatnLtdJGxFz5bd0jNYctf741aJ+glllZBZ90YVMh uMq/VrUUbELRSoxyn5Y5hpXY36EfWjevdpC5cGo+N6IMqerSVUbU3fjHaP7w+fMQon aBMFDTXYZqJYsixOS5ZmFS+d6pgNA2jtuEXX+qZPepSW+LAKpZP929477fdf84wINK +/JHgtEVaUDKw== From: Frederic Weisbecker To: LKML Cc: "Paul E. McKenney" , Boqun Feng , Joel Fernandes , Josh Triplett , Lai Jiangshan , Mathieu Desnoyers , Neeraj Upadhyay , Steven Rostedt , Uladzislau Rezki , Zqiang , rcu , Frederic Weisbecker Subject: [PATCH 3/6] rcuscale: Add guest_os_delay module parameter Date: Wed, 6 Nov 2024 17:02:20 +0100 Message-ID: <20241106160223.42119-4-frederic@kernel.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20241106160223.42119-1-frederic@kernel.org> References: <20241106160223.42119-1-frederic@kernel.org> 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 Content-Type: text/plain; charset="utf-8" From: "Paul E. McKenney" This commit adds a guest_os_delay module parameter that extends warm-up and cool-down the specified number of seconds before and after the series of test runs. This allows the data-collection intervals from any given rcuscale guest OSes to line up with active periods in the other rcuscale guest OSes, and also allows the thermal warm-up period required to obtain consistent results from one test to the next. Signed-off-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker --- kernel/rcu/refscale.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index 25910ebe95c0..c8374760e003 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -75,6 +75,9 @@ MODULE_PARM_DESC(scale_type, "Type of test (rcu, srcu, re= fcnt, rwsem, rwlock."); torture_param(int, verbose, 0, "Enable verbose debugging printk()s"); torture_param(int, verbose_batched, 0, "Batch verbose debugging printk()s"= ); =20 +// Number of seconds to extend warm-up and cool-down for multiple guest OS= es +torture_param(long, guest_os_delay, 0, + "Number of seconds to extend warm-up/cool-down for multiple guest O= Ses."); // Wait until there are multiple CPUs before starting test. torture_param(int, holdoff, IS_BUILTIN(CONFIG_RCU_REF_SCALE_TEST) ? 10 : 0, "Holdoff time before test start (s)"); @@ -801,6 +804,18 @@ static void rcu_scale_one_reader(void) cur_ops->delaysection(loops, readdelay / 1000, readdelay % 1000); } =20 +// Warm up cache, or, if needed run a series of rcu_scale_one_reader() +// to allow multiple rcuscale guest OSes to collect mutually valid data. +static void rcu_scale_warm_cool(void) +{ + unsigned long jdone =3D jiffies + (guest_os_delay > 0 ? guest_os_delay * = HZ : -1); + + do { + rcu_scale_one_reader(); + cond_resched(); + } while (time_before(jiffies, jdone)); +} + // Reader kthread. Repeatedly does empty RCU read-side // critical section, minimizing update-side interference. static int @@ -957,6 +972,7 @@ static int main_func(void *arg) schedule_timeout_uninterruptible(1); =20 // Start exp readers up per experiment + rcu_scale_warm_cool(); for (exp =3D 0; exp < nruns && !torture_must_stop(); exp++) { if (torture_must_stop()) goto end; @@ -987,6 +1003,7 @@ static int main_func(void *arg) =20 result_avg[exp] =3D div_u64(1000 * process_durations(nreaders), nreaders= * loops); } + rcu_scale_warm_cool(); =20 // Print the average of all experiments SCALEOUT("END OF TEST. Calculating average duration per loop (nanoseconds= )...\n"); --=20 2.46.0