Re: [PATCH v2] btrfs: zstd: use spin_lock in timer callback

From: David Sterba
Date: Thu Apr 14 2022 - 15:31:29 EST


On Mon, Apr 11, 2022 at 11:55:41PM +0800, Schspa Shi wrote:
> This is an optimization for fix fee13fe96529 ("btrfs:
> correct zstd workspace manager lock to use spin_lock_bh()")
>
> The critical region for wsm.lock is only accessed by the process context and
> the softirq context.
>
> Because in the soft interrupt, the critical section will not be preempted by the
> soft interrupt again, there is no need to call spin_lock_bh(&wsm.lock) to turn
> off the soft interrupt, spin_lock(&wsm.lock) is enough for this situation.
>
> Changelog:
> v1 -> v2:
> - Change the commit message to make it more readable.
>
> [1] https://lore.kernel.org/all/20220408181523.92322-1-schspa@xxxxxxxxx/
>
> Signed-off-by: Schspa Shi <schspa@xxxxxxxxx>

Added to misc-next, thanks.