From: Ammar Faizi <[email protected]>
To: Qu Wenruo <[email protected]>
Cc: Chris Mason <[email protected]>, Josef Bacik <[email protected]>,
David Sterba <[email protected]>, Tejun Heo <[email protected]>,
Lai Jiangshan <[email protected]>,
Filipe Manana <[email protected]>,
Linux Btrfs Mailing List <[email protected]>,
Linux Kernel Mailing List <[email protected]>,
Linux Fsdevel Mailing List <[email protected]>,
GNU/Weeb Mailing List <[email protected]>
Subject: Re: [RFC PATCH v1 0/6] Introducing `wq_cpu_set` mount option for btrfs
Date: Mon, 27 Feb 2023 20:42:35 +0700 [thread overview]
Message-ID: <Y/[email protected]> (raw)
In-Reply-To: <[email protected]>
On Mon, Feb 27, 2023 at 06:18:43PM +0800, Qu Wenruo wrote:
> I'm not sure if pinning the wq is really the best way to your problem.
>
> Yes, I understand you want to limit the CPU usage of btrfs workqueues, but
> have you tried "thread_pool=" mount option?
>
> That mount option should limit the max amount of in-flight work items, thus
> at least limit the CPU usage.
I have tried to use the thread_poll=%u mount option previously. But I
didn't observe the effect intensively. I'll try to play with this option
more and see if it can yield the desired behavior.
> For the wq CPU pinning part, I'm not sure if it's really needed, although
> it's known CPU pinning can affect some performance characteristics.
What I like about CPU pinning is that we can dedicate CPUs for specific
workloads so it won't cause scheduling noise to the app we've dedicated
other CPUs for.
--
Ammar Faizi
next prev parent reply other threads:[~2023-02-27 13:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-26 16:02 [RFC PATCH v1 0/6] Introducing `wq_cpu_set` mount option for btrfs Ammar Faizi
2023-02-26 16:02 ` [RFC PATCH v1 1/6] workqueue: Add set_workqueue_cpumask() helper function Ammar Faizi
2023-02-26 16:02 ` [RFC PATCH v1 2/6] btrfs: Change `mount_opt` type in `struct btrfs_fs_info` to `u64` Ammar Faizi
2023-02-26 16:02 ` [RFC PATCH v1 3/6] btrfs: Create btrfs CPU set struct and helpers Ammar Faizi
2023-02-26 16:02 ` [RFC PATCH v1 4/6] btrfs: Add wq_cpu_set=%s mount option Ammar Faizi
2023-02-26 16:02 ` [RFC PATCH v1 5/6] btrfs: Adjust the default thread pool size when `wq_cpu_set` option is used Ammar Faizi
2023-02-26 16:02 ` [RFC PATCH v1 6/6] btrfs: Add `BTRFS_DEFAULT_MAX_THREAD_POOL_SIZE` macro Ammar Faizi
2023-02-26 17:01 ` [RFC PATCH v1 0/6] Introducing `wq_cpu_set` mount option for btrfs Tejun Heo
2023-02-26 18:26 ` Ammar Faizi
2023-02-26 18:29 ` Ammar Faizi
2023-02-27 10:18 ` Qu Wenruo
2023-02-27 13:42 ` Ammar Faizi [this message]
2023-02-27 23:49 ` Qu Wenruo
2023-02-27 11:02 ` Filipe Manana
[not found] ` <[email protected]>
2023-02-27 13:45 ` Ammar Faizi
2023-02-27 16:24 ` Roman Mamedov
2023-02-27 22:17 ` Dave Chinner
2023-02-28 8:01 ` Ammar Faizi
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