[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH V2 3/6] [RFC] xen/common: Introduce _xrealloc function

On 05.08.19 13:02, Jan Beulich wrote:

Hi, Jan

While I can see why having a re-allocation function may be handy,
explicit / direct use of _xmalloc() and _xzalloc() are discouraged,
in favor of the more type-safe underscore-less variants.

took into account

I can't
see though how a type-safe "realloc" could look like, except for
arrays. If resizing arrays is all you're after, I'd like to
recommend to go that route rather then the suggested one here. If
resizing arbitrary objects is the goal, then what you suggest may
be the only route, but I'd still be not overly happy to see such

My main goal is to get "ported" from Linux "iommu_fwspec" support (xrealloc user) in [1].

I tried to retain code as much as possible while porting. So, this patch adds almost the same thing what the ported code expects.

But, I would be OK to consider modifying a code in a way to resize an array as well as any other variants if present.

Furthermore you don't even use internals of the allocator: It is
common practice to avoid re-allocation if the requested size fits
within the already allocated block. That's not the least helpful
because in such a case you can't possibly suffer any -ENOMEM

agree, took into account as well.

And finally - please note _xmalloc()'s and _xfree()'s use /
special casing of ZERO_BLOCK_PTR: You absolutely would need to
mirror this here.

got it, will use for zero-size allocation

[1] https://lists.xenproject.org/archives/html/xen-devel/2019-08/msg00257.html

Thank you.


Oleksandr Tyshchenko

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.