From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Documentation of locking needs when working with lists?
Date: Sat, 10 May 2025 15:20:47 +0200 [thread overview]
Message-ID: <2025051012-karma-setting-af04@gregkh> (raw)
In-Reply-To: <4f405d9b-460c-49f7-91b2-d147d9818369@gmail.com>
On Sat, May 10, 2025 at 10:46:32AM +0200, Heiner Kallweit wrote:
> Even though lists are used everywhere, I was surprised not being able to find
> documentation about which operations need locking, and which ones are safe
> lock-less.
>
> My case:
> I have a list where the only operation is adding entries.
> It's clear that adding entries has to be serialized.
> Question is whether a list_for_each_entry is safe lock-less.
>
> Looking at the code I *think* it's safe, under the precondition that
> reading/writing pointers is atomic.
>
> Any hint or documentation link would be appreciated. Thanks!
You MUST have locking for your list if you have multiple processes
accessing it at the same time.
good luck!
greg k-h
next prev parent reply other threads:[~2025-05-10 13:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-10 8:46 Documentation of locking needs when working with lists? Heiner Kallweit
2025-05-10 13:20 ` Greg Kroah-Hartman [this message]
2025-05-10 20:46 ` Heiner Kallweit
2025-05-13 21:42 ` David Laight
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