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Date: Mon, 1 Jun 2026 09:32:20 +0200
From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
	Christoph Hellwig <hch@lst.de>, Damien Le Moal <dlemoal@kernel.org>,
	Tejun Heo <tj@kernel.org>, Josef Bacik <josef@toxicpanda.com>,
	Marco Elver <elver@google.com>
Subject: Re: [PATCH v5 08/12] block/blk-iocost: Add lock context annotations
Message-ID: <20260601073220.GD7799@lst.de>
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On Thu, May 28, 2026 at 12:45:45PM -0700, Bart Van Assche wrote:
> Since iocg_lock() and iocg_unlock() both use conditional locking,
> annotate both with __no_context_analysis and use token_context_lock() to
> introduce a new lock context.

Both of these are only called from two funtions.  Have you looked into
merging the locking logic into these helpers to see if this improves
the situation?  __no_context_analysis just seems like a big hammer
for something relatively simple like this.

> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  block/blk-iocost.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 353c165c5cd4..3bb8ce50af42 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -727,7 +727,11 @@ static void iocg_commit_bio(struct ioc_gq *iocg, struct bio *bio,
>  	put_cpu_ptr(gcs);
>  }
>  
> +token_context_lock(ioc_lock);
> +
>  static void iocg_lock(struct ioc_gq *iocg, bool lock_ioc, unsigned long *flags)
> +	__acquires(ioc_lock)
> +	__context_unsafe(conditional locking)
>  {
>  	if (lock_ioc) {
>  		spin_lock_irqsave(&iocg->ioc->lock, *flags);
> @@ -738,6 +742,8 @@ static void iocg_lock(struct ioc_gq *iocg, bool lock_ioc, unsigned long *flags)
>  }
>  
>  static void iocg_unlock(struct ioc_gq *iocg, bool unlock_ioc, unsigned long *flags)
> +	__releases(ioc_lock)
> +	__context_unsafe(conditional locking)
>  {
>  	if (unlock_ioc) {
>  		spin_unlock(&iocg->waitq.lock);
---end quoted text---