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Date: Wed, 20 Mar 2002 12:48:37 +0100
From: Jan Hudec <bulb@ucw.cz>
To: linux-kernel@vger.kernel.org
Subject: Re: using kmalloc
Message-ID: <20020320114837.GA5421@artax.karlin.mff.cuni.cz>
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> kmalloc() allocates physically-contiguous pages of memory. Due to
> fragmentation, more than 64KB-128KB of contiguous pages might not be
> available, and hence kmalloc() will fail.

kmalloc allocates from generic slab caches. They come in sizes of powers
of 2 from 32B to 128KiB. The largest has slabs 128KiB large (on i386 at least).
Pages are allocated via __get_free_pages, so they have to be continuous.

However if you allocate namy instances of some structure, it's best to create
a kmem cache and allocate via kmem_cache_alloc (since it does not round the
requested size up to a power of two).

--------------------------------------------------------------------------------
                  				- Jan Hudec `Bulb' <bulb@ucw.cz>
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