Re: [PATCH v10 Golden] Unified trace buffer

From: Linus Torvalds
Date: Tue Sep 30 2008 - 13:09:05 EST




On Tue, 30 Sep 2008, Steven Rostedt wrote:
>
> But I just realized that I could also just make a link list of page
> pointers and do the exact same thing without having to worry about page
> frames. Again, the way I coded this up, it is quite trivial to replace
> the handling of the pages with other schemes.

That might be the best option.

Yes, doing it in the 'struct page' itself is obviously going to save us
some memory over having specially allocated page headers, but it's not
like we'd expect to have _that_ many of these, and having a separate
structure is actually good in that it also would make it simpler/clearer
when/if you want to add larger pages (or other non-page allocations) into
the mix.

For example, if somebody really wants bigger areas, they can allocate them
with vmalloc and/or multi-page allocations, and then add them as easily to
the list of pages as if it was a normal page. Doing the same with playing
tricks on 'struct page' would be pretty damn painful.

Linus
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