[v2,0/3] zram: Replace bit spinlocks with a spinlock_t.

Message ID	20240620153556.777272-1-bigeasy@linutronix.de (mailing list archive)
Headers	show Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66E9D1AED4D; Thu, 20 Jun 2024 15:36:10 +0000 (UTC) From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Minchan Kim <minchan@kernel.org>, Sergey Senozhatsky <senozhatsky@chromium.org>, Jens Axboe <axboe@kernel.dk>, Thomas Gleixner <tglx@linutronix.de>, Mike Galbraith <umgwanakikbuti@gmail.com> Subject: [PATCH v2 0/3] zram: Replace bit spinlocks with a spinlock_t. Date: Thu, 20 Jun 2024 17:28:49 +0200 Message-ID: <20240620153556.777272-1-bigeasy@linutronix.de> Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Series	zram: Replace bit spinlocks with a spinlock_t. \| expand [v2,0/3] zram: Replace bit spinlocks with a spinlock_t. [v2,1/3] zram: Replace bit spinlocks with a spinlock_t. [v2,2/3] zram: Remove ZRAM_LOCK [v2,3/3] zram: Shrink zram_table_entry::flags.

Message ID

20240620153556.777272-1-bigeasy@linutronix.de (mailing list archive)

Headers

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Minchan Kim <minchan@kernel.org>,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	Jens Axboe <axboe@kernel.dk>,
	Thomas Gleixner <tglx@linutronix.de>,
	Mike Galbraith <umgwanakikbuti@gmail.com>
Subject: [PATCH v2 0/3] zram: Replace bit spinlocks with a spinlock_t.
Date: Thu, 20 Jun 2024 17:28:49 +0200
Message-ID: <20240620153556.777272-1-bigeasy@linutronix.de>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Series

zram: Replace bit spinlocks with a spinlock_t. | expand

Message

Sebastian Andrzej Siewior June 20, 2024, 3:28 p.m. UTC

Hi,

this is follow up to the previous posting, making the lock
unconditionally. The original problem with bit spinlock is that it
disabled preemption and the following operations (within the atomic
section) perform operations that may sleep on PREEMPT_RT. Mike expressed
that he would like to keep using zram on PREEMPT_RT.

v1…v2: https://lore.kernel.org/all/20240619150814.BRAvaziM@linutronix.de/:
  - Add the spinlock_t unconditionally
  - Remove ZRAM_LOCK since it has no user after the lock has been added.
  - Make zram_table_entry::flags an integer so struct zram_table_entry
    does not gain additional weight.

Sebastian