Messages in this thread | | | Date | Tue, 08 Apr 2008 10:44:51 -0700 | From | "H. Peter Anvin" <> | Subject | Re: bootmem allocator |
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Andi Kleen wrote: > On Tue, Apr 08, 2008 at 10:04:46AM +0200, Ingo Molnar wrote: >> * Andi Kleen <andi@firstfloor.org> wrote: >> >>>> hm, bootmem allocator is supposed to clear memory. We have a couple >>>> of places that rely on that. >>> I was actually considering to change that for the GB pages hugetlbfs >>> patchkit, because memset for 1G is a little slow and not needed (will >>> be cleared later anyways) and it might be a problem for very large >>> systems with a lot of such pages at boot. >> changing the default behavior of bootmem alloc to be non-clearing is a >> really bad idea that will only cause unrobustness. The proper approach >> is to add an _opt-in_ API that does not clear memory > > I was considering that too, but we have so many weird variants of bootmem > with opt in and opt out and even combinations of both now that the whole thing > is starting to look really pear shaped (I admit I added some of them > in the past myself but I'm not proud). Would be a great project for > someone to consolidate that all a bit. >
True, but if the gbpages hugetlbfs case is the *only* case which wants a nonclearing interface (which it sounds like it is), then it seems like a really bad idea to change the default.
hugetlbfs is a pretty special case.
-hpa
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