From: Tejun Heo <tj@kernel.org>
To: Tao Cui <cui.tao@linux.dev>
Cc: josef@toxicopanda.com, axboe@kernel.dk, 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, cuitao@kylinos.cn,
ameryhung@gmail.com, alexei.starovoitov@gmail.com
Subject: Re: [PATCH 4/5] blk-iocost: add iocost_ioc_tick tracepoint for per-period device summary
Date: Wed, 28 Oct 2026 10:09:30 -1000 [thread overview]
Message-ID: <75384a99148fbd477e003453718b1717@kernel.org> (raw)
In-Reply-To: <20261028143534.135968-5-cui.tao@linux.dev>
Hello, Tao.
On Wed, Oct 28, 2026 at 10:35:33PM +0800, Tao Cui wrote:
> u64 vdone, vtime, usage_us;
> u32 hw_active, hw_inuse;
>
> + nr_active++;
nr_active is counted even when the tracepoint is disabled.
> + /*
> + * Everything the tick reports is final here: busy_level was just
> + * computed, cur_period hasn't changed, nr_active and usage_us_sum are
> + * complete, and vrate and period_us still hold the values this period
> + * ran in. usage is wall time over wall time, summed over iocgs, and is
An io.cost.qos write in the middle of a period changes both period_us
and vrate.
Thanks.
--
tejun
next prev parent reply other threads:[~2026-10-28 20:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-28 14:35 [RFC PATCH v11 0/5] blk-iocost: BPF struct_ops cost model Tao Cui
2026-10-28 14:35 ` [PATCH 1/5] blk-iocost: move shared definitions to blk-iocost.h Tao Cui
2026-10-28 20:09 ` Tejun Heo
2026-10-28 14:35 ` [PATCH 2/5] blk-iocost: add BPF struct_ops cost model support Tao Cui
2026-10-28 15:33 ` bot+bpf-ci
2026-10-28 20:09 ` Tejun Heo
2026-10-28 14:35 ` [PATCH 3/5] selftests/bpf: add iocost cost model test Tao Cui
2026-10-28 15:33 ` bot+bpf-ci
2026-10-28 20:09 ` Tejun Heo
2026-10-28 14:35 ` [PATCH 4/5] blk-iocost: add iocost_ioc_tick tracepoint for per-period device summary Tao Cui
2026-10-28 20:09 ` Tejun Heo [this message]
2026-10-28 14:35 ` [PATCH 5/5] docs: cgroup-v2: document the iocost BPF cost model attachment Tao Cui
2026-10-28 20:09 ` Tejun Heo
2026-10-28 15:58 ` [RFC PATCH v11 0/5] blk-iocost: BPF struct_ops cost model Alexei Starovoitov
2026-10-28 20:09 ` Tejun Heo
2026-10-28 20:09 ` Tejun Heo
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