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From:   Sandeep Dhavale <dhavale@google.com>
Date:   Mon, 22 May 2023 19:32:05 -0700
Message-ID: <CAB=BE-TQsa+D9WZ01Zi_ByAjaLMcHGZBXAuGzmRSEdgeio7UJA@mail.gmail.com>
Subject: Re: [PATCH] erofs: use HIPRI by default if per-cpu kthreads are enabled
To:     Gao Xiang <hsiangkao@linux.alibaba.com>
Cc:     linux-erofs@lists.ozlabs.org, LKML <linux-kernel@vger.kernel.org>
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On Mon, May 22, 2023 at 2:21=E2=80=AFAM Gao Xiang <hsiangkao@linux.alibaba.=
com> wrote:
>
> As Sandeep shown [1], high priority RT per-cpu kthreads are
> typically helpful for Android scenarios to minimize the scheduling
> latencies.
>
> Switch EROFS_FS_PCPU_KTHREAD_HIPRI on by default if
> EROFS_FS_PCPU_KTHREAD is on since it's the typical use cases for
> EROFS_FS_PCPU_KTHREAD.
>
> Also clean up unneeded sched_set_normal().
>
> [1] https://lore.kernel.org/r/CAB=3DBE-SBtO6vcoyLNA9F-9VaN5R0t3o_Zn+FW8Gb=
O6wyUqFneQ@mail.gmail.com
> Cc: Sandeep Dhavale <dhavale@google.com>
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
>  fs/erofs/Kconfig | 1 +
>  fs/erofs/zdata.c | 2 --
>  2 files changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
> index 704fb59577e0..f259d92c9720 100644
> --- a/fs/erofs/Kconfig
> +++ b/fs/erofs/Kconfig
> @@ -121,6 +121,7 @@ config EROFS_FS_PCPU_KTHREAD
>  config EROFS_FS_PCPU_KTHREAD_HIPRI
>         bool "EROFS high priority per-CPU kthread workers"
>         depends on EROFS_FS_ZIP && EROFS_FS_PCPU_KTHREAD
> +       default y
>         help
>           This permits EROFS to configure per-CPU kthread workers to run
>           at higher priority.
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index 92f3a01262cf..3ba505434f03 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -367,8 +367,6 @@ static struct kthread_worker *erofs_init_percpu_worke=
r(int cpu)
>                 return worker;
>         if (IS_ENABLED(CONFIG_EROFS_FS_PCPU_KTHREAD_HIPRI))
>                 sched_set_fifo_low(worker->task);
> -       else
> -               sched_set_normal(worker->task, 0);
>         return worker;
>  }
>
> --
> 2.24.4
>
Looks good!

Reviewed-by: Sandeep Dhavale <dhavale@google.com>