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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: D Scott Phillips <scott@os.amperecomputing.com>
Cc: Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] char: misc: Allow minors values up to MINORMASK
Date: Fri, 9 Sep 2022 10:42:31 +0200	[thread overview]
Message-ID: <Yxr8d3eCoPPldZU5@kroah.com> (raw)
In-Reply-To: <20220906195213.2370775-1-scott@os.amperecomputing.com>

On Tue, Sep 06, 2022 at 12:52:13PM -0700, D Scott Phillips wrote:
> For per-cpu coresight_tmc devices, we can end up with hundreds of devices
> on large systems that all want a dynamic minor number.  Switch the dynamic
> minors allocator to an ida and add logic to allocate in the ranges [0..127]
> and [256..MINORMASK]. Allocations start from 127 growing downwards and then
> increasing from 256, so device numbering for the first 128 devices should
> be the same as before.
> 
> Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
> ---
>  drivers/char/misc.c | 41 ++++++++++++++++++++++++++++-------------
>  1 file changed, 28 insertions(+), 13 deletions(-)

So you are adding more logic to the kernel for no change at all?

Why is this needed?  What changed here except the underlying data
structure being used?

thanks,

greg k-h

  reply	other threads:[~2022-09-09  8:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-06 19:52 [PATCH] char: misc: Allow minors values up to MINORMASK D Scott Phillips
2022-09-09  8:42 ` Greg Kroah-Hartman [this message]
2022-09-09 18:18   ` D Scott Phillips
2022-09-09 18:25     ` Greg Kroah-Hartman

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