Re: [PATCH] vmalloc : optimization, cleanup, bugfixes

From: Zwane Mwaikambo
Date: Mon Oct 30 2006 - 15:42:54 EST


On Mon, 23 Oct 2006, Nick Piggin wrote:

> Eric Dumazet wrote:
> > [PATCH] vmalloc : optimization, cleanup, bugfixes
> >
> > This patch does three things
> >
> > 1) reorder 'struct vm_struct' to speedup lookups on CPUS with small cache
> > lines. The fields 'next,addr,size' should be now in the same cache line, to
> > speedup lookups.
> >
> > 2) One minor cleanup in __get_vm_area_node()
> >
> > 3) Bugfixes in vmalloc_user() and vmalloc_32_user()
> > NULL returns from __vmalloc() and __find_vm_area() were not tested.
>
> Hmm, so they weren't. As far as testing the return of __find_vm_area,
> you can just turn that into a BUG_ON(!area), because at that point,
> we've established that the vmalloc succeeded.

No need for a BUG_ON it'll simply be a NULL dereference, at which point
we're back to the original code.

Zwane

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/