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From: Greg KH <greg@kroah.com>
To: Michael Hanselmann <public@hansmi.ch>
Cc: Johan Hovold <johan@kernel.org>, linux-usb@vger.kernel.org
Subject: Re: [PATCH] ch341: Replace memory allocations with stack storage
Date: Sun, 23 Feb 2020 11:02:11 +0100	[thread overview]
Message-ID: <20200223100211.GC120495@kroah.com> (raw)
In-Reply-To: <bdf7db0e0e133f55ac81d39ce9564653e0b5d9ed.1582312740.git.public@hansmi.ch>

On Fri, Feb 21, 2020 at 07:23:41PM +0000, Michael Hanselmann wrote:
> Storing a memory pointer consumes 4 or 8 bytes, depending on the
> architecture. The replaced buffers are 2 bytes, so this change not only
> avoids the overhead of memory allocation, but it also saves a small
> amount of stack storage.
> 
> Signed-off-by: Michael Hanselmann <public@hansmi.ch>
> ---
>  drivers/usb/serial/ch341.c | 32 ++++++++------------------------
>  1 file changed, 8 insertions(+), 24 deletions(-)

You should have gotten a runtime error with this change if you tested
it.  Did that not happen somehow?

As Johan said, all USB data has to be dynamically allocated.

thanks,

greg k-h

  parent reply	other threads:[~2020-02-23 10:02 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-21 19:23 [PATCH] ch341: Replace memory allocations with stack storage Michael Hanselmann
2020-02-22  9:50 ` Johan Hovold
2020-02-23 10:02 ` Greg KH [this message]
2020-02-23 10:06   ` Michael Hanselmann

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