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From: Sven Eckelmann <sven@narfation.org>
Date: Sun, 15 May 2016 13:27:39 +0200
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Subject: Re: [B.A.T.M.A.N.] kmalloc() vs. kmem_cache_alloc() for global TT?
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On Saturday 14 May 2016 16:51:29 Linus L=FCssing wrote:
> Hi,
>=20
> Is anyone familiar with the implications of using kmalloc() vs.
> kmem_cache_alloc()? Not just allocation speed, but also RAM
> fragmentation is something I'm currently wondering about.

Yes, it should reduce the effects of allocating differently sized objec=
ts=20
(which can create smaller regions of memory which cannot be used anymor=
e). But=20
my guess is that SLAB isn't that bad because it already has some caches=
 for=20
differently sized memory regions.

I think we should check if this helps by first testing it with the main=
 TT=20
objects. I've send an RFC patch [1]. Unfortunately, I am not aware of a=
ny nice=20
tools to really check the size of the available, continuous memory chun=
ks. The=20
only thing partially interesting I know about is /proc/slabinfo which s=
hows=20
you the state of the available caches (including the slab page caches).=


Kind regards,
=09Sven=20

[1] https://patchwork.open-mesh.org/patch/16200/

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