From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.116 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793967872; b=Ba0XCFzmnOMt+oa1vmBQn5zBo8aBrZNzafj1a1NsD+bRPDGCrAOG2w04WQKdoYUMf1WN suGJNb3H0am+uQ1sFO09bEpAjL4TzeSNlTNkiGtjUEuE18+T0UBpLVgH8hVJDD6wBBXM+ EnQIt2ntqjVUQXKIRdbtQWooazIMMGjWO5M2SkPaMuaKnnt3cuekaP4Fzj/hJIHfK0tPP HGlqb9KAaTJ7GsRNgRJNKI693zCLqO1ZnXjZKtrkXIDZzsOewWQw55GhqlOer5reNmIRF HzXibUQ70oCcAfXA6pqRRoqcS4Szbb5qSEx4J7gJvB4Q2Lgdhe1cKvOYEYxqCMW/xaA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793967872; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=M7w+lcMd84BXD94nDGUSUppgCI2FJeMKCZLUv/sEq4k=; b=AsIAKqtxa2Ku5Qgv8SKTLEWYwPH2FOqxulIE5bgPoeDyShpU3mKoImllYU75vKiLuwpu MvrEvJ5ZdJy4RIou7fkZfYzYdh97MXLq9/7TIqWpIX3e2psQwAPTr3pQRjZyPC0VIpnar QetlN9zhmbD9Jh77fOisIHYOyu+5uPL0RLcaIdi1zptwqm8TY+EiNVZvyrIMkVksx1yH8 0ZZyIHn9F2276IoW4KZGYZGMxZNtc7eGR7Y7KnHEB3ORtMzy6mx3uBMQYEarW16fkoDV4 pgs64YP8a7KteRx87R9UyV+pceF6oXdvRwybntJyx40CM+t9NHawIOIuEi7+0Qe4fZA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=xYK5G+il; arc=none smtp.remote-ip=95.215.58.116 Received: from mta1.migadu.com (out-116.mta1.migadu.com [95.215.58.116]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 26B75606A335 for ; Fri, 6 Nov 2026 12:24:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 26B75606A335 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=xYK5G+il X-Envelope-To: bpf@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=I+VC3zuj70/Ggc+NF+80ECDOvzawMqRE1+AbZCfHpoU=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793967870; v=1; x=1794572670; b=xYK5G+ilob8/el9FwfbpiyHs544QedxsjztuIFqX6OmAvjkI0nURA+DZjhHGJZG9ds7p+8lH WEkjOPpz6KIt81psN6oyqbj8y+e/uSewVm7m7QBg9UWdWkGa06tRsn86kVkfzTtEhg0ZnXBm/nq sSQIQlXARcU7o+GhIwRxGFM0= X-Envelope-To: bpf@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 3cf06a67f39bf5f0; Fri, 06 Nov 2026 12:24:30 +0000 X-Mizu-Trace-ID: 3cf06a67f39bf5f0 X-Migadu-Flow: FLOW_OUT From: Tao Cui To: tj@kernel.org, josef@toxicopanda.com, axboe@kernel.dk, alexei.starovoitov@gmail.com Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, linux-kselftest@vger.kernel.org, cui.tao@linux.dev, cuitao@kylinos.cn, ameryhung@gmail.com Subject: [RFC PATCH v13 2/4] blk-iocost: add iocost_ioc_tick tracepoint for per-period device summary Date: Fri, 6 Nov 2026 20:23:54 +0800 Message-ID: <20261106122356.3224638-3-cui.tao@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261106122356.3224638-1-cui.tao@linux.dev> References: <20261106122356.3224638-1-cui.tao@linux.dev> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tao Cui Add iocost_ioc_tick, emitted once per period from ioc_timer_fn() with the overall controller state: period_us, vrate, busy_level, active iocg count and usage percentage. busy_level, cur_period, nr_active and usage_us_sum are complete at the emission point. usage is wall time over wall time, summed over iocgs, and is not capped at 100. vrate and period_us reflect the current controller state, which an io.cost.qos write may have changed mid-period. The event fires every period the controller is running, including steady states, plus one final tick before the controller goes idle, so the transition to dormancy is directly visible. The active iocg count is only gathered when the tracepoint is enabled. Suggested-by: Tejun Heo Signed-off-by: Tao Cui --- MAINTAINERS | 1 + block/blk-iocost.c | 18 +++++++++++++++ include/trace/events/iocost.h | 43 +++++++++++++++++++++++++++++++++++ 3 files changed, 62 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index aa647f5d37dd..2000a38dbc9c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6852,6 +6852,7 @@ F: block/blk-iocost.c F: block/blk-iolatency.c F: block/blk-throttle.c F: include/linux/blk-cgroup.h +F: include/trace/events/iocost.h CONTROL GROUP - CPUSET M: Waiman Long diff --git a/block/blk-iocost.c b/block/blk-iocost.c index c3d195fe4a89..d2007b7b73bf 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2349,6 +2349,7 @@ static void ioc_timer_fn(struct timer_list *timer) struct ioc_now now; LIST_HEAD(surpluses); int nr_debtors, nr_shortages = 0, nr_lagging = 0; + int nr_active = 0; u64 usage_us_sum = 0; u32 ppm_rthr; u32 ppm_wthr; @@ -2546,6 +2547,23 @@ static void ioc_timer_fn(struct timer_list *timer) ioc->busy_level = clamp(ioc->busy_level, -1000, 1000); + /* + * busy_level, cur_period, nr_active and usage_us_sum are complete + * here. usage is wall time over wall time, summed over iocgs, and + * is not capped at 100. vrate and period_us reflect the current + * controller state, which an io.cost.qos write may have changed + * mid-period. Emit before the refresh and the period transition. + */ + if (trace_iocost_ioc_tick_enabled()) { + struct ioc_gq *active_iocg; + + list_for_each_entry(active_iocg, &ioc->active_iocgs, + active_list) + nr_active++; + + trace_iocost_ioc_tick(ioc, &now, nr_active, usage_us_sum); + } + ioc_adjust_base_vrate(ioc, rq_wait_pct, nr_lagging, nr_shortages, prev_busy_level, missed_ppm); diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h index eb711343ce4f..ea7ec3c1da5c 100644 --- a/include/trace/events/iocost.h +++ b/include/trace/events/iocost.h @@ -181,6 +181,49 @@ TRACE_EVENT(iocost_ioc_vrate_adj, ) ); +/* + * Periodic per-device summary, emitted once per period before the vrate + * adjustment and the period transition in ioc_timer_fn(). Unlike the + * state-change events above, this fires every period the controller is + * running, including steady states, and carries the overall controller state + * so basic monitoring doesn't require drgn. + */ +TRACE_EVENT(iocost_ioc_tick, + + TP_PROTO(struct ioc *ioc, const struct ioc_now *now, + int nr_active, u64 usage_us_sum), + + TP_ARGS(ioc, now, nr_active, usage_us_sum), + + TP_STRUCT__entry ( + __string(devname, ioc_name(ioc)) + __field(u64, cur_period) + __field(u32, period_us) + __field(u64, vrate) + __field(int, busy_level) + __field(int, nr_active) + __field(u64, usage_pct) + ), + + TP_fast_assign( + __assign_str(devname); + __entry->cur_period = atomic64_read(&ioc->cur_period); + __entry->period_us = ioc->period_us; + __entry->vrate = ioc->vtime_base_rate; + __entry->busy_level = ioc->busy_level; + __entry->nr_active = nr_active; + __entry->usage_pct = now->now > ioc->period_at ? + div64_u64(usage_us_sum * 100, + now->now - ioc->period_at) : 0; + ), + + TP_printk("[%s] period=%llu:%uus vrate=%llu busy=%d active=%d usage=%llu%%", + __get_str(devname), __entry->cur_period, __entry->period_us, + __entry->vrate, __entry->busy_level, __entry->nr_active, + __entry->usage_pct + ) +); + TRACE_EVENT(iocost_iocg_forgive_debt, TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now, -- 2.53.0