From: Jens Axboe <axboe@kernel.dk>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>,
Minchan Kim <minchan@kernel.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] zram: Replace bit spinlocks with spinlock_t for PREEMPT_RT.
Date: Wed, 19 Jun 2024 11:34:23 -0600 [thread overview]
Message-ID: <51f64ee9-35fb-482e-aa50-e2a446dcd972@kernel.dk> (raw)
In-Reply-To: <20240619150814.BRAvaziM@linutronix.de>
On 6/19/24 9:08 AM, Sebastian Andrzej Siewior wrote:
> From: Mike Galbraith <umgwanakikbuti@gmail.com>
>
> The bit spinlock disables preemption. The spinlock_t lock becomes a sleeping
> lock on PREEMPT_RT and it can not be acquired in this context. In this locked
> section, zs_free() acquires a zs_pool::lock, and there is access to
> zram::wb_limit_lock.
>
> Use a spinlock_t on PREEMPT_RT for locking and set/ clear ZRAM_LOCK bit after
> the lock has been acquired/ dropped.
The conditional code depending on CONFIG_PREEMPT_RT is nasty. Why not
just get rid of that and use the CONFIG_PREEMPT_RT variants for
everything? They are either good enough to work well in general, or it
should be redone such that it is.
--
Jens Axboe
next prev parent reply other threads:[~2024-06-19 17:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-19 15:08 [PATCH] zram: Replace bit spinlocks with spinlock_t for PREEMPT_RT Sebastian Andrzej Siewior
2024-06-19 17:34 ` Jens Axboe [this message]
2024-06-19 17:52 ` Sebastian Andrzej Siewior
2024-06-19 18:01 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2023-03-23 16:18 Sebastian Andrzej Siewior
2023-03-24 4:07 ` Sergey Senozhatsky
2023-03-24 4:32 ` Mike Galbraith
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