From nobody Tue Apr 7 19:07:43 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B40E7C4332F for ; Tue, 18 Oct 2022 12:19:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230078AbiJRMTx (ORCPT ); Tue, 18 Oct 2022 08:19:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229955AbiJRMTn (ORCPT ); Tue, 18 Oct 2022 08:19:43 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A55D412AC8; Tue, 18 Oct 2022 05:19:38 -0700 (PDT) Received: from kwepemi500016.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MsCXV5c7RzJn2j; Tue, 18 Oct 2022 20:16:58 +0800 (CST) Received: from huawei.com (10.174.178.129) by kwepemi500016.china.huawei.com (7.221.188.220) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 18 Oct 2022 20:19:36 +0800 From: Kemeng Shi To: , , CC: , , , Subject: [PATCH v2 3/5] blk-iocost: Trace vtime_base_rate instead of vtime_rate Date: Tue, 18 Oct 2022 20:19:30 +0800 Message-ID: <20221018121932.10792-4-shikemeng@huawei.com> X-Mailer: git-send-email 2.14.1.windows.1 In-Reply-To: <20221018121932.10792-1-shikemeng@huawei.com> References: <20221018121932.10792-1-shikemeng@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.129] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi500016.china.huawei.com (7.221.188.220) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Since commit ac33e91e2daca ("blk-iocost: implement vtime loss compensation") rename original vtime_rate to vtime_base_rate and current vtime_rate is original vtime_rate with compensation. The current rate showed in tracepoint is mixed with vtime_rate and vtime_base_rate: 1) In function ioc_adjust_base_vrate, the first trace_iocost_ioc_vrate_adj shows vtime_rate, the second trace_iocost_ioc_vrate_adj shows vtime_base_rate. 2) In function iocg_activate shows vtime_rate by calling TRACE_IOCG_PATH(iocg_activate... 3) In function ioc_check_iocgs shows vtime_rate by calling TRACE_IOCG_PATH(iocg_idle... Trace vtime_base_rate instead of vtime_rate as: 1) Before commit ac33e91e2daca ("blk-iocost: implement vtime loss compensation"), the traced rate is without compensation, so still show rate without compensation. 2) The vtime_base_rate is more stable while vtime_rate heavily depends on excess budeget on current period which may change abruptly in next period. Signed-off-by: Kemeng Shi Acked-by: Tejun Heo --- block/blk-iocost.c | 2 +- include/trace/events/iocost.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 9214733bbc14..b0991b52e3dd 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -977,7 +977,7 @@ static void ioc_adjust_base_vrate(struct ioc *ioc, u32 = rq_wait_pct, =20 if (!ioc->busy_level || (ioc->busy_level < 0 && nr_lagging)) { if (ioc->busy_level !=3D prev_busy_level || nr_lagging) - trace_iocost_ioc_vrate_adj(ioc, atomic64_read(&ioc->vtime_rate), + trace_iocost_ioc_vrate_adj(ioc, vrate, missed_ppm, rq_wait_pct, nr_lagging, nr_shortages); =20 diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h index 6d1626e7a4ce..af8bfed528fc 100644 --- a/include/trace/events/iocost.h +++ b/include/trace/events/iocost.h @@ -38,7 +38,7 @@ DECLARE_EVENT_CLASS(iocost_iocg_state, __assign_str(cgroup, path); __entry->now =3D now->now; __entry->vnow =3D now->vnow; - __entry->vrate =3D now->vrate; + __entry->vrate =3D iocg->ioc->vtime_base_rate; __entry->last_period =3D last_period; __entry->cur_period =3D cur_period; __entry->vtime =3D vtime; @@ -160,7 +160,7 @@ TRACE_EVENT(iocost_ioc_vrate_adj, =20 TP_fast_assign( __assign_str(devname, ioc_name(ioc)); - __entry->old_vrate =3D atomic64_read(&ioc->vtime_rate); + __entry->old_vrate =3D ioc->vtime_base_rate; __entry->new_vrate =3D new_vrate; __entry->busy_level =3D ioc->busy_level; __entry->read_missed_ppm =3D missed_ppm[READ]; --=20 2.30.0