linux-kernel - RE: [RFC 2/4] media: videobuf2: Replace bufs array by a list

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Message-ID: <dc04d48e34ed40e58f43badd001a81d0@AcuMS.aculab.com>
Date:   Tue, 14 Mar 2023 10:11:07 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Hans Verkuil' <hverkuil-cisco@...all.nl>,
        'Laurent Pinchart' <laurent.pinchart@...asonboard.com>,
        Benjamin Gaignard <benjamin.gaignard@...labora.com>
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Subject: RE: [RFC 2/4] media: videobuf2: Replace bufs array by a list

From: Hans Verkuil
> Sent: 14 March 2023 08:55
...
> Why not start with a dynamically allocated array of 32 vb2_buffer pointers?
> And keep doubling the size (reallocing) whenever more buffers are needed,
> up to some maximum (1024 would be a good initial value for that, I think).
> This max could be even a module option.

I don't know the typical uses (or the code at all).
But it might be worth having a small array in the structure itself.
Useful if there are typically always (say) less than 8 buffers.
For larger sizes use the (IIRC) kmalloc_size() to find the actual
size of the structure that will be allocate and set the array
size appropriately.

	David

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