From: Josh Law <hlcj1234567@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
Josh Law <objecting@objecting.org>
Subject: Re: [PATCH] staging: axis-fifo: minimize lock duration in write
Date: Mon, 9 Mar 2026 16:11:25 +0000 [thread overview]
Message-ID: <07e2ae8e-e6e9-4def-9eb2-2c48ce6669b8@gmail.com> (raw)
In-Reply-To: <2026030914-task-stunned-21e0@gregkh>
9 Mar 2026 16:07:50 Greg Kroah-Hartman <gregkh@linuxfoundation.org>:
> On Sun, Mar 01, 2026 at 12:58:36AM +0000, Josh Law wrote:
>> Memory allocation and copy from user space with vmemdup_user() is relatively slow and can sleep. Move it outside the lock to minimize the time the mutex is held, reducing contention for concurrent accesses.
>
> Something happened with your line wrapping :(
>
> And are you sure that your change works? What is wrong with grabbing
> the lock this way?
>
> thanks,
>
> greg k-h
The issue with grabbing the lock before vmemdup_user() is that the allocation and user-space copy can take a significant amount of time and can sleep.
Also, it's just to be more efficient haha, and yes I'm sure this change works, I own the hardware, and it operates better...
V/R
Josh law
next prev parent reply other threads:[~2026-03-09 16:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-01 0:58 [PATCH] staging: axis-fifo: minimize lock duration in write Josh Law
2026-03-01 18:39 ` Ethan Tidmore
2026-03-09 16:07 ` Greg Kroah-Hartman
2026-03-09 16:11 ` Josh Law [this message]
2026-03-09 16:56 ` Greg Kroah-Hartman
2026-03-09 17:04 ` Josh Law
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