Messages in this thread |  | | Date | Sat, 15 Nov 2008 21:03:34 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 1/7] mm: introduce simple_malloc()/simple_free() |
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On Sat, 15 Nov 2008 20:52:29 -0800 Arjan van de Ven <arjan@infradead.org> wrote:
> On Sun, 16 Nov 2008 12:33:15 +0800 > Lai Jiangshan <laijs@cn.fujitsu.com> wrote: > > > > > some subsystem needs vmalloc() when required memory is large. > > but current kernel has not APIs for this requirement. > > this patch introduces simple_malloc() and simple_free(). > > Hi > > I kinda really don't like this approach. vmalloc() (and especially, > vfree()) is a really expensive operation, and vmalloc()'d memory is > also slower (due to tlb pressure).
And it can fragment, which effectively means a dead box.
> Realistically, people should try hard > to use small datastructure instead....
Yup, it makes it easier for people to do something which we strongly discourage. The risk got worse with all these 64-bit machines with vast amounts of virtual address space. It makes it easier for people to develop and "test" code which isn't reliable on smaller machines.
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