Re: [PATCH] use vmalloc for mem_cgroup allocation. v2

From: KAMEZAWA Hiroyuki
Date: Mon Apr 14 2008 - 23:19:39 EST


On Tue, 15 Apr 2008 11:14:24 +0800
Li Zefan <lizf@xxxxxxxxxxxxxx> wrote:

> KAMEZAWA Hiroyuki wrote:
> > On Mon, 14 Apr 2008 19:17:30 -0700
> > Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> >> Well... vmalloced memory is of course a little slower to use - additional
> >> TLB pressure.
> >>
> >> Do you think the memcgroup is accessed frequently enough to use vmalloc()
> >> only on those architectures which actually need it?
> >>
> >> Because it'd be pretty simple to implement:
> >>
> >> if (sizeof(struct mem_group) > PAGE_SIZE)
> >> vmalloc()
> >> else
> >> kmalloc()
> >>
> >> ...
> >>
> >> if (sizeof(struct mem_group) > PAGE_SIZE)
> >> vfree()
> >> else
> >> kfree()
> >>
> >> the compiler will optimise away the `if'.
> >>
> >
> > Hmm, ok. I'll rewrite one to do that.
> >
>
> It will be better to use wrappers for these: mem_cgroup_alloc() and mem_cgroup_free()
>
yes. will do

-Kame
> > Thanks,
> > -Kame
> >
> >
> >
>

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