From patchwork Thu Sep 9 14:08:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12483189 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC80AC433EF for ; Thu, 9 Sep 2021 13:59:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4B616127A for ; Thu, 9 Sep 2021 13:59:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244224AbhIIOBF (ORCPT ); Thu, 9 Sep 2021 10:01:05 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:15400 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354430AbhIIN7c (ORCPT ); Thu, 9 Sep 2021 09:59:32 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4H50qH03yczQslG; Thu, 9 Sep 2021 21:54:19 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.8; Thu, 9 Sep 2021 21:58:20 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Thu, 9 Sep 2021 21:58:20 +0800 From: Yu Kuai To: , CC: , , , , Subject: [RFC PATCH] blk-throttle: enable io throttle for root in cgroup v2 Date: Thu, 9 Sep 2021 22:08:15 +0800 Message-ID: <20210909140815.2600858-1-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org We want to limit the overall iops/bps of the device in cgroup v2, however "io.max" or "io.min" do not exist in root cgroup currently, which makes it impossible. This patch enables io throttle for root cgroup: - enable "io.max" and "io.min" in root - don't skip root group in tg_iops_limit() and tg_bps_limit() - don't skip root group in tg_conf_updated() I'm not sure why this feature is disabled in the first place, is there any problem or design constraint? Signed-off-by: Yu Kuai --- block/blk-throttle.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 55c49015e533..fffe072de538 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -302,9 +302,6 @@ static uint64_t tg_bps_limit(struct throtl_grp *tg, int rw) struct throtl_data *td; uint64_t ret; - if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent) - return U64_MAX; - td = tg->td; ret = tg->bps[rw][td->limit_index]; if (ret == 0 && td->limit_index == LIMIT_LOW) { @@ -332,9 +329,6 @@ static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw) struct throtl_data *td; unsigned int ret; - if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent) - return UINT_MAX; - td = tg->td; ret = tg->iops[rw][td->limit_index]; if (ret == 0 && tg->td->limit_index == LIMIT_LOW) { @@ -1430,9 +1424,8 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global) struct throtl_grp *parent_tg; tg_update_has_rules(this_tg); - /* ignore root/second level */ - if (!cgroup_subsys_on_dfl(io_cgrp_subsys) || !blkg->parent || - !blkg->parent->parent) + /* ignore root level */ + if (!cgroup_subsys_on_dfl(io_cgrp_subsys) || !blkg->parent) continue; parent_tg = blkg_to_tg(blkg->parent); /* @@ -1771,7 +1764,6 @@ static struct cftype throtl_files[] = { #ifdef CONFIG_BLK_DEV_THROTTLING_LOW { .name = "low", - .flags = CFTYPE_NOT_ON_ROOT, .seq_show = tg_print_limit, .write = tg_set_limit, .private = LIMIT_LOW, @@ -1779,7 +1771,6 @@ static struct cftype throtl_files[] = { #endif { .name = "max", - .flags = CFTYPE_NOT_ON_ROOT, .seq_show = tg_print_limit, .write = tg_set_limit, .private = LIMIT_MAX,